MOSBY PHARMA

Question 1

Answer 1

ANS: 1I; 2F; 3J; 4D; 5G; 6H; 7E; 8A; 9B; 10C

Question 2

Answer 2

ANS: 1E; 2G; 3F; 4H; 5I; 6 J; 7B; 8A; 9C; 10D

Question 3

3. Aspirin is approved to treat each of the following
   conditions EXCEPT one. Which one is the
   EXCEPTION?
   A. Pain
   B. Fever
   C. Asthma
   D. Arthritis
   E. Dysmenorrhea

Answer 3

ANS: C
Aspirin should not be used in persons with asthma (C)
because this population is more likely to have a
hypersensitivity reaction, with the incidence ranging
from 5% to 15%. Pain (A), fever (B), arthritis (D),
and dysmenorrhea (E) are all approved indications for
aspirin use.

Question 4

5. Antiinflammatory, antipyretic, and analgesic effects are
   associated with which drug?
   A. Codeine
   B. Ibuprofen
   C. Hydrocodone
   D. Acetaminophen

Answer 4

ANS: B
Nonsteroidal antiinflammatory drugs (NSAIDs) such
as ibuprofen (B) block the enzyme cyclooxygenase,
which results in its antiinflammatory, antipyretic,
and analgesic effects. Codeine (A) and hydrocodone
(C) are opioids and have only analgesic effects.
Acetaminophen (D) has antipyretic and analgesic
effects but no antiinflammatory effect.

Question 4

4. Which beverage should not be given concurrently with
   tetracycline?
   A. Apple juice
   B. Tomato juice
   C. 2% milk
   D. Carbonated soda

Answer 4

ANS: C
Milk (C) contains calcium, a divalent cation, which
reduces the intestinal absorption of tetracycline by
forming nonabsorbable chelates of tetracycline. Apple
juice (A), tomato juice (B), and carbonated soda (D) do
not interfere with tetracycline absorption.

Question 5

6. Patients taking metronidazole hydrochloride (HCl)
   (Flagyl) should be advised to avoid which substance?
   A. Milk
   B. Antacids
   C. Grapefruit juice
   D. Mouth rinses with alcohol

Answer 5

ANS: D
Ingestion of metronidazole HCl (Flagyl) (D) with
alcohol may result in a disulfiram (Antabuse)–like reaction. Symptoms include nausea, abdominal
cramps, flushing, vomiting, or headache. Milk (A),
antacids (B), and grapefruit juice (C) will not cause
this interaction with metronidazole.

Question 5

7. Each of the following is a characteristic of an ideal local
   anesthetic EXCEPT one. Which one is the EXCEPTION?
   A. Reversible
   B. Slow onset
   C. Lack of systemic toxicity
   D. Absence of local reactions

Answer 5

ANS: B
In dentistry, a local anesthetic with a relatively rapid
onset of action, not a slow onset (B), is required so
that the time between the administration of the local
anesthetic and the beginning of a painful dental
procedure can be minimized. Reversibility (A) of the
actions of the local anesthetic is necessary so that
the patient can regain normal sensation in the tissue.
Lack of systemic toxicity (C) is necessary for patient
safety. Local reactions (D) such as tissue irritation are
considered unwanted and undesirable.

Question 6

8. Epinephrine is combined with a local anesthetic to
   A. enhance systemic local anesthetic absorption.
   B. prolong the duration of action of the local
   anesthetic.
   C. delay the onset of action of the local anesthetic.
   D. increase the potency of the local anesthetic.

Answer 6

ANS: B
Epinephrine (B) binds to alpha-receptors in the blood
vessels and causes vasoconstriction, thus prolonging the
action of the local anesthetic, decreasing the amount of
blood flow to the local tissue, and reducing the potential
for systemic toxicity. Because of reduced blood flow
to the area, there is actually a decrease in the systemic
absorption (A) of the local anesthetic. Epinephrine
accelerates the onset of action (C) of the local anesthetic
because it decreases its systemic absorption. Epinephrine
has no effect on the potency (D) of the local anesthetic

Question 7

11. Albuterol (Proventil, Ventolin) is a short-acting beta
    2-agonist that can be administered via a metereddose inhaler. Albuterol (Proventil, Ventolin) is
    recommended as an emergency treatment for dental
    patients who experience in-office asthma attacks.
    A. Both statements are true.
    B. Both statements are false.
    C. The first statement is true, and the second statement
    is false.
    D. The first statement is false, and the second
    statement is true.

Answer 7

ANS: A
Both statements are true (A) because Albuterol
(Proventil, Ventolin) is a beta 2-agonist drug that is
used treat asthma. It is administered via a metered-dose
inhaler for the treatment of intermittent asthma or an
acute attack. Albuterol (Proventil, Ventolin) is used by
dental offices as an emergency drug for dental patients
who suffer an acute asthma attack. Choices B, C, and
D do not accurately reflect the statements.

Question 8

9. Extrapyramidal adverse effects caused by
   phenothiazine antipsychotic drugs
   A. can be treated with anticholinergic drugs.
   B. affect muscle control (dystonic reactions).
   C. include akathisia.
   D. A, B, and C
   E. A and B only

Answer 8

ANS: D
D is the correct choice, as options A, B, and C are all
correct. Anticholinergic drugs (A) such as benztropine
(Cogentin) and trihexyphenidyl (Artane) can treat these
side effects. Dystonic reactions (B) and akathisia (C)
are types of extrapyramidal effects. Answer (E) does
not include all of the correct possibilities.

Question 9

10. Second-generation antihistamines such as loratadine
    (Claritin) are less sedating than their predecessors in
    therapeutic doses because they
    A. bind only to histamine 2 (H2
    )-receptors.
    B. do not penetrate the blood–brain barrier.
    C. are combined with decongestants for their central
    nervous system (CNS) stimulant activity.

Answer 9

ANS: B
Second-generation antihistamines (B) cannot cross the
blood–brain barrier to be distributed to the brain and
therefore cause little to no sedation. Although these drugs
have some binding to H2
-receptors (A), this is not the
reason for their lack of sedating effects. Second-generation
antihistamines (C) are not CNS stimulants, but they may be combined with decongestants to treat nasal congestion,
not because of their stimulating effects.

Question 10

13. When using an EpiPen, the dosage for an adult will be
    metered in which milligram increments?
    A. 300mg
    B. 30mg
    C. 0.3mg
    D. 0.15mg
    E. 15mg

Answer 10

ANS: C
The usual adult dosage of epinephrine is 0.3mg (C).
The dose for children is usually 0.15mg (D). Choices
A, B, and E are far too high dosages to be safe.

Question 10

12. Patients who have been prescribed ipratropium bromide
    (Atrovent), an anticholinergic drug for the treatment of
    chronic obstructive pulmonary disease (COPD) should
    be instructed to do what after each inhaler use?
    A. Rinse with water, swish, and swallow after each
    inhalation
    B. Rinse with water, swish, and expectorate after each
    inhalation
    C. Rinse with water, swish, expectorate, and brush
    after each inhalation
    D. Rinse with water, swish, expectorate, and brush
    after the morning inhalation only

Answer 10

ANS: B
Ipratropium bromide (Atrovent) is an anticholinergic
drug administered via a metered-dose inhaler and
is the drug of choice for COPD. The side effects of
ipratropium bromide include significant dry mouth
(xerostomia), teeth staining, and taste alterations.
Patients should be instructed to rinse the mouth with
water, swish, and expectorate after each inhalation
(B) to minimize these adverse effects and prevent
excessive systemic absorption. Patients should not
swallow after rinsing and swishing (A) because it can
cause a sore dry throat and exacerbate dry mouth.
Brushing is not necessary in addition to rinsing,
swishing, and expectorating (C and D).

Question 11

14. Each of the following is a possible side effect of an
    anticholinergic drug EXCEPT one. Which one is the
    EXCEPTION?
    A. Salivation
    B. Constipation
    C. Mydriasis
    D. Tachycardia

Answer 11

ANS: A
Anticholinergic drugs prevent secretions such as
saliva (A). Anticholinergics antagonize the cholinergic
system, and this may result in side effects such as
constipation (B), mydriasis (C), and tachycardia (D).

Question 12

15. Which drug is used to prevent an attack of gout?
    A. Colchicine
    B. Aspirin
    C. Probenecid
    D. Codeine

Answer 12

ANS: C
Probenecid (C) is used to prevent an attack of gout,
as it blocks the tubular reabsorption of filtered urate,
prevents new tophi, and mobilizes those present.
Colchicine (A) is used to treat an acute attack of gout.
Aspirin (B) is contraindicated for patients with gout
because it may counteract the uricosuric effects of
probenecid. Codeine (D) is not a gout medication.

Question 13

16. Which drug should NOT be given to a patient with a
    true allergy to codeine?
    A. Oxycodone (Percodan, Percocet, Tylox)
    B. Buprenorphine (Buprenex)
    C. Pentazocine (Talwin-NX)
    D. Propoxyphene (Darvon)

Answer 13

ANS: A
Oxycodone (Percodan, Percocet, Tylox) (A) should
not be given to a patient with a true codeine allergy
because it is a member of the morphine/codeine group
of opioid analgesics, which are likely to exhibit crossallergenicity. Buprenorphine (Buprenex) (B) is not
related to any of the other opioid groups and is unlikely
to cause cross-allergenicity. Pentazocine (Talwin-NX)
(C) is a member of the morphine group. Propoxyphene
(Darvon) (D) is a member of the methadone group, so
cross-allergenicity is unlikely.

Question 14

17. Which drug is commonly used as an antitussive?
    A. Dextromethorphan
    B. Pentazocine (Talwin-NX)
    C. Propoxyphene (Darvon, Darvocet N-100)
    D. Diphenoxylate

Answer 14

ANS: A
Dextromethorphan (A), an opioid-like compound,
is commonly used as an antitussive; it is the “DM”
found in cough syrups. Pentazocine (Talwin-NX)
(B) is a narcotic used to treat mild to moderate pain.
Propoxyphene (C) is found in Darvocet N-100 and is
used to treat mild to moderate pain. Diphenoxylate
(D), combined with atropine, is found in Lomotil and
is used in the treatment of diarrhea.

Question 15

18. Which antibiotic is contraindicated in pregnant
    patients?
    A. Tetracycline
    B. Erythromycin
    C. Penicillin
    D. Amoxicillin

Answer 15

ANS: A
Tetracycline (A) should not be used in pregnant women
because of the effect it can have on the developing
teeth and skeleton of the fetus. Erythromycin (B),
penicillin (C), and amoxicillin (D) are not associated
with teratogenicity and therefore are commonly used in
pregnant women.

Question 16

19. Each of the following agents has good absorption
    through the gastrointestinal (GI) tract EXCEPT one.
    Which one is the EXCEPTION?
    A. Itraconazole (Sporanox)
    B. Griseofulvin (Fulvicin P/G, Grisactin Ultra)
    C. Terbinafine (Lamisil)
    D. Nystatin (Mycostatin, Nilstat)

Answer 16

ANS: D
Nystatin (Mycostatin, Nilstat) (D), when taken orally,
is not absorbed but is excreted unchanged in feces Itraconazole (Sporanox) (A), griseofulvin (Fulvicin
P/G, Grisactin Ultra) (B), and terbinafine (Fulvicin
P/G, Grisactin Ultra) (C) all have good oral absorption.

Question 17

20. All of the following drugs would be contraindicated in
    patients with peptic ulcers EXCEPT one. Which one is
    the EXCEPTION?
    A. Aspirin
    B. Acetaminophen
    C. Ibuprofen
    D. Pilocarpine

Answer 17

ANS: B
Acetaminophen (B) does not cause gastrointestinal (GI)
upset or bleeding and so is considered safe for patients
with gastric ulcers. Aspirin (A) and ibuprofen (C) both
cause significant GI upset and gastric bleeding in a
significant patient population and are contraindicated
in patients with peptic ulcers. Pilocarpine (D), a
parasympathetic agonist, increases secretions, including
gastric acid, exacerbating peptic ulcer symptoms; it is,
therefore, contraindicated in these patients.

Question 18

24. Which drug is associated with xerostomia?
    A. Cyclobenzaprine
    B. Tetracycline
    C. Clindamycin (Cleocin)
    D. Cyclosporine (Sandimmune)

Answer 18

ANS: A
Cyclobenzaprine (Flexeril) (A) is a muscle relaxant,
which is associated with xerostomia. Tetracycline
(B) is associated with discoloration of developing
teeth. Clindamycin (Cleocin) (C) is associated
with pseudomembranous colitis. Cyclosporine
(Sandimmune) (D) is known to cause gingival
enlargement.

Question 19

21. Which general anesthetic may cause respiratory
    acidosis with deeper levels of anesthesia?
    A. Enflurane
    B. Isoflurane
    C. Sevoflurane
    D. Halothane

Answer 19

ANS: B
Isoflurane (B) causes irritation and significant
respiratory acidosis. Enflurane (A), sevoflurane (C),
and halothane (D) are not associated with either
excessive irritation or respiratory acidosis.

Question 20

22. Which is the shortest-acting barbiturate?
    A. Pentobarbital (Nembutal)
    B. Phenobarbital (Luminal)
    C. Mephobarbital (Mebaral)
    D. Methohexital (Brevital)

Answer 20

ANS: D
Methohexital (Brevital) (D) is an ultra-short-acting
barbiturate. Pentobarbital (Nembutal) (A) is a shortacting barbiturate. Phenobarbital (Luminal) (B)
and mephobarbital (Mebaral) (C) are long-acting
barbiturates.

Question 21

23. Beriberi is caused by a severe deficiency of
    A. ascorbic acid.
    B. niacin.
    C. thiamine.
    D. folic acid.

Answer 21

ANS: C
Beriberi is the result of a severe deficiency of thiamine
(C). Scurvy is caused by a deficiency of ascorbic acid
(A). Pellagra is produced by a deficiency of niacin (B).
Megaloblastic anemia is produced by a deficiency in
folic acid (D)

Question 22

25. All of the following are characteristics of xylitol
    EXCEPT one. Which one is the EXCEPTION?
    A. It inhibits the attachment of biofilm to teeth.
    B. It prevents the transmission of oral bacteria from
    mother to child.
    C. It reduces the levels of Streptococcus mutans in
    saliva and plaque.
    D. It is bactericidal to Streptococcus mutans in saliva
    and plaque.

Answer 22

ANS: D
The mechanism of xylitol’s anticaries action is
bacteriostatic (D), not bactericidal (D). The main
strains of S. mutans and S. sanguis cannot metabolize
xylitol, and this effect is potentiated with the addition of
sorbitol. Xylitol has been found to inhibit the attachment
of biofilm to teeth (A), prevent the transmission of oral
bacteria from mother to child (B), and reduce the levels
of S. mutans in saliva and plaque (C).

Question 23

26. Which drug is a common calcium channel blocker?
    A. Verapamil (Calan, Isoptin).
    B. Furosemide (Lasix).
    C. Warfarin (Coumadin).
    D. Lovastatin (Mevacor).

Answer 23

ANS: A
Verapamil (Calan, Isoptin) (A) is a common
calcium channel blocker. Furosemide (Lasix) (B)
is a loop diuretic. Warfarin (Coumadin) (C) is an
oral anticoagulant. Lovastatin (Mevacor) (D) is a
hydroxymethylglutaryl coenzyme A reductase inhibitor

Question 24

27. In addition to treatment of tonic-clonic and partial
    seizure disorders, carbamazepine (Tegretol) is also
    used in the treatment of
    A. trigeminal neuralgia.
    B. parkinson disease.
    C. chronic pain syndromes.
    D. A, B, and D.
    E. A and C only.

Answer 24

ANS: E
Carbamazepine (Tegretol) is used in the treatment
of trigeminal neuralgia (A) and other chronic pain
syndromes (C) in addition to some seizure disorders
(E). Parkinson disease (B) is treated with dopamine
agonists and anticholinergics, but carbamazepine is not
used in its treatment. Choice D does not contain the
correct components.

Question 25

28. Lithium (Eskalith, Lithobid) is commonly used in the
    treatment of
    A. schizophrenia.
    B. migraine headaches.
    C. bipolar depression.
    D. anxiety disorder.
    E. obsessive–compulsive disorder.

Answer 25

ANS: C
Bipolar depression (C) is commonly treated with lithium
(Eskalith, Lithobid). Antipsychotics are the drugs of
choice for the treatment of schizophrenia (A). Migraine
headaches (B) are treated with propranol, and a variety
of other medicines. Anxiety disorder (D) and obsessive–
compulsive disorder (E) are treated with antidepressants.

Question 26

30. Glucocorticoids should NOT be used to treat
    A. pemphigus vulgaris.
    B. herpetic gingivostomatitis.
    C. erythema multiforme.
    D. desquamative gingivitis.

Answer 26

ANS: B
Glucocorticoids may exacerbate infections such
as herpetic gingivostomatitis (B), which is a viral
infection, and therefore are contraindicated for
infectious oral lesions. Pemphigus vulgaris (A),
erythema multiforme (C), and desquamative gingivitis
(D) are all noninfectious oral lesions, which are
effectively treated with systemically administered
steroids.

Question 26

29. Which agent is an autocoid known for stimulating
    secretion from salivary glands?
    A. Histamine
    B. Pilocarpine
    C. Substance P
    D. Bradykinin

Answer 26

ANS: C
Substance P (B) is an autocoid that stimulates secretion
from salivary glands. Histamine (A) and bradykinin
(D) do not have the ability to stimulate salivary gland
secretion. Pilocarpine (B) does stimulate secretion
from salivary glands, but it is a parasympathetic
agonist, not an autocoid.

Question 27

34. Which of the following drugs is the BEST choice for
    treating an opioid overdose?
    A. Flumazenil (Romazicon)
    B. Prochlorperazine (Compazine)
    C. Diphenhydramine (Benadryl)
    D. Naloxone (Narcan)

Answer 27

ANS: D
Naloxone (Narcan) (D), an opioid receptor antagonist,
reverses the actions of other opioids. Flumazenil
(Romazicon) (A), a benzodiazepine receptor antagonist, may not have any impact on the opioid
overdose. Prochlorperazine (Compazine) (B) is one
of a class of antipsychotic medications prescribed for
treatment of nausea and vomiting and may exacerbate
the symptoms of opioid overdose. Intravenous
diphenhydramine (Benadryl) (C) is an antihistamine
that may reverse some of the actions of the overdose,
but it is not the best drug choice.

Question 27

31. Which oral antidiabetic agent needs to be administered
    for 6 to 14 weeks to reach its maximal therapeutic
    effect?
    A. Rosiglitazone (Avandia)
    B. Tolbutamide (Orinase)
    C. Exenatide (Byetta)
    D. Glimepiride (Amaryl)

Answer 27

ANS: A
Rosiglitazone (Avandia) (A) may take up to 6 to
14 weeks to achieve its maximum effect. Tolbutamide
(Orinase) (B) and glimepiride (Amaryl) (D) work
much faster than rosiglitazone. Exenatide (Byetta)
(C) is not an oral antidiabetic agent; it is administered
through subcutaneous injection.

Question 28

32. Which drug is used to manage the nausea and vomiting
    caused by antineoplastic therapy?
    A. Omeprazole (Prilosec)
    B. Prochlorperazine (Compazine)
    C. Cisplatin (Platinol)
    D. Codeine

Answer 28

ANS: B
Prochlorperazine (Compazine) (B) is a phenothiazine
(antiemetic drug), which is used to control nausea and
vomiting. Omeprazole (Prilosec) (A) is a proton pump
inhibitor used in the treatment of excessive stomach
acid, not as an antiemetic. Cisplatin (Platinol) (C) is an
antineoplastic agent. Codeine (D) is a narcotic analgesic,
and nausea and vomiting are some of its side effects.

Question 29

33. Which agent is used to treat ONLY allergen-induced
    asthma?
    A. Omalizumab (Xolair)
    B. Cromolyn (Intal, Nasalcrom)
    C. Fluticasone (Flovent)
    D. Zileuton (Zyflo)

Answer 29

ANS: A
Omalizumab (Xolair) (A) is the first of a new class
of medications used to treat allergen-induced asthma.
Cromolyn (Intal, Nasalcrom) (B) is effective only for
the prophylaxis of asthma. Fluticasone (Flovent) (C)
is an inhaled corticosteroid used to control symptoms
in patients with mild, moderate, or severe persistent
asthma, but not specifically allergen-induced asthma.
Zileuton (Zyflo) (D) is a 5-lipoxygenase inhibitor,
which prevents the synthesis of leukotrienes.

Question 30

35. Which of the following is the BEST choice of local
    anesthetic when performing a dental procedure on a
    pregnant patient?
    A. Mepivacaine (Carbocaine)
    B. Lidocaine (Xylocaine)
    C. Bupivacaine (Marcaine)
    D. Articaine (Septocaine)

Answer 30

ANS: B
Lidocaine (Xylocaine) (C) is a category B drug (no
evidence of risk in humans) and is the best drug choice
for the pregnant patient. Mepivacaine (Carbocaine)
(A), bupivacaine (Marcaine) (C), and articaine
(Septocaine) (D) are all pregnancy category C drugs;
that is, there is a risk of fetal harm if the drug is
administered.

Question 31

36. Lidocaine (Xylocaine) achieves anesthesia primarily
    by acting at which sites?
    A. Dopamine receptors
    B. Chloride channels
    C. Sodium channels
    D. Serotonin receptors

Answer 31

ANS: C
Lidocaine (Xylocaine) binds to and blocks sodium
channels (C), which results in inhibition of nerve
membrane depolarization and prevention of nerve
conduction to the central nervous system (CNS),
causing reversible anesthesia. Local anesthetics such as
lidocaine are often termed “sodium channel blockers.”
Dopamine (A) and serotonin receptors (D) are targets
of several drugs that work on the CNS. Chloride
channels (B) are targets of many sedatives.

Question 32

37. The drug metronidazole (Flagyl) is most useful in
    therapy for which oral condition?
    A. Candidiasis
    B. Aggressive periodontitis
    C. Aphthous stomatitis
    D. Xerostomia
    E. Herpes labialis

Answer 32

ANS: B
Metronidazole (Flagyl) is used clinically for two
reasons: (1) treatment of certain parasitic diseases
and (2) treatment of infections caused by anaerobic
bacteria. Periodontal disease (B) typically involves
anaerobic bacteria. Metronidazole is not effective
against fungi such as Candida albicans and may
increase the risk of oral candidiasis (A). Aphthous
stomatitis (C) usually does not require medication.
Xerostomia (dry mouth) (D) is not helped by
metronidazole; the drug does not stimulate salivary
flow. Metronidazole is not effective against Herpes
simplex virus, the causative agent of cold sores (herpes
labialis) (E).

Question 33

38. Two cartridges of lidocaine (Xylocaine; 2% with
    1:100,000 epinephrine) are to be administered to a
    dental patient. The patient is also receiving treatment
    for hypertension. What is the maximum safe dosage of
    epinephrine?
    A. No safe dosage of epinephrine for patients with
    cardiovascular disease exists.
    B. 0.4mg epinephrine
    C. 0.04mg epinephrine
    D. 0.2mg epinephrine

Answer 33

ANS: C
A dosage of 0.04mg (C) epinephrine, found in
two cartridges of lidocaine (Xylocaine) (2%) with
1:100,000 epinephrine, is the safest dose for patients
with cardiovascular disease and is even termed “the
cardiac dose.” In the past, vasoconstrictors were
avoided in patients with cardiovascular disease (A)
because of the drug’s sympathetic nervous system
effects in raising heart rate and blood pressure.
Research has shown, however, that patients may
produce far higher amounts of endogenous epinephrine
if anesthesia is insufficient, so it is safer to control
the dose. Doses of 0.4mg (B) and 0.2mg (D) of a
vasopressor are high enough to have an adverse effect
on the cardiovascular system in a patient with disease.

Question 34

39. In a patient suffering from chronic dry mouth
    (xerostomia) caused by Sjögren disease with some
    salivary gland function remaining, which drug would
    be MOST effective in stimulating salivary flow?
    A. Amitriptyline (Elavil)
    B. Cevimeline (Evoxac)
    C. Oxymetazoline (Afrin)
    D. Salmeterol (Serevent)

Answer 34

ANS: B
Cevimeline (Evoxac) (B) stimulates muscarinic
cholinergic receptors, directly stimulating saliva
secretion from the salivary gland cells. Amitriptyline
(Elavil) (A), an antidepressant drug that blocks
muscarinic receptors, would decrease salivary
flow. Oxymetazoline (Afrin) (C) stimulates alpha
2-adrenergic receptors and has much less effect on
salivary flow compared with cevimeline. Salmeterol
(Serevent) (D) stimulates beta 2-adrenergic receptors
and has little effect on salivary flow rate.

Question 35

40. The patient reports taking lisinopril (Prinivil) on
    the medication history. Each of the following is an
    indication for lisinopril (Prinivil) EXCEPT one. Which
    one is the EXCEPTION?
    A. Chronic heart failure
    B. Hypertension
    C. Hypercholesterolemia
    D. Arrhythmia
    E. Recent history of myocardial infarction

Answer 35

ANS: C
Lisinopril (Prinivil) is an angiotensin-converting
enzyme (ACE) inhibitor, with multiple indications
in treatment of cardiovascular conditions. ACE
inhibitors do not have a significant effect on
hypercholesterolemia (C). Lisinopril reduces the load
on the heart by vasodilation, which makes it useful
in treating heart failure (A) by reducing the risk of
deleterious vascular and cardiac remodeling. By
inhibiting the production of angiotensin II, lisinopril
reduces blood pressure in hypertensive patients (B).
It is also indicated for patients with arrhythmias (D)
and recent myocardial infarctions (E) to reduce the
likelihood of subsequent cardiac events

Question 36

41. The U.S. Food and Drug Administration (FDA)
    has indicated that the maximum daily dose of
    acetaminophen (Tylenol) should be 3000mg. Which
    is the major toxicity concern for acetaminophen that
    prompted this reduced dose?
    A. Kidney disease
    B. Liver toxicity
    C. Excessive sedation
    D. Asthmatic attacks
    E. Bladder infections

Answer 36

ANS: B
In high doses, acetaminophen may be converted
to toxic radicals, which damage the liver (B).
Patients with preexisting liver disease, those
with alcoholism, and others are more susceptible.
Acetaminophen poisoning accounts for a large
number of emergency visits to the hospital, as well
as many deaths as a result of liver damage. Although
kidney damage (A) has been associated with the
use of nonnarcotic analgesics, these disorders have
usually occurred after long-term chronic use and
when combinations of these types of drugs have
been used. Acetaminophen does not have noticeable
sedative (C) properties. It does not worsen asthma
(D) unless an allergic reaction to acetaminophen
occurs, which is rare. There is no known link
between acetaminophen and bladder infections (E),
since the drug has no major effect on structures in
the urinary tract

Question 37

42. Which analgesic drug reduces blood clotting for the
    longest period?
    A. Ibuprofen (Motrin)
    B. Naproxen (Aleve, Naprosyn)
    C. Acetaminophen (Tylenol)
    D. Codeine
    E. Aspirin

Answer 37

ANS: E
Only aspirin (E) irreversibly inhibits cyclooxygenase,
which inhibits the synthesis of thromboxane A2
,
and inhibits platelet aggregation for the life of the
platelet (7–10 days). Nonsteroidal antiinflammatory
drugs (NSAIDs) such as ibuprofen (A) and
naproxen (B) may also affect blood clotting but
do so only for a short time because they reversibly
inhibit cyclooxygenase and inhibit the synthesis of
thromboxane A2
. Acetaminophen (C) has a minor
effect on blood clotting in most cases. Codeine (D)
has no major effect on blood clotting mechanisms,
including platelet aggregation.

Question 38

45. Which drug has the MOST potent antiinflammatory
    effect?
    A. Alendronate (Fosamax)
    B. Prednisone (Deltasone)
    C. Atenolol (Tenormin)
    D. Raloxifene (Evista)
    E. Fluoxetine (Prozac)

Answer 38

ANS: B
Prednisone (Deltasone) (B), a glucocorticoid, has several
mechanisms that make it a potent antiinflammatory drug
used in a variety of settings. Inhibition of phospholipase
A2
, a key enzyme in the inflammatory prostanoid and
leukotriene pathway is a primary antiinflammatory
action. Alendronate (Fosamax) (A) is a bisphosphonate
that is used to reduce bone turnover. Atenolol
(Tenormin) (C) is a beta-adrenergic receptor blocker
that has a number of cardiovascular effects but not an
antiinflammatory effect. Raloxifene (Evista) (D) is an
estrogen receptor agonist–antagonist, more commonly
known as a selective estrogen receptor modulator
(SERM), with a beneficial effect in the treatment of
postmenopausal osteoporosis, but no antiinflammatory
action. Fluoxetine (Prozac) (E) is a selective serotonin
reuptake inhibitor (SSRI), whose action in the brain
mediates its antidepressant effect.

Question 39

44. Drugs that inhibit hydroxymethylglutaryl coenzyme
    A (HMG CoA) reductase are often used to treat which
    type of disorder?
    A. Arrhythmias (e.g., atrial fibrillation)
    B. Hypertension
    C. Blood lipid disorders (e.g., hypercholesterolemia)
    D. Systemic fungal infections (e.g., candidiasis)
    E. Osteoarthritis

Answer 39

ANS: C
HMG CoA reductase is an important enzyme in
the synthesis of cholesterol in the liver (C). Drugs
such as Lovastatin (Mevacor) and other “statins”
reduce plasma cholesterol by this mechanism. Statins
have a less direct effect on cardiac arrhythmias (A)
and hypertension (B), although lowering plasma
cholesterol often has a beneficial effect in patients
receiving these agents. Statins have little if any effect
on fungal organisms (D). Statins do not treat the
inflammation or the pain of osteoarthritis (E).

Question 39

46. The patient has recently been prescribed a drug by a
    neurologist to treat a painful jaw. The pain was sharp
    and intermittent and seemed to be triggered by the
    slightest touch.
    The patient could not remember the
    name of the disorder, but it was explained to the patient
    that the prescribed “pain killer” was an antiepileptic
    drug used for this type of pain.
    Which would be the
    most likely drug prescribed?

A. Oxycodone (in Percodan, Percocet)
B. Dihydrocodeine (in Synalgos DC)
C. Celecoxib (Celebrex)
D. Carbamazepine (Tegretol)
E. Acetaminophen (Tylenol)

Answer 39

ANS: D
The pain described is consistent with trigeminal
neuralgia (tic douloureux) because of the type of
pain, the location of the pain involving cranial nerve
V, and the fact that a neurologist made the diagnosis.
Carbamazepine (Tegretol) (D) is a drug commonly
used to treat trigeminal neuralgia. It is effective in
inhibiting nerve conduction by blocking neuronal
sodium channels, and this also makes it useful to treat certain types of seizure disorders. Oxycodone
(Percodan, Percocet) (A) and dihydrocodeine
(Synalgos DC) (B) are both opioids and are useful
in treating pain but are less effective in treating the
neuropathic type pain described here. Celecoxib
(Celebrex) (C) is a cyclooxygenase-2 (COX-2)
inhibitor and is used as an antiinflammatory and
analgesic agent. Acetaminophen (Tylenol) (E) is not
particularly effective in treating neuropathic pain

Question 40

43. Which drug’s antimicrobial action is based on its
    ability to inhibit cross-linking of the peptidoglycan
    chains in bacterial cell walls?
    A. Amoxicillin (Amoxil)
    B. Clindamycin (Cleocin)
    C. Clarithromycin (Biaxin)
    D. Ciprofloxacin (Cipro)
    E. Gentamicin (Garamycin)

Answer 40

ANS: A
Amoxicillin (Amoxil) (A), like other penicillins,
inhibits the enzyme transpeptidase, which catalyzes
cross-linking in bacterial cell walls. Clindamycin
(Cleocin) (B), clarithromycin (Biaxin) (C), and
gentamicin (Garamycin) (E) all inhibit ribosomal
protein synthesis in bacteria. Ciprofloxacin (Cipro)
(D) inhibits deoxyribonucleic acid (DNA) function by
inhibiting DNA enzymes.

Question 41

47. A patient being treated for xerostomia with pilocarpine
    (Salagen) is most likely to experience which side
    effect?
    A. Sweating
    B. Tachycardia
    C. Urinary retention
    D. Hypertension
    E. Constipation

Answer 41

ANS: A
Sweating (A) is the most common complaint of
patients taking muscarinic cholinergic receptor
agonists such as pilocarpine (Salagen) for the
treatment of xerostomia. Although innervated by
the sympathetic nervous system, sweat glands have
muscarinic receptors that respond to postganglionic
cholinergic nerves, resulting in increased secretion
and these receptors also respond to pilocarpine.
Cholinergic postganglionic nerves are otherwise
rare in the sympathetic nervous system. Although
tachycardia (B) is a possibility because of vasodilation,
the vasodilation is usually mild or nonexistent with the
oral doses used in this situation. Muscarinic receptor
stimulation would tend to have very mild effects
opposite to urinary retention (C) and constipation
(E). Hypertension (D) is not likely to occur with the
effect of pilocarpine, since cholinergic agonists usually
decrease blood pressure and slow heart rate.

Question 42

52. Which major neurotransmitter in autonomic
    ganglia leads to a rapid excitatory postsynaptic
    potential?
    A. Dopamine
    B. Epinephrine
    C. Norepinephrine
    D. Acetylcholine
    E. Serotonin

Answer 42

ANS: D
Acetylcholine (D) is the major neurotransmitter in
ganglia and carries the stimulatory message from
the preganglionic neuron to the postganglionic
neuron. Acting on nicotinic cholinergic receptors
linked to sodium channels, acetylcholine causes a
rapid excitatory postsynaptic potential. Dopamine
(A), norepinephrine (C), or both are released
from interneurons in sympathetic ganglia, but
they cause an inhibitory postsynaptic potential.
Epinephrine (B) plays no major role in preganglionic
transmission. Serotonin (E) may have a minor role
in neurotransmission in some ganglia, but only in a
delayed response in the postganglionic neurons.

Question 42

48. Which drug most effectively blocks the itching, pain,
    and swelling from histamine released in the skin?
    A. Chlorthalidone (Hygroton)
    B. Doxazosin (Cardura)
    C. Candesartan (Atacand)
    D. Diphenhydramine (Benadryl)
    E. Isoproterenol (Isuprel)

Answer 42

ANS: D
Diphenhydramine (Benadryl) (D) is an antihistamine
that blocks histamine H1
receptors and inhibits the
above effects of histamine on nerves and blood
vessels. Chlorthalidone (Hygroton) (A) is a thiazidetype diuretic. Doxazosin (Cardura) (B) is an alpha
1-adrenergic receptor blocker. Candesartan (Atacand)
(C) is an angiotensin II receptor blocker. Isoproterenol
(Isuprel) (E) is a nonselective beta-adrenergic receptor
agonist. These drugs are typically used in the treatment
of hypertension but have no or minimal effects on
acute responses to histamine because they do not block
histamine receptors or alleviate acute inflammation

Question 43

49. Each of these drugs is used to treat asthma EXCEPT
    one. Which one is the EXCEPTION?
    A. Fluticasone (Flonase)
    B. Metoprolol (Lopressor)
    C. Salmeterol (Serevent)
    D. Ipratropium (Atrovent)
    E. Montelukast (Singulair)

Answer 43

ANS: B
Metoprolol (Lopressor) (B) is a selective beta
1-adrenergic receptor blocker. Beta-blockers are contraindicated in asthma because by blocking
the beta 2-adrenergic receptors in the lung,
bronchoconstriction may occur. Selective beta
1-adrenergic receptor blockers have primarily
cardiac effects and are less likely to cause
bronchoconstriction than nonselective beta-adrenergic
receptor blockers. These drugs should still be
used with caution in patients with asthma, since
these drugs have no direct benefit in the relief of
asthma symptoms. Fluticasone (Flonase) (A) is a
glucocorticoid, with an antiinflammatory effect in
the lung, reducing the inflammatory component of
asthma. Salmeterol (Serevent) (C) is a long-acting
beta 2-adrenergic receptor agonist, which causes
bronchodilation. Ipratropium (Atrovent) (D) is an
antimuscarinic, anticholinergic drug that blocks the
bronchoconstricting effect of acetylcholine that is
released in the lung. Montelukast (Singulair) (E) is
a cysteinyl leukotriene 1 receptor blocker. Cysteinyl
leukotrienes are inflammatory mediators that
contribute to bronchoconstriction.

Question 44

51. A patient who has asthma and has been taking oral
    theophylline (Theolair) for several months develops
    an acute infection in the oral cavity. Since the patient
    reports an allergy to penicillin, oral erythromycin
    ethylsuccinate (E.E.S.), at a dose of 400mg four
    times a day, is prescribed. Two days later, the patient
    begins to feel ill, reporting dizziness, nervousness,
    confusion, nausea and vomiting, and rapid heart rate.
    Which is the most likely explanation for the patient’s
    symptoms?
    A. Erythromycin inhibited the renal excretion of
    theophylline.
    B. Erythromycin enhanced the gastric absorption of
    theophylline.
    C. Theophylline increased the affinity of erythromycin
    at the site of action.
    D. Theophylline decreased the excretion of
    erythromycin.
    E. Erythromycin inhibited the hepatic metabolism of
    theophylline.

Answer 44

ANS: E
Erythromycin inhibits the liver enzymes (the
cytochromes) needed to metabolize many drugs,
including theophylline (E). The symptoms described
are consistent with theophylline toxicity, which occurred when failure to metabolize theophylline
caused the plasma levels to rise to harmful levels.
Erythromycin does not affect renal excretion of
other drugs (A). Erythromycin may cause severe
gastrointestinal distress but does not enhance
absorption of other drugs (B). Theophylline does not
affect cell affinity for erythromycin (C), or decrease
its excretion (D). Because of the low therapeutic index
of theophylline, another choice of antibiotic would be
better.

Question 45

50. The antipsychotic effect of thioridazine (Mellaril)
    is largely caused by which mechanism in the
    brain?
    A. Blocking the reuptake of norepinephrine and
    serotonin
    B. Blocking sodium channels in nerves
    C. Blocking calcium channels in nerves
    D. Enhancing the effect of gamma aminobutyric acid
    (GABA) on chloride channels
    E. Blocking dopamine receptors on nerves

Answer 45

ANS: E
Potencies of traditional antipsychotic drugs such as
thioridazine are correlated with their affinities for
D2
dopamine receptors (E). Blocking the reuptake of
norepinephrine and serotonin (A) is the mechanism
of action of several antidepressants. Blocking
sodium channels in the central nervous system
(CNS) (B) is a mechanism of action of several
antiepileptic drugs such as phenytoin. Blocking
calcium channels in the CNS (C) is a characteristic
of several antiepileptic drugs used in the treatment
of absence (petit mal) seizures. Most sedatives act
by enhancing the effect of GABA (D), an inhibitory
neurotransmitter, on chloride channels

Question 46

54. Which of the following BEST describes the
    mechanism of action of phentolamine?
    A. Reversal of calcium channel blockage
    B. Blockage of calcium channels
    C. Reversal of sodium channel blockage
    D. Blockage of sodium channels

Answer 46

ANS: C
Phentolamine is a drug that causes reversal of
sodium channel blockage (C), shortening the time of
soft tissue anesthesia following a dental procedure.
The mechanism is related to its ability to block the vasoconstriction resulting from alpha-adrenergic
receptor stimulation caused by epinephrine and
norepinephrine. The resulting vasodilation leads to
more rapid removal of the local anesthetic from the
area of injection after the phentolamine is injected.
Reversal of calcium channel blockage (A) is not an
action of phentolamine (OraVerse). Calcium channel
blockage (B) is the action of hypertensive medications
such as verapamil (Calan, Isoptin). Blockage of sodium
channels (D) is the action of the local anesthetic agent,
not phentolamine.

Question 47

53. Sumatriptan (Imitrex, Alsuma) is a drug that is
    commonly used to treat which disorder?
    A. Hypercholesterolemia
    B. Migraine headaches
    C. Asthma attacks
    D. Atrial fibrillation
    E. Opioid toxicity

Answer 47

ANS: B
Sumatriptan (Imitrex, Alsuma) is an agonist at
serotonin 5HT1B/1D receptors. Sumatriptan and other
triptans cause constriction of intracranial blood vessels,
reduce pain fiber activity, and reduce inflammation
associated with migraine headaches (B). The triptans
have little effect at other receptors and the mechanism
of action of sumatriptan has little benefit in the
treatment of other disorders. Sumatriptan does little
to change cholesterol metabolism (A) or to reduce
bronchoconstriction in asthma attacks (C). Sumatriptan
has no obvious benefit on ion channel activity in the
heart (D) and may even be associated with certain
arrhythmias. Sumatriptan has no activity on opioid
receptors (E).

Question 48

55. Which drug has the broadest antibacterial
    spectrum?
    A. Amoxicillin (Amoxil)
    B. Clavulanic acid (in Augmentin)
    C. Dicloxacillin (Dynapen)
    D. Penicillin G (Pfizerpen)
    E. Penicillin V (Penicillin VK)

Answer 48

ANS: A
Amoxicillin (Amoxil) (A) is the penicillin with a
broadest spectrum of action and is called an “extendedspectrum” penicillin because it has greater activity
compared with the other penicillins listed against
gram-negative bacilli. Clavulanic acid (in Augmentin)
(B) is not a penicillin, although its structure resembles
penicillin with a beta-lactam ring, it has little
antibacterial effect by itself. It is a beta-lactamase
inhibitor and is added to amoxicillin to prevent
amoxicillin’s destruction by bacterial penicillinases.
Dicloxacillin (Dynapen) (C) is a narrow-spectrum
penicillin but is resistant to some penicillinases.
Penicillin G (Pfizerpen) (D) and penicillin V
(Penicillin VK) (E) have both have essentially the
same narrow spectrum of action against many grampositive bacteria and some gram-negative cocci.
Although less active than penicillin G and penicillin V,
dicloxacillin’s resistance to penicillinase makes it useful
in the treatment of infections caused by penicillinaseproducing Staphylococcus aureus

Question 49

56. Which drug reduces coagulation by inhibiting the
    activation (carboxylation) of certain clotting factors in
    the liver?
    A. Aspirin
    B. Alteplase (t-PA) (Activase)
    C. Clopidogrel (Plavix)
    D. Heparin
    E. Warfarin (Coumadin)

Answer 49

ANS: E
Warfarin (Coumadin) (E) competitively inhibits
vitamin K epoxide reductase, acting as a vitamin
K antagonist. This action leads to inhibition of
carboxylation of prothrombin factors VII, IX, and X,
as well as other factors leading to reduced coagulation
capacity. The other drugs listed act on elements in
blood. Aspirin (A) and clopidogrel (Plavix) (C) are
inhibitors of platelet aggregation; aspirin, due to its
effect on cyclooxygenase, inhibits the production of
thromboxane A2
, and clopidogrel inhibits the effect
of adenosine diphosphate on platelets. Alteplase
(t-PA, Activase) (B) binds to fibrin and leads to
the hydrolysis and breakup of fibrin. Heparin (D)
reduces blood clotting by accelerating the activity of
antithrombin III and by other mechanisms.

Question 50

57. Which is NOT a characteristic associated with nitrous
    oxide (NO) used for conscious sedation?
    A. Has analgesic effect
    B. Has ability for rapid induction of conscious
    sedation
    C. Causes skeletal muscle relaxation
    D. Is heavier than air
    E. Is odorless

Answer 50

ANS: C
NO is not an effective skeletal muscle relaxant (C)
even at higher anesthetic doses. NO has significant
analgesic effects (A). It is noted for rapid induction (B)
because of its low blood-to-gas solubility coefficient.
NO is heavier than air (D) and may accumulate at floor
level under conditions of poor ventilation or conditions
of poor scavenging. It is odorless (E) and tasteless to
the patient.

Question 51

58. Which drug is used as an antidepressant and is
    considered an SSRI?
    A. Amitriptyline (Elavil)
    B. Bupropion (Wellbutrin)
    C. Haloperidol (Haldol)
    D. Lithium carbonate (Eskalith)
    E. Paroxetine (Paxil)

Answer 51

ANS: E
Paroxetine (Paxil) (E) is an antidepressant that
primarily blocks the reuptake of serotonin in the brain.
Amitriptyline (Elavil) (A), also an antidepressant,
blocks both serotonin and norephinephrine reuptake
mechanisms nonselectively. The mechanism of
bupropion (Wellbutrin) (B) is not as well understood,
although reuptake of dopamine may play a role.
Haloperidol (Haldol) (C) is an antipsychotic drug that
blocks the dopamine receptors. Lithium (Eskalith)
(D) is used in treatment of the manic phase of bipolar
disease or manic-depressive illness.

Question 52

59. Which drug would be indicated in the treatment
    of methicillin-resistant Staphylococcus aureus
    (MRSA)?
    A. Cephalexin (Keflex)
    B. Clarithromycin (Biaxin)
    C. Dicloxacillin (Dynapen)
    D. Penicillin V (Pen-Vee-k)
    E. Vancomycin (Vancocin)

Answer 52

ANS: E
Vancomycin (Vancocin) (E) is the antibiotic indicated
for the treatment of S. Aureus. It is active in the
presence of penicillinases produced by S. aureus
and other mechanisms of resistance to beta-lactams.
MRSA is largely resistant to clarithromycin (Biaxin)
(B). Dicloxacillin (Dynapen) (C) is very similar to
methicillin and is ineffective against this infection.
Resistance by MRSA also extends to other betalactam antibiotics such as cephalexin (Keflex) (A) and
penicillin V (Pen-Vee-k) (D)

Question 52

60. Curare-type drugs such as vecuronium (Norcuron)
    cause muscle relaxation by which mechanism?
    A. Activating chloride channels in the CNS
    B. Blocking nicotinic receptors at the skeletal
    neuromuscular junction
    C. Reducing blood flow to the skeletal muscles
    D. Reducing calcium release from intracellular storage
    sites in skeletal muscles
    E. Blocking ganglionic transmission

Answer 52

ANS: B
Curare-type drugs are competitive blockers of the
nicotinic type of cholinergic receptors in the skeletal
neuromuscular junction (B). Activation of chloride
channels (A), either through GABA or independently of
GABA, is the mechanism that applies to many sedative
hypnotics that have some ability to relax skeletal
muscle. Reducing blood flow (C) is not relevant to the
action of any muscle relaxer. Reducing calcium release from intracellular stores (D) is the mechanism of action
of dantrolene (Dantrium), which is not a curare-type
drug. Blocking ganglionic transmission (E) would
be ineffective in causing skeletal muscle relaxation
because skeletal muscles are innervated by somatic
nerves, which do not have ganglia

Question 53

61. A drug that has an effect on the fetal development is
    said to have a/an
    A. side effect.
    B. toxic effect.
    C. therapeutic effect.
    D. teratogenic effect.
    E. idiosyncratic reaction.

Answer 53

ANS: D
A drug that causes an adverse reaction in the
developing fetus is termed teratogenic effect (D). The
FDA has ranked drugs into five pregnancy categories:
A, B, C, D, and X, ranked from least risky to most
risky. A side effect (A) is a dose-related reaction that
is not part of the desired therapeutic effect. A toxic
effect (B) is an extension of the pharmacologic effect
resulting from the drug’s excessive and harmful effect
on the target organ. The therapeutic effect (C) is the
desired drug effect on target organs. An idiosyncratic
effect or reaction (E) is a genetically related abnormal
drug response that is atypical compared with that in the
general population.

Question 54

62. Which drug or drug class is most likely to result in
    bone loss when administered chronically in typical
    clinical doses?
    A. Alendronate (Fosamax)
    B. Ethinyl estradiol (Estinyl)
    C. Conjugated estrogens (Premarin)
    D. Raloxifene (Evista)
    E. Prednisone (Deltasone)

Answer 54

ANS: E
Prednisone (Deltasone) (E), as well as other
glucocorticosteroids, promotes a negative calcium
balance by decreasing calcium absorption from the
gastrointestinal (GI) tract. They also increase osteoclast
activity and decrease osteoblast activity in bone and
have other mechanisms as well. These effects may, and
often do, lead to osteoporosis. Alendronate (Fosamax)
(A) is a bisphosphonate, and bisphosphonates bind to
bone remodeling surfaces, reducing the number and
activity of osteoclasts. This is useful in treating certain
bone loss disorders such as osteoporosis and Paget
disease. Estrogens, including ethinyl estradiol (Estinyl)
(B) and conjugated estrogens (Premarin) (C), increase
osteoblast activity, which then suppresses the action
of osteoclasts. Raloxifene (Evista) (D) is a selective
estrogen receptor modulator (SERM), which has a
similar beneficial effect on bone. It is more selective
than ethinyl estradiol or conjugated estrogens in its
ability to stimulate estrogen receptors.

Question 55

63. Which anesthetic has the longest duration of action?
    A. Articaine (Septocaine)
    B. Bupivacaine (Marcaine)
    C. Lidocaine (Xylocaine)
    D. Mepivacaine (Carbocaine)
    E. Prilocaine (Citanest)

Answer 55

ANS: B
Bupivacaine (Marcaine) (B) is chemically similar
to mepivacaine but with an additional substitution
that is highly lipid soluble. This change increases the potency and duration of the action of bupivacaine for
up to 8 hours of analgesia, making it the longest-acting
local anesthetic that is commonly used in dentistry.
Articaine (Septocaine) (A) has a duration of action of
3 to 4 hours, making it an intermediate-acting local
anesthetic. Lidocaine (Xylocaine) without epinephrine
(C) and mepivacaine (Carbocaine) (D) have a short
duration of 30 to 90 minutes of analgesia. Prilocaine
(Citanest) (E) without epinephrine has an intermediate
duration of 2 to 4 hours of analgesia

Question 56

64. Which drug inhibits renin release from the kidneys?
    A. Candesartan (Atacand)
    B. Digoxin (Lanoxin)
    C. Enalapril (Vasotec)
    D. Metoprolol (Lopressor)
    E. Nifedipine (Procardia)

Answer 56

ANS: D
Metoprolol (Lopressor) (D), blocks beta 1-adrenergic
receptors in the juxtaglomerular cells of the kidney’s
afferent arterioles, inhibiting the release of renin.
Renin catalyzes the conversion of angiotensinogen
to angiotensin I, which causes vasoconstriction, and
stimulates aldosterone release. Aldosterone promotes
sodium retention in the kidney, further raising blood
pressure by vasoconstriction. Blocking the renin–
angiotensin pathway reduces blood pressure and
the demand on the heart, making this class of drugs
important in the treatment of hypertension and heart
failure. Candesartan (Atacand) (A) and enalapril
(Vasotec) (C) also inhibit this pathway but do so
“downstream” from renin release: Enalapril inhibits
angiotensin-receptor-enzyme (ACE); and candesartan
blocks the angiotensin II receptor. Digoxin (Lanoxin)
(B) stimulates the heart directly, increasing its force
of contraction. It does so by inhibiting the sodium–
potassium pump (Na+,K+–adenosine triphosphatase [ATPase]) in the plasma membranes of cardiac cells.
Nifedipine (Procardia) (E) is a calcium channel
blocker, which reduces the contraction of cardiac
muscle and increases vasodilation of the arteries—two
methods of reducing blood pressure. This action is not
linked to renin release

Question 57

65. While obtaining a patient’s medical history, the dental
    hygienist learns that the patient takes cimetidine (Tagamet)
    prescribed for peptic ulcer. Which is the MOST likely
    scenario if local anesthesia (LA) is administered?
    A. LA is ineffective in therapeutic doses.
    B. LA may cause systemic toxicity in therapeutic doses.
    C. There is no change in the efficacy of LA.
    D. LA causes an allergic reaction.

Answer 57

ANS: B
Cimitidine (Tagamet) is a prototype of the
H2
-receptor antagonists which inhibit secretion of
gastric acid by competitive inhibition of the
H2
-receptors of the parietal cells of the stomach. One
of the most serious adverse effects of cimitidine is its
ability to inhibit liver microsomal enzymes via the
cytochrome P-450 enzymes, slowing the elimination
of some drugs in blood plasma. This may lead to
increased drug levels and toxicity (B), even when
drugs such as lidocaine are given in therapeutic doses.
The clinician should exercise caution and use the
lowest possible dose of local anesthetic in patients on
cimetidine. Concurrent administration of cimitidine
(Tagamet) would not negate lidocaine’s local
anesthetic properties (A). The efficacy of lidocaine
would be increased with administration of cimitidine
(Tagamet) (C). Allergic reactions to lidocaine are
rare, and cimitidine (Tagamet) does not increase these
types of reactions (D)