Applied Pharmacology for the Dental Hygienist 7th Edition by Elena Bablenis Haveles – Test Bank A+

Description

1. Enkephalins, endorphins, and dynorphins probably function as _____, although their exact function has not been elucidated.

a.	prostaglandins
b.	neurotransmitters
c.	sedative-hypnotics
d.	enzymes

ANS: B

Correct: Enkephalins, endorphins, and dynorphins are endogenous substances with opioid-like action. They probably function as neurotransmitters. They may be involved in the analgesic action of a placebo and the enhancement of well-being that occurs with running.

Incorrect choices: Prostaglandins are produced in the body in response to many different stimuli. Prostaglandins are thought to be mediators of the inflammatory response in oral soft tissues and may be involved in the initial stage of periodontal disease. Sedative-hypnotics produce varying degrees of central nervous system (CNS) depression depending on the dose administered. Examples include benzodiazepines, barbiturates, and nonbenzodiazepine-nonbarbiturate sedative-hypnotics. An enzyme is a substance that catalyzes a chemical reaction without being changed by it.

REF: Mechanism of Action | p. 60 OBJ: 1

1. Beta-endorphin is a naturally occurring peptide with opioid-like action. It possesses analgesic action but has no addiction potential.

a.	Both statements are true.
b.	Both statements are false.
c.	The first statement is true; the second statement is false.
d.	The first statement is false; the second statement is true.

ANS: C

Correct: Endorphins, enkephalins, and dynorphins are naturally occurring peptides with opioid-like action.

Incorrect choices: Endorphins, enkephalins, and dynorphins possess analgesic action and have addiction potential. An increase in beta-endorphins is associated with “runners high,” the enhancement of well-being associated with running.

REF: Mechanism of Action | p. 60 OBJ: 1

1. Morphine has its most potent action on the _____ class of opioid receptors, and pentazocine has its most potent action on the _____ class of opioid receptors.

a.	mu; kappa
b.	mu; delta
c.	sigma; delta
d.	kappa; mu
e.	delta; kappa

ANS: A

Correct: The three opioid receptors that have been characterized in more detail and that are stimulated by the opioids are the mu, kappa, and delta receptors. Other opioid receptors include sigma and epsilon. Stimulation of sigma receptors is associated with autonomic stimulation, dysphoria, hallucinations, nightmares, and anxiety. It is thought that stimulation of epsilon receptors may result in analgesia. Morphine is a mu-receptor agonist, and pentazocine is a kappa-receptor agonist.

Incorrect choices: Stimulation of mu receptors produces analgesia. Stimulation of kappa receptors produces dysphoria. Morphine has no effect on the kappa receptor and produces less dysphoria than pentazocine. Pentazocine is a kappa receptor agonist that produces dysphoria.

REF: Mechanism of Action | p. 61 OBJ: 1

1. Oral bioavailability of opioids is primarily limited by:

a.	incomplete absorption.
b.	first-pass metabolism.
c.	side effects of nausea and vomiting.
d.	enterohepatic circulation.
e.	rapid renal excretion.

ANS: B

Correct: The opioids undergo variable first-pass metabolism in the liver or intestinal cell wall, which reduces their bioavailability.

Incorrect choices: Most opioid analgesic agents are absorbed well when taken orally. Opiates need to be available before they cause the side effects of nausea and vomiting. Most opioids are excreted through the kidneys, but this action does not selectively affect their availability after oral administration.

REF: Pharmacokinetics | p. 61 OBJ: 1

1. Which of the following statements is true concerning the pharmacokinetics of opioid analgesics?

a.	Absorption may occur through mucous membranes of the nose but is not possible through intact skin.
b.	The opioids are bound to plasma proteins to varying degrees and distributed throughout the body.
c.	Given orally, opioids have vastly different durations of action for analgesia, ranging from 1 to almost 12 hours.
d.	Metabolized opioids are excreted in urine; however, the unchanged drug is not.

ANS: B

Correct: Drugs such as opioids are bound reversibly to plasma proteins such as albumin and globulin. The drug that is bound to the protein does not contribute to the intensity of the drug action because only the unbound form is biologically active.

Incorrect choices: Absorption occurs through the mucous membranes of the nose and the intact skin. Given orally, most opioids have a similar duration of action for analgesia—4 to 6 hours. Metabolized opioids and the unchanged drug are excreted in the urine.

REF: Pharmacokinetics | p. 61 OBJ: 1

1. What do aspirin, acetaminophen, ibuprofen, and codeine have in common?

a.	They are all antiinflammatory.
b.	They are all analgesic.
c.	They all inhibit platelet aggregation.
d.	They are all antipyretic.

ANS: B

Correct: All of them are analgesic.

Incorrect choices: Aspirin and ibuprofen are analgesic, antipyretic, and antiinflammatory, and they inhibit platelet aggregation. Acetaminophen is analgesic and antipyretic. Codeine is analgesic.

REF: Table 6-6: Make-Up of Common Opioid Analgesic Products | p. 66

OBJ: 2

1. Which opioid is commonly used as an antitussive?

a.	Propoxyphene
b.	Codeine
c.	Diphenoxylate
d.	Pentazocine

ANS: B

Correct: Opioids work to suppress cough by depressing the cough center in the medulla. The least potent opioids are effective because the dose that produces the antitussive effect is much lower than the dose needed for analgesia, so the least potent opioids, such as codeine, are effective.

Incorrect choices: Propoxyphene is found in Darvocet N-100. Diphenoxylate is in Lomotil, which is used to treat diarrhea. Pentazocine produces central nervous system (CNS) effects not unlike the opioid agonists, including analgesia, sedation, and respiratory depression.

REF: Pharmacologic Effects (Cough Suppression) | p. 62 OBJ: 1

1. _____ is usually the cause of death with an overdose of opioids.

a.	Tachycardia
b.	Respiratory depression
c.	Electrolyte imbalance
d.	Cellular necrosis

ANS: B

Correct: The opioid analgesic agonists depress the respiratory center in a dose-related manner. This action is usually the cause of death with an overdose. The depression is related to a decrease in the sensitivity of the brainstem to carbon dioxide. Both the rate and the depth of breathing are reduced.

Incorrect choices: Opioids may depress the vasomotor center and stimulate the vagus nerve. Postural hypotension, bradycardia, and even syncope may result with high doses. Opioids can increase the smooth muscle tone in the urinary tract and cause urinary retention; however, this is not the primary cause of death. Cellular necrosis occurs following an injury and is not the predominant cause of death due to an overdose of opioids.

REF: Adverse Reactions (Respiratory Depression) | p. 63 OBJ: 2

1. Which one of the following conditions can be managed or treated with opioids?

a.	Diarrhea
b.	Depression
c.	Infections
d.	Hypertension

ANS: A

Correct: The opioids produce constipation by producing a tonic contraction of the gastrointestinal tract. They are used for the treatment of diarrhea.

Incorrect choices: Opioids are not used for the treatment of depression, infections, or hypertension.

REF: Pharmacologic Effects (Gastrointestinal Effects) | p. 62 OBJ: 2

1. Which of the following conditions is an adverse reaction to the opioids?

a.	Diarrhea
b.	Miosis
c.	CNS excitation
d.	Hepatotoxicity

ANS: B

Correct: The opioid analgesics cause miosis (pinpoint pupils), an important sign in diagnosing an opioid overdose or identifying an addict.

Incorrect choices: Opioids produce constipation and CNS sedation. They are not associated with hepatotoxicity.

REF: Adverse Reactions (Miosis) | p. 63 OBJ: 2

1. The following are conditions for which opioid analgesics should be used with extreme caution or not at all except which one?

a.	Head injury
b.	Nausea
c.	Respiratory disease
d.	Hypertension
e.	Near-term pregnancy

ANS: D

Correct: Use of opioids is not contraindicated in hypertensive patients. Opioids may stimulate the vagus nerve, which causes bradycardia, a decrease in heart rate.

Incorrect choices: Opioids are contraindicated for patients with head injury because they can increase intracranial pressure, nausea because they can exacerbate nausea, respiratory depression because they are additive, and near-term pregnancy because they are associated with near term fetal respiratory depression.

REF: Table 6-4: Contraindications to and Cautions for the Use of Opioids | p. 63

OBJ: 1

1. A patient presents with itching and urticaria after codeine administration. This response most likely represents a:

a.	pharmacologic action of codeine.
b.	hypersensitivity reaction to codeine.
c.	placebo effect from receiving codeine.
d.	reaction unrelated to codeine administration.

ANS: A

Correct: The response is a pharmacologic action of codeine. Opioids can stimulate the release of histamine. Itching and urticaria can result from their administration.

Incorrect choices: Although possible, true opioid allergy is very uncommon. Although a placebo effect may be observed with any drug, this choice is less likely. The reaction is probably related and a pharmacologic action of codeine.

REF: Adverse Reactions (Histamine Release) | p. 63 OBJ: 3

1. Which is an advantage of the nonsteroidal antiinflammatory drugs (NSAIDs) over the opioids for the management of dental pain in an opioid addict?

a.	They are not addictive.
b.	They are antitussive.
c.	They are all useful if the patient is pregnant.
d.	They cause less fluid retention (edema).

ANS: A

Correct: NSAIDs are not addictive, tolerance does not develop, and no withdrawal syndrome can be induced. NSAIDs should be used to control dental pain in the addict.

Incorrect choices: NSAIDs are not antitussive, some are less useful than others in pregnant women, and NSAIDs can cause decreased renal function, leading to peripheral edema formation.

REF: Adverse Reactions (Addiction) | p. 63 OBJ: 3

1. Tolerance occurs to the following effects of the opioids except which one?

a.	Miosis
b.	Analgesia
c.	Respiratory depression
d.	Nausea
e.	Histamine release

ANS: A

Correct: Tolerance will not develop to miosis and constipation. The rate is related to the strength of the opioid and its frequency of use.

Incorrect choices: It can develop to all of the other listed effects. Tolerance is normally not a problem for those who take opioid analgesics for no more than 1 to 3 days as is the case with managing dental-related pain. Because the duration of use in dentistry is usually short, addiction does not often pose a problem for the dentist.

REF: Adverse Reactions (Addiction) | pp. 63-64 OBJ: 3

1. Which is the major symptom of opioid overdose?

a.	Miosis
b.	Mydriasis
c.	Urticaria
d.	Respiratory depression

ANS: D

Correct: Respiratory depression occurs with opioid overdose, and this symptom can lead to death.

Incorrect choices: Opioids cause miosis, not mydriasis, but the former is not a life-threatening symptom. Urticaria can be caused by opioids, but this is not life threatening in an overdose situation either.

REF: Adverse Reactions (Overdose) | p. 64 OBJ: 3

1. Which of the following drugs can be used to treat heroin addiction?

a.	Hydromorphone
b.	Methadone
c.	Naltrexone
d.	Both a and c
e.	Both b and c

ANS: E

Correct: Methadone is used by substituting methadone for heroin and then tapering off or maintaining the addict on oral methadone. Naltrexone, a long-acting opioid antagonist, is used to block the action of usual doses of opioid administered illicitly.

Incorrect choices: Hydromorphone (Dilaudid) is the most potent opioid analgesic on a milligram-for-milligram basis. It is used to treat severe pain. It is a Schedule II narcotic and is not used to treat heroin addiction.

REF: Adverse Reactions (Treatment) | p. 64 OBJ: 3

1. Which of the following opioids is a metabolite of oxycodone that is three times more potent than oral morphine?

a.	Codeine
b.	Hydrocodone
c.	Hydromorphone
d.	Oxymorphone

ANS: D

Correct: Oxymorphone is a metabolite of oxycodone that is available as parenteral short- and long-acting oral dose forms. It is three times more potent than oral morphine and provides adequate pain relief in cancer patients that have been switched from long-acting morphine or oxycodone.

Incorrect choices: Codeine has a relatively weak analgesic action compared with morphine, hydromorphone, hydrocodone, or even oxycodone. Hydrocodone is a synthetic opioid that is metabolized to hydromorphone after oral administration. Hydromorphone is more potent that morphine and better absorbed orally, but it tends to produce similar adverse reactions.

REF: Specific Opioids (Oxymorphone) | p. 65 OBJ: 3

1. Which of the following products is the most commonly used opioid in dentistry?

a.	Hydrocodone (Vicodin)
b.	Morphine
c.	Codeine
d.	Oxymorphone

ANS: C

Correct: Codeine is the most commonly used opioid in dentistry. It is used for moderate pain. It is often combined with acetaminophen (Tylenol #3) for oral administration. When codeine is combined with nonopioid analgesics, there is additive analgesic activity. In the combination products, lower doses of each analgesic may be used and there is potential for a reduction in adverse reactions.

Incorrect choices: Hydrocodone, morphine, and oxymorphone are not the most commonly used opioids in dentistry. Hydrocodone (Valium) is a synthetic opioid used for moderate pain. There is a movement to reclassify hydrocodone combinations to Schedule II from Schedule III. Morphine and oxymorphone are used for severe pain.

REF: Specific Opioids (Codeine) | p. 67 OBJ: 4

1. Tylenol #3 contains _____ mg of codeine.

a.	7.5
b.	15
c.	30
d.	60

ANS: C

Correct: Tylenol #3 contains 30 mg of codeine. Generally, doses greater than 30 to 60 mg of codeine are poorly tolerated by the patient (too much nausea). In pain studies, showing that 30 mg of codeine is any better than a placebo is difficult, and 60 mg of codeine has an analgesic strength approximately the same as 650 mg of aspirin, 650 mg of acetaminophen, or 200 mg of ibuprofen.

Incorrect choices: Tylenol #1 contains 7.5 mg of codeine, Tylenol #2 contains 15 mg of codeine, and Tylenol #4 contains 60 mg of codeine.

REF: Table 6-3: Selected Opioid Analgesics by Efficacy, Dosing Interval, Usual Doses, and Schedule | p. 62 OBJ: 4

1. Which of the following opioids is used primarily in the treatment of opioid addicts?

a.	Propoxyphene
b.	Meperidine
c.	Hydromorphone
d.	Methadone

ANS: D

Correct: Methadone is used either to withdraw the patient gradually or for methadone maintenance. Because it has a longer duration of action, withdrawal from methadone is easier than from heroin. Because it is an opioid analgesic, however, the risk for dependence still exists.

Incorrect choices: Propoxyphene is in Darvocet N-100; its analgesic efficacy has been questioned, and it is certainly no more efficacious than two tablets of aspirin or acetaminophen. Meperidine is intended for the acute management of moderate-to-severe pain. Hydromorphone is reserved for the management of severe pain.

REF: Specific Opioids (Methadone) | p. 67 OBJ: 4

1. Which of the following agents is a potent, short-acting, parenterally administered opioid that is commonly used during general anesthesia?

a.	Dynorphin
b.	Hydromorphone
c.	Nalmefene
d.	Fentanyl
e.	Tramadol

ANS: D

Correct: Fentanyl is a short-acting, parenterally administered agonist opioid analgesic that is used perioperatively or during general anesthesia.

Incorrect choices: Dynorphin is an endogenous opioid. Hydromorphone is reserved for the management of severe pain. Nalmefene is an opioid antagonist. Tramadol is an orally administered nonopioid with weak analgesic activity.

REF: Specific Opioids (Fentanyl Family) | p. 67 OBJ: 4

1. Which opioid analgesic is most likely to produce dysphoria?

a.	Meperidine
b.	Codeine
c.	Pentazocine
d.	Oxycodone
e.	Hydrocodone

ANS: C

Correct: Of the agents listed, pentazocine has the greatest propensity for causing dysphoric reactions. It is a mixed agonist-antagonist opioid, and produces CNS effects not unlike the opioid agonists, including analgesia, sedation, and respiratory depression. The type of analgesia it produces is somewhat different from that produced by the agonist opioids. This may be a result of its agonist action on kappa and delta receptors and its antagonist action at the mu receptor. References differ whether sigma or delta opioid receptors may be responsible for the dysphoria.

Incorrect choices: Meperidine, codeine, oxycodone, and hydrocodone are opioid agonists. They are not the primary opioid associated with dysphoria.

REF: Mechanism of Action | p. 61 OBJ: 5

1. How does adding naloxone to pentazocine reduce the addiction potential of orally administered pentazocine?

a.	Naloxone is an opioid agonist that is effective orally but not parenterally.
b.	Naloxone is an opioid agonist that is effective parenterally but not orally.
c.	Naloxone is an opioid antagonist that is effective orally but not parenterally.
d.	Naloxone is an opioid antagonist that is effective parenterally but not orally.
e.	Naloxone is a nonsteroidal anti-inflammatory.

ANS: D

Correct: Naloxone is a pure opioid antagonist. It is effective parenterally but not orally because it is inactivated. If the tablet is taken by the oral route, the naloxone will not affect the analgesic potency of the pentazocine. If the contents of the tablet are injected parenterally, the naloxone will be active and will counteract the effects of the pentazocine.

Incorrect choices: Naloxone is not an opioid agonist and it is inactivated when taken orally. It is not a nonsteroidal anti-inflammatory drug.

REF: Specific Opioids (Agonist-Antagonist Opioids) | p. 67 OBJ: 5

1. Which of the following agents is the only mixed opioid available for oral use?

a.	Dezocine
b.	Nalbuphine
c.	Pentazocine
d.	Butorphanol

ANS: C

Correct: Pentazocine is the only mixed opioid available for oral use. Butorphanol, available as a nasal spray, is also in this group.

Incorrect choices: Dezocine, nalbuphine, and butorphanol are parenterally available agonist-antagonists. Dezocine has agonist action at the kappa (k) receptor and antagonist action at the mu (m) receptor.

REF: Specific Opioids (Mixed Opioids) | p. 67 OBJ: 5

1. Which of the following choices is the drug of choice to treat a patient who has taken an overdose of an opioid?

a.	2-pralidoxime
b.	Naloxone
c.	N-acetylcysteine
d.	Activated charcoal
e.	Methadone

ANS: B

Correct: Naloxone is an opioid antagonist that will block the therapeutic and toxic actions of opioids; the others are not.

Incorrect choices: Pralidoxime is used to treat an overdose of cholinesterase inhibitors such as insecticides or organophosphates. Acetylcysteine is a mucolytic used to loosen secretions in pulmonary diseases. Activated charcoal is used for the emergency treatment of certain poisonings. Methadone is an opioid used in treatment of addiction, but will exacerbate symptoms of an opioid overdose.

REF: Specific Opioids (Naloxone) | p. 68 OBJ: 5

1. Tapentadol is an oral opioid receptor _____ and a _____ reuptake inhibitor.

a.	agonist; norepinephrine
b.	agonist; acetylcholine
c.	antagonist; norepinephrine
d.	antagonist; acetylcholine

ANS: A

Correct: Tapentadol is classified as a full opioid agonist norepinephrine reuptake inhibitor. It has oral administration in an extended release formula that appears to be similar in efficacy to extended-release oxycodone for osteoarthritis and lower back pain. The drug’s labeling carries a warning for the possibility of serotonergic syndrome when used with serotonergic drugs.

Incorrect choices: Tapentadol is not an opioid antagonist as are naloxone, nalmefene, and naltrexone. It does not prevent the reuptake of acetylcholine.

REF: Specific Opioids (Tapentadol) | p. 68 OBJ: 6

1. The following statements are false of tramadol except which one?

a.	It binds to mu opioid receptors.
b.	It inhibits reuptake of serotonin and norepinephrine.
c.	It modifies ascending pain pathways.
d.	It causes mydriasis.
e.	Its analgesic efficacy is equivalent to that of codeine.

ANS: D

Correct: Mydriasis is pupillary dilation. As in opioids, tramadol causes miosis, or pinpoint pupils.

Incorrect choices: Tramadol does in fact bind mu opioid receptors, inhibits reuptake of serotonin and norepinephrine, and modifies ascending pain pathways. Its analgesic efficacy is equivalent to that of codeine.

REF: Specific Opioids (Tramadol) | p. 68 OBJ: 6

1. Dentists prescribed about _____% of all opioids prescribed in the United States in 2002.

a.	2
b.	12
c.	22
d.	32
e.	42

ANS: B

Correct: Dentists are second only to family practice physicians as the practitioners prescribing the highest number of immediate-release opioids in the United States in 2002. They accounted for 12.2% of all opioid prescribed. Analgesics are prescribed at a rate second only to antibiotics in a dental practice.

Incorrect choices: The other choices do not correctly represent the percentage of opioids prescribed by dentists in the United States in 2002.

REF: Dental Use of Opioids | p. 68 OBJ: 7

1. Which of the following types of pain medications is the best choice for management of most dental pain?

a.	Antidepressants
b.	Nonsteroidal anti-inflammatory drugs (NSAIDs)
c.	Aspirin
d.	Acetaminophen

ANS: B

Correct: The advent of the NSAIDs has produced a change in the use of the opioids in dental practice. Most dental pain can be better managed by the use of NSAIDs. In the patient in whom NSAIDs are contraindicated, the dentist has a wide range of opioids from which to choose.

Incorrect choices: Antidepressants are not the best choice for management of most dental pain although low doses of antidepressants may be used along with NSAIDs and muscle relaxants to treat TMD. Aspirin and acetaminophen are not the first choice for dental pain.

REF: Dental Use of Opioids | p. 68 OBJ: 7

MULTIPLE RESPONSE

1. Which of the following are classified as mixed opioid? (Select all that apply.)

a.	Morphine
b.	Pentazocine
c.	Naloxone
d.	Buprenorphine

ANS: B, D

Correct: Pentazocine is a mixed opioid classified as an agonist antagonist. Buprenorphine is a mixed opioid that is classified as a partial agonist.

Incorrect choices: Morphine is an opioid agonist. Naloxone is a morphine antagonist.

REF: Table 6-1: Classification of the Opioids by Receptor Action | p. 61

OBJ: 1

TRUE/FALSE

1. Morphine is stronger than oxycodone.

ANS: T

Correct: Morphine has greater efficacy (analgesic power) than oxycodone.

REF: Table 6-3: Selected Opioid Analgesics by Efficacy, Dosing Interval, Usual Doses, and Schedule | p. 62 OBJ: 4

1. Codeine activates the chemoreceptor trigger zone.

ANS: T

Correct: Codeine can cause nausea and vomiting by acting on this medullary structure.

REF: Adverse Reactions (Nausea and Emesis) | p. 63 OBJ: 2

1. Combining an opioid with a nonopioid analgesic produces an additive analgesic effect with fewer adverse reactions.

ANS: T

Correct: These agents work at two different levels on pain and produce an additive analgesic effect. In combination products, lower doses of each analgesic may be used, and a potential exists for a reduction in adverse reactions.

REF: Specific Opioids (Oxycodone) | p. 65 OBJ: 4

1. A patient who feels nauseated after taking codeine is allergic to it.

ANS: F

Correct: Nausea is a normal pharmacologic action of codeine on the chemoreceptor trigger zone in the brain.

REF: Adverse Reactions (Nausea and Emesis) | p. 63 OBJ: 2

1. Opioids are the first choice for the treatment of chronic pain, such as temporomandibular joint and muscle disorders.

ANS: T

Correct: Because of their dependence liability, opioids should not be the first choice for patients with chronic pain (unless they are terminally ill). The dentist should initiate therapy with an NSAID. Opioids should be considered if this fails. Only those dentists that are comfortable with prescribing chronic opioid therapy should treat patients with chronic orofacial pain.

REF: Chronic Dental Pain and Opioid Use | p. 69 OBJ: 7

Chapter 07: Antiinfective Agents

Haveles: Applied Pharmacology for the Dental Hygienist, 7th Edition

MULTIPLE CHOICE

1. Dental caries is caused by an infection with:

a.	Porphyromonas gingivalis.
b.	Eikenella corrodens.
c.	Streptococcus mutans.
d.	Fusobacterium.

ANS: C

Correct: Dental caries is produced by Streptococcus mutans. It is the first important dental infection of the newly erupting teeth of the young patient. The treatment of choice is prevention and involves the use of fluoridated water, local physical removal of bacterial plaque biofilm from teeth on a regular basis, and appropriately placed sealants.

Incorrect choices: Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Eikenella corrodens, Fusobacterium spp., and Campylobacter rectus are all periodontal microbes.

REF: Introduction | p. 70 OBJ: 1

1. Which of the following choices is the dental hygienist’s biggest dental problem in the adult patient?

a.	Caries
b.	Periodontal disease
c.	Localized dental infection
d.	Systemic dental infection

ANS: B

Correct: Periodontal disease is the dental hygienist’s biggest dental problem in the adult patient. Current research suggests that periodontal disease may be associated with coronary heart disease. With an increase in knowledge about antiinfective agents, the dental hygienist and dentist will be better able to understand and properly administer the appropriate drug therapy.

Incorrect choices: Use of fluoridated water, local physical removal of bacterial plaque biofilm from teeth on a regular basis, and sealants have reduced the rate of caries. While it certainly is true that local and systemic dental infections are of great concern, they are not the biggest problem in an adult patient for a dental hygienist to manage.

REF: Introduction | p. 70 OBJ: 1

1. If an infection is just beginning, the organisms most likely to be present are:

a.	gram-positive cocci.
b.	gram-negative cocci.
c.	gram-positive anaerobes.
d.	gram-negative anaerobes.

ANS: A

Correct: Gram-positive cocci are most likely to present if the infection is just beginning. After a short time, the gram-positive infection begins to include a variety of both gram-positive and gram-negative anaerobic organisms. With additional time and no treatment, the infection progresses until it consists of predominantly anaerobic flora.

Incorrect choices: Gram-negative and/or anaerobic organisms are not the earliest constituents of a dental infection.

REF: Dental Infection “Evolution” | p. 71 OBJ: 1

1. Which of the following agents is the drug of choice for an early dental infection unless the patient is allergic to it?

a.	Erythromycin
b.	Clindamycin
c.	Penicillin
d.	Metronidazole

ANS: C

Correct: Penicillin is the drug of choice unless the patient is allergic to it. Amoxicillin is most often used because it is less irritating to the stomach than other drugs and can be taken with food or milk.

Incorrect choices: In patients allergic to penicillin, alternatives might include erythromycin or clindamycin. When the infection is at the mixed stage, agents effective against either gram-positive or anaerobic organisms may be successful. Metronidazole is effective for anaerobic organisms.

REF: Dental Infection “Evolution” | p. 71 OBJ: 1

1. Which of the following antibiotics is associated with pseudomembranous colitis?

a.	Penicillin
b.	Erythromycin
c.	Clindamycin
d.	Metronidazole

ANS: C

Correct: Clindamycin is associated with pseudomembranous colitis. It is characterized by severe, persistent diarrhea and the passage of blood and mucus. It is caused by a toxin produced by the bacterium Clostridium difficile. It is associated with other antibiotics in addition to clindamycin such as tetracycline, ampicillin, and the cephalosporins.

Incorrect choices: Pseudomembranous colitis has historically been linked with an antibiotic other than penicillin, erythromycin, or metronidazole. It now is known to occur not only with a wide variety of antiinfective agents including cephalosporins and amoxicillin, but also in the absence of any antimicrobial agents.

REF: Clindamycin (Gastrointestinal Effects) | p. 82 OBJ: 4 | 5

1. An _____ agent is a chemical substance produced by a microorganism that has the capacity, in dilute solutions, to destroy or suppress the growth or multiplication of organisms or to suppress their action.

a.	antiinfective
b.	antibacterial
c.	antibiotic
d.	antimicrobial

ANS: C

Correct: An antibiotic is a chemical substance produced by a microorganism.

Incorrect choices: The difference among the terms antibiotic, antiinfective, and antibacterial is that antibiotics are produced by microorganisms, whereas the other agents may be developed in a chemistry laboratory and not from a living organism. This difference is largely ignored in general conversation, and antiinfectives are often called antibiotics.

REF: Definitions | p. 71 OBJ: 1

1. Which of the following antiinfective agents is bacteriostatic rather than bactericidal?

a.	Cephalosporins
b.	Metronidazole
c.	Penicillins
d.	Tetracyclines
e.	Vancomycin

ANS: D

Correct: Tetracyclines—chloramphenicol, spectinomycin, sulfonamides, and trimethoprim—are all bacteriostatic. Clindamycin and macrolides also are bacteriostatic, but may be bactericidal against some organisms at higher blood levels.

Incorrect choices: Aminoglycosides—bacitracin, cephalosporins, metronidazole, penicillins, polymyxin, quinolones, rifampin, and vancomycin—are all bactericidal antiinfective agents.

REF: Box 7-2: Classification of Antiinfective Agents: Bactericidal or Bacteriostatic | p. 72

OBJ: 1

1. The disease-producing power of the microorganism is called:

a.	resistance.
b.	superinfection.
c.	infection.
d.	virulence.

ANS: D

Correct: Virulence is the disease-producing power of the microorganism.

Incorrect choices: Resistance is the ability of an organism to be immune to the effects of an antiinfective agent. Superinfection is an opportunistic infection that arises as a consequence of treatment. Infection is an unchecked increase in the number of pathogenic bacteria in the body.

REF: Infection | p. 71 OBJ: 1

1. Superinfection is more often caused by _____-spectrum antibiotics and increases when taken for a _____ time period.

a.	narrow; shorter
b.	narrow; longer
c.	broad; shorter
d.	broad; longer

ANS: D

Correct: Superinfection is more often caused by broad-spectrum antibiotics and increases when taken for a longer time period. A reduction in the number of gram-positive and gram-negative bacteria may allow the overgrowth of the fungus Candida albicans.

Incorrect choices: A broad-spectrum antibiotic is more likely to alter the nature of the microbes. A sensitivity test can determine whether the organisms are sensitive or resistant to certain test antibiotics and assist in determining which antibiotic to use in difficult infections.

REF: General Adverse Reactions and Disadvantages Associated with Antiinfective Agents (Superinfection [Suprainfection]) | p. 74 OBJ: 3

1. The possibility of superinfection can be minimized by use of the _____ specific antiinfective agent, the _____ effective course of therapy, and adequate doses.

a.	least; shortest
b.	least; longest
c.	most; shortest
d.	most; longest

ANS: C

Correct: The most specific antiinfective agent and the shortest course of therapy are best.

Incorrect choices: The wider the spectrum of the antiinfective agent and the longer the agent is administered, the greater the chance of superinfection.

REF: General Adverse Reactions and Disadvantages Associated with Antiinfective Agents (Superinfection [Suprainfection]) | p. 74 OBJ: 3

1. Which of the following statements is true concerning infection and host resistance?

a.	Host resistance should be considered as having both local and systemic components.
b.	Drugs such as steroids are capable of reducing a patient’s immunity.
c.	Juvenile diabetes may reduce a patient’s immunity; however, insulin-dependent diabetes mellitus (IDDM) does not reduce immunity.
d.	Both a and b
e.	Both b and c

ANS: D

Correct: Host resistance should be considered as having both local and systemic components.

Drugs such as steroids are capable of reducing a patient’s immunity.

Incorrect choices: Diseases such as acquired immunodeficiency syndrome (AIDS) and IDDM may reduce a patient’s immunity and increase the chance of an infection.

REF: Infection | pp. 71-72 OBJ: 1

1. Which of the following statements is true concerning a culture and sensitivity test?

a.	An antibiotic disk with a zone around it shows sensitivity.
b.	An antibiotic disk with no zone around it shows sensitivity.
c.	Antibiotic therapy should not be initiated until the results of the test are available.
d.	One to two weeks are required before the results of this test are available.

ANS: A

Correct: A zone of inhibition around the disk shows the organism is sensitive to the agent. After the organism is identified, it is grown on culture medium. Observing whether the organisms are sensitive or resistant to certain test antibiotics assists in determining which antibiotic to use in difficult infections.

Incorrect choices: One to two days are required before the results of the test are available. Although antibiotic therapy can start before this time, it may be changed after the results are available. If clinical response has been adequate, the original antibiotic is often continued despite sensitivity results.

REF: Figure 7-1: Culture and Sensitivity | p. 76 OBJ: 1

1. Which of the following statements is true concerning antibiotic resistance?

a.	Natural resistance occurs when an organism that was previously sensitive to an antimicrobial agent develops resistance.
b.	An increase in the use of an antibiotic in a given population decreases the proportion of resistant organisms in that population.
c.	Bacterial resistance can occur by the transfer of deoxyribonucleic acid (DNA) genetic material from one organism to another.
d.	The transfer of genetic material from one organism to another may only occur among organism of the same species.

ANS: C

Correct: Bacterial resistance can occur by the transfer of DNA genetic material from one organism to another via transduction, transformation, or bacterial conjugation.

Incorrect choices: Natural resistance occurs when an organism has always been resistant to an antimicrobial agent because of the bacteria’s normal properties, such as lipid structure in the cell wall. Acquired resistance occurs when an organism that was previously sensitive to an antimicrobial agent develops resistance. An increase in the use of an antibiotic in a given population increases the proportion of resistant organisms in that population. The transfer of genetic material from one organism to another may occur among very different microorganisms, including transfer from nonpathogenic bacteria to pathogenic bacteria.

REF: Resistance | p. 72 OBJ: 1

1. Which of the following periodontal diseases is usually not treated with antimicrobials?

a.	Periodontal abscess
b.	Localized juvenile periodontitis
c.	Adult periodontitis
d.	Rapidly advancing periodontitis

ANS: C

Correct: No antimicrobial agents are usually required for treatment of adult periodontitis or acute necrotizing ulcerative gingivitis.

Incorrect choices: The drug of choice for periodontal abscess is penicillin VK, with tetracycline as an alternative. For localized juvenile periodontitis, either doxycycline or tetracycline are the drugs of choice with amoxicillin + metronidazole, or Augmentin as alternative drugs. Rapidly advancing periodontitis (RAP) may be treated with doxycycline, tetracycline, or metronidazole. Amoxicillin + metronidazole are the alternative drugs for treating RAP.

REF: Table 7-1: Antimicrobial Use in Dentistry | p. 73 OBJ: 2

1. Superinfection describes a(n):

a.	nonsystemic, superficial infection.
b.	exaggerated infection caused by treating a resistant pathogen.
c.	opportunistic infection that arises as a consequence of treatment.
d.	infection by multiple pathogens.

ANS: C

Correct: When antiinfectives disturb the normal flora of the body, the emergence of organisms unaffected by or resistant to the antibiotic used can occur.

Incorrect choices: Superinfection can be superficial or nonsuperficial. It is an infection that does not require treatment of a resistant pathogen to occur. Superinfection can be an infection by one or more pathogens.

REF: General Adverse Reactions and Disadvantages Associated with Antiinfective Agents (Superinfection [Suprainfection]) | p. 74 OBJ: 3

1. Antiinfective agents can potentiate the effect of oral anticoagulants by interfering with the production of vitamin:

a.	A.
b.	D.
c.	E.
d.	K.

ANS: D

Correct: Oral anticoagulants are vitamin K inhibitors; thus, interference with the production of vitamin K could increase the anticoagulant effect. Bacterial flora in the intestine produces most of the vitamin K in human bodies. Antiinfective agents reduce the bacterial flora that produce vitamin K. With the vitamin K reduced, the oral anticoagulant’s effect is increased.

Incorrect choices: Vitamins A, D, E, and K are fat-soluble vitamins. Vitamin A is necessary for normal growth and for maintaining the health and integrity of certain epithelial tissues. Vitamin D refers to both vitamin D₂, which is found in plants, and vitamin D₃, which is produced in the skin of mammals by sunlight. There are eight naturally occurring tocopherols with vitamin E activity. Alpha tocopherol is the most active. It is found in wheat, sunflower, cottonseed, and olive oils.

REF: General Adverse Reactions and Disadvantages Associated with Antiinfective Agents (Oral Anticoagulants) | p. 74 OBJ: 3

1. _____ has the highest incidence of gastrointestinal complaints of any of the antibiotics.

a.	Penicillin
b.	Erythromycin
c.	Clindamycin
d.	Cephalosporin

ANS: B

Correct: Erythromycin has the highest incidence of gastrointestinal complaints.

Incorrect choices: The penicillins and cephalosporins are associated with allergic reactions rather than gastrointestinal complaints. More serious gastrointestinal complaints, such as pseudomembranous colitis, which has been historically linked with clindamycin, are now known to occur not only with a wide variety of antiinfective agents, but also in the absence of any antimicrobial agents.

REF: General Adverse Reactions and Disadvantages Associated with Antiinfective Agents (Gastrointestinal Complaints) | p. 74 OBJ: 3

1. Which of the following antibiotics are not associated with any teratogenicity and are often used in pregnant women?

a.	Penicillin
b.	Tetracyclines
c.	Erythromycin
d.	Metronidazole
e.	Both a and c

ANS: E

Correct: Penicillin and erythromycin have not been associated with teratogenicity and are often used in pregnant women.

Incorrect choices: Tetracyclines are contraindicated during pregnancy because of their effect on developing teeth and skeleton. Metronidazole is not usually used during pregnancy, but exceptions exist.

REF: General Adverse Reactions and Disadvantages Associated with Antiinfective Agents (Pregnancy Considerations) | p. 74 OBJ: 3

1. Which of the following statements is true concerning the pharmacokinetics of penicillin?

a.	Penicillin may be administered orally, parenterally, or topically.
b.	Penicillin G is better absorbed orally than penicillin V; thus, penicillin G is used for administration of oral penicillin.
c.	Penicillin V and amoxicillin can be taken without regard to meals.
d.	Penicillin does not cross the placenta and will not appear in breast milk.

ANS: C

Correct: The highest blood levels are obtained if the patient takes the penicillin orally at least 1 hour before or 2 hours after meals, but penicillin V and amoxicillin can be taken without regard to meals.

Incorrect choices: Penicillin can be administered either orally or parenterally, but should not be applied topically because its allergenicity is greatest by that route. Penicillin V is better absorbed orally than penicillin G; thus, penicillin V is used for administration of oral penicillin. Penicillin crosses the placenta and appears in breast milk.

REF: Penicillins (Pharmacokinetics) | p. 75 OBJ: 4

1. Penicillinase inactivates the penicillin moiety by:

a.	sublimation.
b.	desiccation.
c.	cleaving the b-lactam ring.
d.	cleaving the S-containing thiazolidine ring.

ANS: C

Correct: The penicillins belong to the group of antibiotics known as b-lactam antibiotics. They are so named because the b-lactam ring is common to the molecular structure of all antibiotics in this group. Penicillinase inactivates the moiety by cleaving the b-lactam ring.

Incorrect choices: The other choices represent substances that do not cleave the b-lactam ring. Sublimation occurs when a substance goes from solid directly to gas without becoming a liquid. Desiccation is loss of moisture. The thiazolidine ring is part of the structure of penicillin. The b-lactam ring is fused to the five-member, S-containing thiazolidine ring.

REF: Penicillins (Resistance) | p. 76 OBJ: 4

1. Which of the following agents allows the use of amoxicillin to treat penicillinase-producing organisms?

a.	Clavulanic acid
b.	Divalent cations
c.	Corticosteroids
d.	Disulfiram

ANS: A

Correct: Clavulanic acid serves as an inhibitor, which allows the use of amoxicillin to treat penicillinase-producing organisms.

Incorrect choices: The other choices are not added to amoxicillin in order to treat penicillinase-producing organisms. A divalent cation is an atom that is missing two electrons. They reduce the intestinal absorption of tetracyclines by forming non-absorbable chelates of tetracycline with calcium, for example. Corticosteroids are used to reduce inflammation. Disulfiram is a drug used to treat persons with alcohol problems.

REF: Penicillins (Resistance) | p. 76 OBJ: 4

1. Some studies indicate that _____% of patients receiving penicillin will have an allergic reaction.

a.	0.05 to 0.10
b.	0.5 to 1
c.	5 to 10
d.	20 to 25

ANS: C

Correct: Some studies indicate that 5% to 10% of patients receiving penicillin will have an allergic reaction. Allergic reactions to oral penicillin are less common than with parenteral penicillin.

Incorrect choices: The other choices do not correctly express the results indicated by studies regarding the frequency of allergic reaction to the administration of penicillin.

REF: Penicillins (Allergy and Hypersensitivity) | p. 76 OBJ: 4

1. Which of the following statements is true regarding penicillin allergy?

a.	Allergic reactions with oral penicillin are more common than with parenteral penicillin.
b.	Anaphylactic reactions are more frequent in patients pretreated with b-blockers and subsequently given oral penicillin.
c.	The treatment of anaphylaxis caused by penicillin is the immediate administration of corticosteroids.
d.	Estimates indicate that 10,000 to 30,000 deaths occur annually in the United States because of an allergic reaction to penicillin.

ANS: B

Correct: Anaphylactic reactions are more frequent in patients pretreated with b-blockers and subsequently given oral penicillin. Anaphylactic reactions in these patients have been reported to be difficult to treat.

Incorrect choices: Allergic reactions with parenteral penicillin are more common than with oral penicillin. The treatment of anaphylaxis caused by penicillin is the immediate administration of parenteral epinephrine. An estimated 100 to 300 deaths occur annually in the United States because of an allergic reaction to penicillin.

REF: Penicillins (Allergy and Hypersensitivity) | p. 76 OBJ: 4

1. Which of the following salts of penicillin G produces the most rapid and highest blood level?

a.	Potassium salt given intravenously
b.	Potassium salt given intramuscularly
c.	Benzathine salt given intramuscularly
d.	Procaine salt intramuscularly

ANS: A

Correct: The potassium salt given intravenously produces the most rapid and highest blood level. The penicillin’s duration of action is inversely proportional to the solubility of the penicillin form: the least soluble is the longest acting.

Incorrect choices: The benzathine salt given intramuscularly produces the lowest and most sustained blood level. The potassium and procaine salts, given intramuscularly, produce intermediate blood levels and durations of action.

REF: Penicillins (Penicillin G) | p. 77 OBJ: 4

1. The usual adult dose of penicillin V for treatment of an infection is:

a.	250 mg twice a day (bid).
b.	250 mg four times a day (qid).
c.	500 mg twice a day (bid).
d.	500 mg four times a day (qid).

ANS: D

Correct: The usual adult dose is 500 mg qid for the treatment of an infection for a minimum of 5 days and preferably for 7 to 10 days.

Incorrect choices: The usual adult dose of penicillin for treating an infection is not 250 mg. Penicillin is not usually administered twice a day (bid) in order to treat an infection.

REF: Penicillins (Penicillin V) | p. 77 OBJ: 4

1. Which of the following statements is true regarding penicillinase-resistant penicillins?

a.	Penicillinase-resistant penicillins should be reserved for use against only penicillinase-producing staphylococci.
b.	Penicillinase-resistant penicillins are more effective against penicillin G–sensitive organisms when compared with penicillin G.
c.	Penicillinase-resistant penicillins produce fewer side effects when compared with penicillin G.
d.	Patients allergic to penicillin are not also allergic to the penicillinase-resistant penicillins.

ANS: A

Correct: Penicillinase-resistant penicillins should be reserved for use against only penicillinase-producing staphylococci.

Incorrect choices: The penicillinase-resistant penicillins are less effective against penicillin G–sensitive organisms when compared with penicillin G. Penicillinase-resistant penicillins produce more side effects when compared with penicillin G. Patients allergic to penicillin are also allergic to the penicillinase-resistant penicillins.

REF: Penicillins (Penicillinase-Resistant Penicillins) | p. 77 OBJ: 4

1. Which drug should be used before oral prophylaxis prior to dental treatment for a patient who has rheumatic heart disease with no known drug allergies?

a.	Amoxicillin
b.	Tetracycline
c.	Clindamycin
d.	Erythromycin
e.	None of the above

ANS: E

Correct: The current guidelines for prevention of infective endocarditis from the American Heart Association (2008) do not recommend oral immunoprophylaxis before dental treatment for a patient with a history of rheumatic heart disease. Specific indications for oral immunoprophylaxis may be found on the American Heart Association Website.

Incorrect choices: A history of rheumatic heart disease is no longer considered an indication for oral immunoprophylaxis. If the patient does have one of the currently recommended indications amoxicillin is the standard treatment of choice if no complicating factors are present, such as allergy to penicillins. Tetracycline is never indicated for infective endocarditis prophylaxis just before dental procedures because it is likely to produce bacteremia. Clindamycin is a recommended alternative to amoxicillin if penicillin allergies exist, and erythromycin analogues azithromycin and clarithromycin are also good alternatives.

REF: Box 7-6: Cardiac Conditions Associated with the Highest Risk of Adverse Outcomes from Endocarditis | p. 90 OBJ: 4

1. _____ is the drug of choice for prophylaxis to prevent bacterial endocarditis before a dental procedure.

a.	Penicillin G
b.	Penicillin V
c.	Ampicillin
d.	Amoxicillin

ANS: D

Correct: Amoxicillin is the drug of choice. Amoxicillin is also used to treat upper respiratory tract infections, urinary tract infections, and meningitis. Otitis media in children is often treated with amoxicillin. It has had some use in the management of certain periodontal conditions.

Incorrect choices: Penicillin G, penicillin V, and ampicillin are not used for prophylaxis to prevent bacterial endocarditis prior to a dental procedure.

REF: Penicillins (Ampicillins) | p. 77 OBJ: 4

1. Which of the following antibiotics is available mixed with clavulanic acid?

a.	Ampicillin
b.	Amoxicillin
c.	Carbenicillin
d.	Azithromycin

ANS: B

Correct: Augmentin is amoxicillin mixed with clavulanic acid. Clavulanic acid combines with and inhibits the b-lactamases produced by bacteria. Therefore the amoxicillin is protected from enzymatic inactivation. This combination can be taken with penicillinase-producing organisms. It has had some use in the management of certain periodontal conditions.

Incorrect choices: The other antibiotics are not mixed with clavulanic acid.

REF: Penicillins (Ampicillins) | p. 77 OBJ: 4

1. Clavulanic acid is:

a.	a bacteriostatic antibiotic.
b.	a bactericidal antibiotic.
c.	a b-lactamase inhibitor.
d.	both a and c.
e.	both b and c.

ANS: C

Correct: Clavulanic acid is a penicillinase (b-lactamase) inhibitor. It inhibits the ability of bacteria to break down b-lactam–containing antibiotics.

Incorrect choices: Clavulanic acid is not an antibiotic.

REF: Penicillins (Ampicillins) | p. 77 OBJ: 4

1. Clavulanic acid is used to fight infections with which of the following resistance mechanisms?

a.	Decreased permeability to the agent
b.	Production of drug-inactivating enzymes
c.	Alteration in the site of action
d.	Any of the above

ANS: B

Correct: Clavulanic acid is an inhibitor of penicillinase (b-lactamase), an enzyme produced by bacteria that can inactivate b-lactam–containing enzymes.

Incorrect choices: Clavulanic acid is not effective in circumventing resistance mechanisms.

REF: Penicillins (Ampicillins) | p. 77 OBJ: 4

1. Which of the following statements is true of the cephalosporins?

a.	They are active against gram-positive but not gram-negative organisms.
b.	Those available for oral use are susceptible to penicillinase.
c.	They are bacteriostatic.
d.	Their mechanism of action is inhibition of cell wall synthesis.

ANS: D

Correct: The mechanism of action of the cephalosporins is like that of the penicillins: inhibition of cell wall synthesis.

Incorrect choices: Cephalosporins are active against a wide variety of both gram-positive and gram-negative organisms. Those available for oral use are relatively acid stable and highly resistant to penicillinase. The cephalosporins, which are bactericidal, are active against most gram-positive cocci, penicillinase-producing staphylococci, and some gram-negative bacteria.

REF: Cephalosporins (Mechanism of Action) | p. 78 OBJ: 4

1. Large doses of cephalosporins often produce a Coombs’ reaction, which means:

a.	high blood pressure is exacerbated.
b.	the immune mechanism is attacking the patient’s own red blood cells.
c.	degeneration of neural glial cells occurs.
d.	nephritis of the kidneys occurs.

ANS: B

Correct: The Coombs’ reaction means the immune mechanism is attacking the patient’s own red blood cells, which can lead to a significant degree of hemolysis.

Incorrect choices: The other choices do not properly define a Coombs’ reaction.

REF: Cephalosporins (Allergy) | p. 78 OBJ: 4

1. A cephalosporin would be most closely related to which of the following agents?

a.	Penicillin VK
b.	Clarithromycin
c.	Ciprofloxacin
d.	Doxycycline
e.	Clindamycin

ANS: A

Correct: Cephalosporins and penicillins have similarities in structure; they are both b-lactam antibiotics. They also have the same mechanism of action.

Incorrect choices: Clarithromycin is a macrolide, ciprofloxacin is a fluoroquinolone, doxycycline is a tetracycline, and clindamycin is an analogue of lincomycin, not structurally related to any others. Its mechanism of action is similar to that of macrolides.

REF: Cephalosporins | p. 77 OBJ: 4

1. Which of these agents do not inhibit bacterial cell-wall synthesis?

a.	Vancomycin
b.	Erythromycin
c.	Penicillin G
d.	Cefazolin

ANS: B

Correct: Erythromycin is a bacteriostatic agent that inhibits bacterial protein synthesis.

Incorrect choices: Vancomycin, penicillin G, and cefazolin all inhibit cell-wall synthesis. They are bactericidal.

REF: Macrolides (Mechanism and Spectrum) | p. 78 OBJ: 4

1. Which of the following statements is true concerning the pharmacokinetics of erythromycin?

a.	Erythromycin is broken down in gastric fluid and absorbed through the stomach wall.
b.	Erythromycin is not available in a topical preparation because of allergenicity.
c.	Erythromycin is available in oral but not injectable forms.
d.	Erythromycin should be administered 2 hours before or 2 hours after meals.

ANS: D

Correct: Erythromycin should be administered 2 hours before or 2 hours after meals. Although food reduces the absorption of erythromycin, administering it with food may be necessary to minimize its adverse gastrointestinal effects.

Incorrect choices: Because erythromycin is broken down in gastric fluid, it is formulated as an enteric-coated tablet, capsule, or insoluble ester to reduce degradation by stomach acid. Erythromycin is administered orally as tablets and capsules, oral suspensions in intravenous and intramuscular forms, and in topical preparations.

REF: Macrolides (Pharmacokinetics) | p. 79 OBJ: 4

1. Which of the following conditions is the most common adverse reaction from the administration of erythromycin?

a.	Anaphylaxis
b.	Skin rash
c.	Gastrointestinal effects
d.	Miosis

ANS: C

Correct: The side effects most often associated with erythromycin administration are gastrointestinal and include stomatitis, abdominal cramps, nausea, vomiting, and diarrhea. In one study, at least one gastrointestinal side effect occurred in an average of approximately 50% of patients, with approximately 20% discontinuing their medication because of side effects.

Incorrect choices: The other choices do not represent the most common adverse reaction for the administration of erythromycin.

REF: Macrolides (Adverse Reactions) | p. 79 OBJ: 4

1. Which of the following agents is the drug of first choice against infections caused by aerobic microorganisms in penicillin-allergic patients?

a.	Metronidazole
b.	Erythromycin
c.	Doxycycline
d.	Clindamycin

ANS: B

Correct: Because erythromycin is active against essentially the same aerobic microorganisms as penicillin, it is the drug of first choice against these infections in penicillin-allergic patients. Erythromycin is not effective against the anaerobic Bacteroides species implicated in many dental infections.

Incorrect choices: The other choices are not the drug of first choice against aerobic infections in penicillin-allergic patients.

REF: Macrolides (Uses) | p. 79 OBJ: 4

1. Azithromycin and clarithromycin:

a.	cause lysis of the bacterial cell wall.
b.	are not effective against anaerobes.
c.	have a higher incidence of adverse reactions than erythromycin.
d.	may be used as alternative antibiotics for the prophylaxis of endocarditis and prosthetic joint infections.

ANS: D

Correct: These macrolides can be used as alternative antibiotics when amoxicillin and clindamycin cannot be used for the prophylaxis of endocarditis and prosthetic joint infections.

Incorrect choices: Azithromycin and clarithromycin inhibit RNA-dependent protein synthesis by binding to the 50S ribosomal subunit. In contrast to erythromycin, azithromycin and clarithromycin have variable action against some anaerobes. The incidence of adverse reactions is lower with azithromycin and clarithromycin compared with erythromycin.

REF: Macrolides (Azithromycin and Clarithromycin) | p. 79 OBJ: 4

1. Which of the following statements is true of the tetracyclines?

a.	They are bactericidal.
b.	Tetracyclines interfere with the synthesis of bacterial protein by binding at the 50S subunit of bacterial ribosomes.
c.	In the study of sensitivity or organisms isolated from dental infections, one-fifth to two-fifths of Staphylococcus aureus (S. aureus) were found to be resistant to tetracycline.
d.	Tetracyclines are not prone to enterohepatic circulation.

ANS: C

Correct: In the study of sensitivity or organisms isolated from dental infections, one-fifth to two-fifths of S. aureus and one-fifth to three-fifths of Streptococcus viridans were found to be resistant to tetracycline.

Incorrect choices: The tetracyclines are bacteriostatic and interfere with the synthesis of bacterial proteins by binding at the 30S subunit of bacterial ribosomes. Enterohepatic circulation prolongs the action of the tetracyclines after they have been discontinued.

REF: Tetracyclines (Spectrum) | p. 80 OBJ: 4

1. Tetracyclines should not be used in children younger than _____ years of age.

a.	6
b.	9
c.	12
d.	15

ANS: B

Correct: If tetracycline is administered between 2 months and 7 or 8 years of age, the permanent teeth will be affected. The mechanism involves the deposition of tetracycline in the enamel of the forming teeth. These stains are permanent and darken with age and exposure to light. They begin as a yellow fluorescence and progress with time to brown.

Incorrect choices: The other choices do not represent the correct minimum age for administration of tetracyclines. Adult teeth start to form about 6 years prior to eruption and the concern has to do with staining of adult teeth.

REF: Tetracyclines (Effects on Teeth and Bones) | pp. 80-81 OBJ: 4

1. _____ can cause black pigmentation of mandibular and maxillary alveolar bone and the hard palate.

a.	Penicillin V
b.	Erythromycin
c.	Minocycline
d.	Clindamycin

ANS: C

Correct: With discontinuation of minocycline, the pigmentation becomes less intense but is usually not completely reversible. When viewed through the mucosa, the pigment appears bluish. Other cases of oral pigmentation have been said to involve the crowns of the permanent teeth and the gingival mucosa. The incidence of this oral pigmentation in adults is 10% after 1 year and 20% after 4 years of therapy.

Incorrect choices: The other choices are not antibiotics that are associated with black pigmentation of mandibular and maxillary alveolar bone and the hard palate.

REF: Tetracyclines (Effects on Teeth and Bones) | p. 81 OBJ: 4

1. Which of the following antibiotics is associated with photosensitivity?

a.	Erythromycin
b.	Tetracycline
c.	Metronidazole
d.	Aminoglycosides (e.g., streptomycin)

ANS: B

Correct: Patients taking tetracyclines who are exposed to sunlight sometimes react with exaggerated sunburn. Patients should be told to use a sunscreen before exposure to the sun.

Incorrect choices: The other antibiotics are not associated with photosensitivity.

REF: Tetracyclines (Photosensitivity) | p. 81 OBJ: 4

1. Which of the following statements is true concerning clindamycin?

a.	Clindamycin is distributed throughout most body tissues, including bone.
b.	Cross-resistance between clindamycin and erythromycin is often noted.
c.	The indications for treatment with clindamycin are limited to a number of infections caused by aerobic organisms.
d.	Both a and b are true.
e.	Both b and c are true.

ANS: D

Correct: Clindamycin is distributed throughout most body tissues, including bone but not to cerebrospinal fluid. Cross-resistance between clindamycin and erythromycin is often noted. An antagonistic relationship has been observed between clindamycin and erythromycin because of competition for the same binding site (50S subunit) on the bacteria.

Incorrect choices: The antibacterial spectrum of clindamycin includes many gram-positive organisms and some gram-negative organisms. Similar to erythromycin, clindamycin’s activity includes S. pyogenes and S. viridans, pneumococci, and S. aureus. In contrast to erythromycin, clindamycin is very active against several anaerobes, including Bacteroides fragilis and Bacteroides melaninogenicus, Fusobacterium species, Peptostreptococcus and Peptococcus species, and Actinomyces israelii.

REF: Clindamycin (Pharmacokinetics) | p. 82 | Clindamycin (Spectrum) | p. 82

OBJ: 4

1. Which of the following agents is most closely associated with the development of pseudomembranous colitis as a toxicity that limits its general use?

a.	Erythromycin
b.	Clindamycin
c.	Penicillin VK
d.	Metronidazole

ANS: B

Correct: A historical association exists between clindamycin use and pseudomembranous colitis, which limits its use relative to other eligible antibacterial agents.

Incorrect choices: Pseudomembranous colitis is a possible consequence related to the use of other antibacterials in addition to the antibiotic most closely associated. Other antibiotics include tetracycline, ampicillin, and the cephalosporins.

REF: Clindamycin (Gastrointestinal Effects) | p. 82 OBJ: 4

1. Which of the following is the most common adverse reaction to administration of metronidazole?

a.	Central nervous system effects
b.	Gastrointestinal effects
c.	Renal toxicity
d.	Oral effects

ANS: B

Correct: Metronidazole’s most common adverse reactions involve the gastrointestinal tract. This side effect occurs in 12% of patients taking metronidazole. It includes nausea, anorexia, diarrhea, and vomiting. Epigastric distress and abdominal cramping have also been reported.

Incorrect choices: The other choices do not represent the most common adverse reaction to the administration of metronidazole.

REF: Metronidazole (Gastrointestinal Effects) | p. 83 OBJ: 4

1. Administration of metronidazole for dental infections during pregnancy is:

a.	contraindicated.
b.	permitted only during the second trimester.
c.	permitted during the last half of pregnancy.
d.	permitted without restriction.

ANS: A

Correct: Metronidazole is contraindicated during pregnancy. Nursing mothers should not be given metronidazole unless milk is expressed and discarded beginning when the metronidazole is taken and continuing for 48 hours after discontinuing the drug.

Incorrect choices: The other choices are not correct. Metronidazole is in Food and Drug Administration (FDA) pregnancy category B because administration to pregnant mice caused fetal toxicity.

REF: Metronidazole (Other Effects) | p. 83 OBJ: 4

1. _____ is associated with a severe drug interaction with alcohol.

a.	Erythromycin
b.	Tetracycline
c.	Metronidazole
d.	Aminoglycosides (e.g., streptomycin)

ANS: C

Correct: Metronidazole is unique among antiinfectives in that it causes a disulfiram-like reaction with alcohol. Disulfiram is used to treat persons with alcohol problems. Symptoms include nausea, abdominal cramps, flushing, vomiting, or headache. Alcohol should be avoided during administration of metronidazole and for 1 day after therapy has ended.

Incorrect choices: The other antibiotics are not associated with a disulfiram-like reaction.

REF: Metronidazole (Drug Interactions) | p. 83 OBJ: 4

1. Which of the following statements is true of vancomycin?

a.	Vancomycin is related to the cephalosporins.
b.	Vancomycin is usually administered only intravenously for a systemic effect.
c.	Vancomycin is bacteriostatic.
d.	Vancomycin has a broad spectrum of action against a wide variety of gram-positive and gram-negative organisms.

ANS: B

Correct: Because vancomycin has very poor gastrointestinal absorption and causes irritation when used intramuscularly, it is usually administered only intravenously for a systemic effect.

Incorrect choices: Vancomycin is unrelated to any other antibiotic currently marketed. It is bactericidal and has a narrow spectrum of activity against many gram-positive cocci, including both staphylococci and streptococci.

REF: Antimicrobial Agents for Nondental Use (Vancomycin) | p. 84

OBJ: 5

1. An erythematous rash on the face and upper body known as red man syndrome is associated with use of which of the following antimicrobial agents?

a.	Augmentin
b.	Metronidazole
c.	Vancomycin
d.	Chloramphenicol

ANS: C

Correct: Red man syndrome is an adverse reaction noted with intravenous use of vancomycin. Hypotension accompanied by flushing, chills, and drug fever is also associated with vancomycin.

Incorrect choices: The other choices are not associated with red man syndrome.

REF: Antimicrobial Agents for Nondental Use (Adverse Reactions) | p. 84

OBJ: 5

1. Aminoglycosides:

a.	are bacteriostatic.
b.	are used primarily to treat aerobic gram-negative infections when other agents are ineffective.
c.	are indicated for stage 1 infections.
d.	inhibit cell wall synthesis.

ANS: B

Correct: Aminoglycosides are used primarily to treat aerobic gram-negative infections when other agents are ineffective. They have little action against gram-positive anaerobic or facultative bacteria.

Incorrect choices: The aminoglycosides are bactericidal. Because they have little action against gram-positive anaerobic or facultative bacteria, aminoglycosides would not be the drug of choice for treatment of a stage 1 infection. Rather, the drug of choice in patients without a penicillin allergy is penicillin V 500 mg every 6 hours for 5 to 7 days. Aminoglycosides appear to inhibit protein synthesis and to act directly on the 30S subunit of the ribosome.

REF: Antimicrobial Agents for Nondental Use (Spectrum) | p. 85

OBJ: 5

1. Which of the following antimicrobial agents is associated with ototoxicity?

a.	Vancomycin
b.	Aminoglycosides
c.	Nitrofurantoin
d.	Quinolones

ANS: B

Correct: The aminoglycosides are toxic to the eighth cranial nerve, which can lead to auditory and vestibular disturbances, or ototoxicity. Patients may have difficulty maintaining equilibrium and can develop vertigo. Hearing impairment and deafness, which can be permanent, have resulted from the administration of these agents. The side effect is more common in patients with renal failure because the drug accumulates in the body.

REF: Antimicrobial Agents for Nondental Use (Adverse Reactions) | p. 85

OBJ: 5

1. Oral-cavity infections are generally understood to advance through three stages. The three stages are (1) mixed aerobic and anaerobic infection, (2) aerobic infection, and (3) anaerobic infection. In what order do these stages occur?

a.	1, 2, 3
b.	1, 3, 2
c.	2, 1, 3
d.	3, 1, 2
e.	3, 2, 1

ANS: C

Correct: The organisms responsible for a dental infection are primarily aerobic gram-positive cocci, such as Streptococcus viridans. After a short time, the gram-positive infection begins to include a variety of both gram-positive and gram-negative anaerobic organisms, such as Peptostreptococcus (Peptococcus) and Bacteroides (Porphyromonas and Prevotella species). At this point the infection is termed a mixed infection. Over time, the proportion of organisms that are anaerobic increases.

Incorrect choices: The other choices do not correctly depict the sequence of development of an oral cavity infection.

REF: Rational Use of Antiinfective Agents in Dentistry (Stages of Infection) | p. 83

OBJ: 6

1. Which of the following antibiotics would be the best choice for treatment of an acute abscess or cellulitis in a patient who is not allergic to penicillin?

a.	Metronidazole
b.	Erythromycin
c.	Amoxicillin
d.	Clindamycin

ANS: C

Correct: Acute abscess and cellulitis are primarily the result of gram-positive organisms. The drug of choice in patients without a penicillin allergy is penicillin or amoxicillin. The patient must complete the full course of therapy in order to ensure that all of the bacteria are killed off and to help reduce the chance for resistance.

Incorrect choices: The other choices do not represent the first drug of choice.

REF: Rational Use of Antiinfective Agents in Dentistry (Stage 1) | p. 84

OBJ: 6

1. When a patient with a stage 1 infection is allergic to penicillin V, the best alternative would be:

a.	penicillin G or ampicillin.
b.	erythromycin ethylsuccinate or clindamycin.
c.	tetracycline or metronidazole.
d.	vancomycin.

ANS: B

Correct: For a patient with a stage 1 infection who is allergic to penicillin, erythromycin ethylsuccinate or clindamycin may be used.

Incorrect choices: The other antibiotics are not the best choice to use for this circumstance.

REF: Rational Use of Antiinfective Agents in Dentistry (Stage 1) | p. 84

OBJ: 6

1. Which of the following antibiotics would be the best choice to attack the anaerobes in a stage 2 infection?

a.	Clindamycin or metronidazole
b.	Ampicillin or amoxicillin
c.	Amoxicillin or augmentin
d.	Ciprofloxacin

ANS: A

Correct: An antiinfective with good anaerobic coverage is needed. The two antibiotics with the most anaerobic coverage are clindamycin and metronidazole. Penicillin V also has anaerobic coverage.

Incorrect choices: The remaining choices do not have a good anaerobic spectrum of action.

REF: Rational Use of Antiinfective Agents in Dentistry (Stage 2) | p. 84

OBJ: 6

1. The sulfonamides competitively inhibit the bacterial enzyme that incorporates para-aminobenzoic acid (PABA) into an immediate precursor of:

a.	biotin.
b.	thiamine.
c.	folic acid.
d.	riboflavin.

ANS: C

Correct: Because of their structural similarity to PABA, the sulfonamides competitively inhibit dihydropteroate synthetase, the bacterial enzyme that incorporates PABA into dihydrofolic acid, an immediate precursor of folic acid. Unlike humans, many bacteria are unable to use preformed folic acid, which is essential for their growth. They must synthesize folic acid from PABA.

Incorrect choices: The other choices are not derived from para-aminobenzoic acid.

REF: Antimicrobial Agents for Nondental Use (Mechanism of Action) | p. 85

OBJ: 5

1. The most common adverse reaction to the sulfonamides is:

a.	liver damage.
b.	suppressed renal function.
c.	an allergic skin reaction.
d.	blood dyscrasias.

ANS: C

Correct: The most common adverse reaction to the sulfonamides is an allergic skin reaction. These reactions may manifest as rash, urticaria, pruritus, fever, a fatal exfoliative dermatitis, or periarteritis nodosa.

Incorrect choices: Liver damage, depressed renal function, blood dyscrasias, and precipitation of lupus erythematosus are seen less often.

REF: Antimicrobial Agents for Nondental Use (Adverse Reactions) | p. 85

OBJ: 5

1. Which of the following agents is bacteriostatic in action?

a.	Amoxicillin
b.	Streptomycin
c.	Vancomycin
d.	Trimethoprim

ANS: D

Correct: Antibacterials can be bacteriostatic or bactericidal. Trimethoprim is bacteriostatic—it inhibits the growth of bacteria.

Incorrect choices: Amoxicillin, streptomycin, and vancomycin are all bactericidal agents. They kill bacteria.

REF: Antimicrobial Agents for Nondental Use (Sulfamethoxazole-Trimethoprim) | pp. 85-86

OBJ: 5

1. Which of the following statements is true regarding nitrofurantoin?

a.	Nitrofurantoin has a narrow spectrum of action against anaerobic bacteria.
b.	Nitrofurantoin is bactericidal.
c.	Nitrofurantoin is associated with red man syndrome.
d.	Nitrofurantoin can cause a brownish discoloration of urine.

ANS: D

Correct: The most common adverse reactions are nausea, vomiting, and diarrhea, but taking the drug with food decreases these effects. Nitrofurantoin can cause a brownish discoloration of urine.

Incorrect choices: Nitrofurantoin possesses a wide antibacterial spectrum including both gram-positive and gram-negative bacteria. It is bacteriostatic against many common urinary tract pathogens, including Escherichia coli. Vancomycin is associated with red man syndrome.

REF: Antimicrobial Agents for Nondental Use (Nitrofurantoin) | p. 86

OBJ: 5

1. _____ are the first orally active agents against certain Pseudomonas species.

a.	Aminoglycosides
b.	Sulfonamides
c.	Quinolones
d.	Tetracyclines

ANS: C

Correct: Quinolones are the first orally active agents against certain Pseudomonas species. They are bactericidal against most gram-negative organisms and many gram-positive organisms.

Incorrect choices: The other choices do not represent the first orally active agent against certain species of Pseudomonas.

REF: Antimicrobial Agents for Nondental Use (Quinolones [Fluoroquinolones]) | p. 86

OBJ: 5

1. Quinolones:

a.	must be administered parenterally and cannot be taken orally.
b.	have no use in dentistry.
c.	are bactericidal against most gram-negative organisms and many gram-positive organisms.
d.	have cross-resistance with many other antimicrobial agents.

ANS: C

Correct: Quinolones are bactericidal against most gram-negative organisms and many gram-positive organisms.

Incorrect choices: The quinolones are orally effective. This group may have potential use in dentistry because of their spectrum of action. No cross-resistance occurs with other antimicrobial agents.

REF: Antimicrobial Agents for Nondental Use (Quinolones [Fluoroquinolones]) | p. 86

OBJ: 5

1. Which agent inhibits DNA gyrase?

a.	Penicillin G
b.	Erythromycin
c.	Metronidazole
d.	Ciprofloxacin

ANS: D

Correct: Ciprofloxacin. The mechanism of action of the quinolones is unique and involves antagonism of the A subunit of DNA gyrase; the enzyme is involved in DNA synthesis.

Incorrect choices: Penicillin G inhibits cell wall synthesis, erythromycin inhibits protein synthesis, and metronidazole disrupts DNA’s helical structure independent of DNA gyrase.

REF: Antimicrobial Agents for Nondental Use (Quinolones [Fluoroquinolones]) | p. 86

OBJ: 5

1. Unlike other antiinfective agents, an additive action may result when _____ is combined with other antimicrobial agents.

a.	vancomycin
b.	chloramphenicol
c.	nitrofurantoin
d.	ciprofloxacin

ANS: D

Correct: An additive action may result when ciprofloxacin is combined with other antimicrobial agents. The emergence of organisms resistant to the fluoroquinolones and the cross-resistance among the fluoroquinolones is increasing. Use of fluoroquinolones in chickens may be partially responsible for increasing resistance.

Incorrect choices: The other choices do not have an additive action when combined with other antimicrobial agents.

REF: Antimicrobial Agents for Nondental Use (Spectrum) | p. 86

OBJ: 5

1. The drug whose future use may include organisms found in periodontal disease is:

a.	ofloxacin.
b.	sulfamethoxazole.
c.	macrodantin.
d.	streptomycin.

ANS: A

Correct: Ofloxacin’s spectrum of action most closely parallels the spectrum of microbes found in dental infections.

Incorrect choices: Sulfa drugs have no use in dentistry. Macrodantin is used for urinary tract infections (UTIs). Streptomycin was formerly used prophylactically for heart valve replacement; however, orally active agents are now recommended.

REF: Antimicrobial Agents for Nondental Use (Uses) | p. 77 OBJ: 5

1. Rupture of the Achilles tendon is associated with the use of:

a.	tetracyclines.
b.	quinolones.
c.	rifampin.
d.	mupirocin.

ANS: B

Correct: An unusual reaction affecting the Achilles tendon has become fairly common in patients taking quinolones. These agents can produce tendonitis or tendon rupture in the Achilles tendon. In 2008, the FDA issued a boxed warning alerting patients to the serious risk of tendon damage and rupture. In 2013, the FDA strengthened its warning regarding the risk of sudden, serious, and potentially permanent peripheral neuropathy.

Incorrect choices: These choices are not associated with rupture of the Achilles tendon.

REF: Antimicrobial Agents for Nondental Use (Adverse Reactions) | p. 86

OBJ: 5

1. Which of the following combinations of three drugs are administered concurrently in all active cases of tuberculosis (TB)?

a.	Pyrazinamide (PZA), rifapentine, and Rifater
b.	Isoniazid (INH), rifampin, and pyrazinamide
c.	Ethambutol, isoniazid (INH), and Rifater
d.	Rifampin, PZA, and streptomycin

ANS: B

Correct: INH, rifampin, and PZA are combined for the treatment of pulmonary TB. INH and rifampin are continued every day for 9 to 12 months. PZA is continued for 2 months. With susceptible organisms, a patient, if compliant, usually becomes noninfective within 2 to 3 weeks.

Incorrect choices: These choices do not represent the combination of three drugs that are administered in active cases of tuberculosis.

REF: Antituberculosis Agents | p. 87 OBJ: 7

1. If a person with active TB seeks oral health care:

a.	use standard precautions and treat him or her just as everyone else is treated.
b.	schedule him or her as the last patient of the day.
c.	contact that person’s physician and delay health care until the disease is no longer in the active state.
d.	refer the patient to a hospital with a dental suite for treatment.

ANS: C

Correct: Contact that person’s physician and delay health care until the disease is no longer in the active state. This person should be in the dental office only for evaluation of his or her dental condition and in order to make a referral.

Incorrect choices: These choices do not represent Centers for Disease Control (CDC) recommendations for management of a patient with active tuberculosis.

REF: Antituberculosis Agents | p. 87 OBJ: 7

1. Antibiotic prophylaxis to prevent endocarditis is considered reasonable for which of the following dental procedures?

a.	Oral radiographs
b.	Routine anesthetic injections through uninfected tissues
c.	Routine prophylaxis
d.	Shedding of deciduous teeth

ANS: C

Correct: Antibiotic prophylaxis is considered reasonable for all dental procedures that involve manipulation of gingival tissue or the periapical region of the teeth or perforation of the oral mucosa.

Incorrect choices: Antibiotic prophylaxis is not necessary for routine anesthetic injections through uninfected tissues, oral radiographs, placement of removable prosthodontic or orthodontic appliances, adjustment of orthodontic appliances, placement of orthodontic brackets, shedding of deciduous teeth, and bleeding from trauma to the lips or oral mucosa.

REF: Box 7-5: Dental Procedures for Which Endocarditis Prophylaxis is Reasonable for Patients with Specific Cardiac Conditions | p. 89 OBJ: 7

1. Infective endocarditis prophylaxis with an antiinfective is indicated for patients who have had:

a.	coronary artery bypass surgery.
b.	a prosthetic heart valve.
c.	functional murmur.
d.	a cardiac pacemaker.

ANS: B

Correct: Patients with prosthetic heart valves constitute a population at risk for developing infective endocarditis.

Incorrect choices: Coronary artery bypass surgery, functional murmur, and cardiac pacemaker are all conditions that most clinicians believe do not require prophylactic antibiotic coverage.

REF: Antibiotic Prophylaxis Used in Dentistry (Cardiac Conditions) | p. 89

OBJ: 7

1. The standard antibiotic drug regimen prior to dental procedures requiring immunoprophylaxis in a patient with no allergies to penicillin or amoxicillin is _____ g of amoxicillin _____ hour(s) before the procedure.

a.	1; 1
b.	1; 2
c.	2; 1
d.	2; 2

ANS: C

Correct: For a patient with no allergies to penicillin or amoxicillin, the standard prophylactic drug regimen is 2 g of amoxicillin 1 hour before the procedure.

Incorrect choices: These choices do not represent the American Heart Association regimen to prevent endocarditis subsequent to a dental procedure.

REF: Table 7-7: Prophylactic Antibiotic Drug Regimens for Dental Procedures | p. 90

OBJ: 7

1. If a patient requires premedication with antibiotics before a dental procedure and he or she is allergic to penicillins or ampicillin but can take oral medication, the drug of choice is:

a.	tetracycline.
b.	metronidazole.
c.	cephalexin.
d.	amoxicillin.

ANS: C

Correct: The drug of choice is 2 g of cephalexin. Alternatively, 600 mg of clindamycin, or 500 mg of azithromycin, or 500 mg of clarithromycin may be prescribed.

Incorrect choices: Tetracycline and metronidazole are not recommended antibiotics for immunoprophylaxis prior to a dental procedure in order to prevent endocarditis. Amoxicillin is contraindicated because it is a relative of ampicillin.

REF: Table 7-7: Prophylactic Antibiotic Drug Regimens for Dental Procedures | p. 90

OBJ: 7

1. Both the American Dental Association (ADA) and the American Academy of Orthopedic Surgeons (AAOS) continue to recommend that all patients receive antibiotic prophylaxis before certain dental procedures during the first _____ after total joint replacement.

a.	6 months
b.	1 year
c.	2 years
d.	7 years

ANS: C

Correct: The ADA and AAOS recommend that all patients receive antibiotic prophylaxis before certain dental procedures during the first 2 years after total joint replacement. Whether the use of antibiotics is indicated after the patient is 2 years postreplacement surgery should be determined by those involved most closely with the patient’s condition.

Incorrect choices: The remaining choices do not correctly represent the recommended time for antibiotic prophylaxis following total joint replacement.

REF: Antibiotic Prophylaxis Used in Dentistry (Prosthetic Joint Prophylaxis) | p. 91

OBJ: 7

MULTIPLE RESPONSE

1. Which of the following statements are true concerning antibiotic-resistant infections? (Select all that apply.)

a.	More than 10% of patients with antibiotic-resistant infections in the United States each year will die from their infection.
b.	Natural resistance occurs when an organism that was previously sensitive to an antimicrobial agent develops resistance.
c.	Microbial organisms have the ability to transfer genetic material from one to another so that an organism may become resistant to an antibiotic without ever having been exposed to the antibiotic.
d.	The development of new antibiotics has greatly reduced the number of antibiotic-resistant bacteria over the past 10 years.

ANS: A, C

Correct: There are a reported 2 million cases of antibiotic-resistant infections in the United States each year with approximately 230,000 reported deaths from these infections. One organism may transfer DNA to another via transduction, transformation, or bacterial conjugation. The first organism, which is resistant to one or more antibiotics, transfers its genetic material to a second organism. The second organism, which was not previously resistant, thus becomes resistant to the same antibiotic as the first organism without ever having been exposed to that antibiotic.

Incorrect choices: Natural resistance occurs when an organism has always been resistant to an antimicrobial agent because of the bacteria’s normal properties such as lipid structures in the cell wall. The number of antibiotic-resistant bacteria has increased dramatically over the past 10 years, and many bacterial infections are becoming resistant to some of the most commonly prescribed antibiotics.

REF: Resistance | p. 72 OBJ: 1

1. Which of the following groups of penicillins are most commonly used in dentistry? (Select all that apply.)

a.	Penicillin G and V
b.	Penicillinase-resistant penicillins
c.	Amoxicillin
d.	Extended-spectrum penicillins

ANS: A, C

Correct: The penicillins can be divided into four major groups. The first group contains penicillin G and V, the second group is composed of the penicillinase-resistant penicillins, the third group contains amoxicillin, and the fourth group consists of extended-spectrum penicillins. The first and third groups are commonly used in dentistry.

Incorrect choices: Penicillinase-resistant penicillins should be reserved for use against only penicillinase-producing staphylococci. Extended-spectrum penicillins have a wider spectrum of action than penicillin G and are used to treat systemic infections.

REF: Penicillins | p. 75 OBJ: 4

1. Which of the following are true of a stage 3 infection? (Select all that apply.)

a.	Most patients will require the use of antibiotics.
b.	The infection contains both gram-positive and gram-negative organisms.
c.	Clindamycin and metronidazole are useful antibiotics.
d.	The organisms have coalesced into one area.

ANS: C, D

Correct: The organisms have coalesced into one area in a stage 3 infection. The use of an antibiotic with anaerobic coverage is warranted if a chronic stage 3 infection persists or if the patient is immunocompromised. Clindamycin and metronidazole are the two antibiotics with the most anaerobic coverage.

Incorrect choices: Incision and drainage are most often sufficient for patients with a stage 3 infection. The organisms are almost solely anaerobic.

REF: Clindamycin | p. 82 | Metronidazole | pp. 82-83 | Rational Use of Antiinfective Agents in Dentistry (Stage 3) | p. 84 OBJ: 6

1. Which of the following are true about sulfamethoxazole (SMX) and trimethoprim (TMP)? (Select all that apply.)

a.	They are bactericidal.
b.	They act by sequential inhibition of folic acid synthesis.
c.	They are used to treat urinary tract infections (UTIs).
d.	They are often used to treat refractory periodontitis.

ANS: B, C

Correct: Sulfamethoxazole and trimethoprim are folate synthesis inhibitors. They are commonly used in combination as co-trimoxazole, SMX-TMP, Bactrim, or Septra. This drug is indicated for the treatment of selected urinary tract infections and selected respiratory and gastrointestinal infections. It is used to treat acute otitis media in children.

Incorrect choices: SMX-TMP is bacteriostatic against a wide variety of gram-positive bacteria and some gram-negative bacteria. SMX-TMP has no documented use in dentistry. Pediatric patients coming to the dental office may be taking it to prevent chronic ear infections.

REF: Antimicrobial Agents for Nondental Use (Sulfamethoxazole-Trimethoprim) | p. 86

OBJ: 5