Ivms-USMLE Step 1 Review Course- Summative Assessment-pharmacology
- 1.
A 17-year-old male was placed on carbamazepine therapy by his neurologist to control newly developed seizures of unknown etiology. The patient was also recently given a macrolide antibiotic by his family physician for a presumed “walking pneumonia.” Halfway through his antibiotic course, the patient again developed seizures. What could account for this new seizure activity?
- A.
Inhibition of the cytochrome P-450 monooxygenase system
- B.
Induction of the cytochrome P-450 monooxygenase system
- C.
Impairment of renal excretion of the antiseizure medication
- D.
Induction of glucuronyl transferase activity in the liver
- E.
Reduction in the amount of nicotinamide adenine dinucleotide phosphate (NADPH)
Correct Answer
B. Induction of the cytochrome P-450 monooxygenase systemExplanation
1. The answer is B. Both carbamazepine and macrolide antibiotics are known inducers of the cytochrome P-450 system. Thus it is likely that the original therapeutic levels of antiseizure medicine was decreased to nontherapeutic levels when the metabolism of the drug was increased with the addition of the antibiotic. Some common drugs that inhibit P-450 include cimetidine, chloramphenicol, and disulfiram. Impaired renal excretion results in increased, not decreased, levels of drugs. The induction of glucuronyl transferase is a possible drug interaction, although less likely in this case. The P-450 system requires NADPH, and therefore a deficiency would result in decreased, not increased, activity by the system.Rate this question:
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- 2.
A 21-year-old male sustains multiple blunt traumas after being beaten with a baseball bat by a gang. Aside from his fractures, a serum creatine kinase measurement is dramatically elevated and the trauma team is worried as the myoglobinuria caused by the trauma can cause kidney failure. They immediately begin to administer bicarbonate to alkalinize the urine. How does this serve to decrease myoglobin levels?
- A.
Increasing glomerular filtration
- B.
Promoting renal tubular secretion
- C.
Inhibiting renal tubular reabsorption
- D.
Increasing hepatic first-pass metabolism
- E.
Inducing the P-450 system
Correct Answer
C. Inhibiting renal tubular reabsorptionExplanation
The answer is C. Alterations in urinary pH alters renal reabsorption of substances. In this case, alkalinization traps filtered myoglobin in the urine so that it cannot be reabsorbed, which leads to decreased levels in the serum. The other mechanisms such as increasing glomerular filtration, promoting tubular secretion are other potential ways to alter plasma drug/metabolite levels. Myoglobin is not hepatically metabolized; therefore, hepatic or P-450 metabolism would not alter myoglobin levels.Rate this question:
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- 3.
Which of the following correctly describes the formula for a loading dose?
- A.
Loading dose = (Desired plasma concentration of drug) × (clearance)
- B.
Loading dose = (Clearance) × (Plasma drug concentration)
- C.
Loading dose = (0.693) × (Volume of distribution)/(Clearance)
- D.
Loading dose = (Amount of drug administered)/(Initial plasma concentration)
- E.
Loading dose = (Desired plasma concentration of the drug) × (Volume of distribution)
Correct Answer
E. Loading dose = (Desired plasma concentration of the drug) × (Volume of distribution)Explanation
The answer is E. Loading dose = (Desired plasma concentration of the drug) × (Volume of distribution). The formula for the maintenance dose, once the loading dose is given, = (Desired plasma concentration of drug) × (Clearance). The elimination rate = (Clearance) × (Plasma drug concentration). The half-life of a drug = (Amount of drug administered)/(Initial plasma concentration). And lastly, the volume of distribution = (Amount of drug administered)/(Initial plasma concentration).Rate this question:
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- 4.
A 32-year-old HIV-positive male follows up with an infectious disease (ID) specialist in the clinic. The results of his recent blood work suggest that the virus has become resistant to multiple nucleoside reverse transcriptase inhibitors. The ID specialist decides to include in the treatment a nonnucleoside inhibitor (nevirapine), which works by binding to a site near the active site on the reverse transcriptase. Nevirapine is an example of what?
- A.
Full agonist
- B.
Reversible competitive antagonist
- C.
Partial agonist
- D.
Noncompetitive antagonist
- E.
Irreversible competitive antagonist
Correct Answer
D. Noncompetitive antagonistExplanation
The answer is D. By definition, drugs that do not bind to the active site, such as nonnucleotide reverse transcriptase inhibitors, are noncompetitive antagonists. They function by causing changes in the active site so that it cannot bind its native substrate. Agonists are drugs that elicit the same activity as the endogenous substrate, whereas partial agonists only induce some of the activities of the endogenous substrate. Competitive inhibitors, like nucleoside reverse transcriptase inhibitors, can be either reversible or irreversible.Rate this question:
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- 5.
Which of the following drugs is a selective α-adrenergic receptor agonist that is available over-the-counter?
- A.
Epinephrine
- B.
Phenylephrine
- C.
Isoproterenol
- D.
Norepinephrine
- E.
Phentolamine
Correct Answer
B. pHenylepHrineExplanation
The answer is B. Phenylephrine is a selective α1-adrenergic agonist that decreases nasal secretions by causing nasal vasoconstriction, decreasing the formation of such secretions. Epinephrine is the most potent of the adrenergic receptor agonists, followed by norepinephrine. Isoproterenol is the weakest antagonist. But the previous three agents also bind β-adrenergic receptors and are not available over the counter. Phentolamine is just the opposite, an α1-adrenergic antagonist.Rate this question:
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- 6.
Pilocarpine is what type of pharmacologic agent?
- A.
Indirect muscarinic agonist
- B.
α2-Adrenergic agonist
- C.
Carbonic anhydrase inhibitor
- D.
β-Adrenergic antagonist
- E.
Direct-acting muscarinic agonist
Correct Answer
E. Direct-acting muscarinic agonistExplanation
The answer is E. Pilocarpine is a direct-acting muscarinic agonist used in the management of acute narrow-angle glaucoma, often along with an indirect-acting muscarinic agonist like physostigmine. Carbonic anhydrase inhibiters (e.g., acetazolamide), β-adrenergic agonists, and even α2-adrenergic agonists can be used in the treatment of glaucoma.Rate this question:
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- 7.
Which of the following is a short-acting acetylcholinesterase inhibitor?
- A.
Pyridostigmine
- B.
Bethanechol
- C.
Edrophonium
- D.
Scopolamine
- E.
Methantheline
Correct Answer
C. EdropHoniumExplanation
The answer is C. In myasthenia gravis, autoantibodies develop to nicotinic acetylcholine receptors, causing impaired neuromuscular dysfunction that results in muscular fatigue. This fatigue can be treated with acetylcholinesterase inhibitors. Edrophonium is the shortest-acting agent in this class and used to diagnosis this disorder, with such weakness immediately corrected with its use. Pyridostigmine is a longer-acting agent used in the treatment of the disease. Bethanecol is a direct-acting muscarinic cholinergic agonist, whereas both scopolamine and methantheline are both muscarinic-receptor antagonists.Rate this question:
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- 8.
Dantrolene
- A.
Inhibits calcium release from the sarcoplasmic reticulum
- B.
Functions as a GABAB receptor agonist
- C.
Facilitates GABA activity in the CNS
- D.
Reactivates acetylcholinesterase
- E.
Competitively inhibits the effects of acetylcholine
Correct Answer
A. Inhibits calcium release from the sarcoplasmic reticulumExplanation
The answer is A. Dantrolene is used in the treatment of malignant hyperthermia and works by inhibiting the release of calcium from the sarcoplasmic reticulum. Baclofen, an antispasmatic used in the treatment of multiple sclerosis, inhibits synaptic transmission as a GABAB-receptor agonist. Benzodiazepines function to facilitate GABA activity in the CNS and spinal cord. Pradoxime reactivates acetylcholinesterase. Nondepolarizing neuromuscular junction blockers such as atracurium competitively inhibit the effects of acetylcholine.Rate this question:
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- 9.
A 63-year-old male, with a history of multiple myocardial infarctions is admitted for shortness of breath. A diagnosis of congestive heart failure is made on clinical grounds, and a cardiologist orders a positive inotropic agent for his heart failure. He is also concerned about maintaining perfusion to the kidneys, so an agent that increases renal blood flow is also desirable. Which of the following agents produces both of these desired effects?
- A.
Epinephrine
- B.
Dopamine
- C.
Isoproterenol
- D.
Terbutaline
Correct Answer
B. DopamineExplanation
The answer is B. Dopamine is useful in the management of congestive heart failure, as it has both positive inotropic effects on the heart and preserves blood flow to the kidneys. Epinephrine and isoproterenol increase cardiac contractility while decreasing peripheral resistance. Albuterol is a β1 agonist used in the management of asthma, and terbutaline is another β agonist used to suppress labor, in the event of threatened labor of a premature fetus.Rate this question:
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- 10.
Clonidine works by
- A.
Activating β1-adrenergic receptors
- B.
Activating α1-adrenergic receptors
- C.
Activating β2-adrenergic receptors
- D.
Activating α2-adrenergic receptors
- E.
Blocking β-adrenergic receptors
Correct Answer
D. Activating α2-adrenergic receptorsExplanation
The answer is D. Clonidine activates prejunctional α2-adrenergic receptors in the CNS to reduce sympathetic tone, thereby decreasing blood pressure. Activation of α1-adrenergic receptors increases blood pressure, and such agonists are used in the treatment of hypotension. β 1-adrenergic agonists are used primarily for increasing heart rate and contractility. β2-adrenergic agonists are used to dilate airways in the management of asthma. β-blockers are used in the treatment of angina and hypertension.Rate this question:
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- 11.
A 23-year-old female presents with hypertension, anxiety, and palpitations. Her thyroid-stimulating hormone levels are normal, but she has increased levels of urinary catecholamines. She is referred to a endocrine surgeon after a CT scan shows a unilateral pheochromocytoma. The surgeon should start therapy with which of the following agents prior to removing the lesion?
- A.
Dopamine
- B.
Phentolamine
- C.
. Pancuronium
- D.
Pseudoephedrine
- E.
Isoproterenol
Correct Answer
B. pHentolamineExplanation
The answer is B. An α-adrenergic blocker such as phentolamine is indicated for the treatment of pheochromocytomas in the preoperative state as well as if the tumor is inoperable. β-blockers are then used systemically, following effective α blockade, to prevent the cardiac effects of excessive catecholamines. Pseudoephedrine is an α -adrenergic antagonist available over the counter to relieve nasal discharge. There is no role for adrenergic receptor agonists such as dopamine or isoproterenol or for that matter nondepolarizing muscle relaxants such as pancuronium.Rate this question:
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- 12.
A 45-year-old male with a history remarkable for both asthma and angina now has a kidney stone stuck in his right ureter. The urologist needs to perform cystoscopy, but the anesthesiologist is concerned about using a β-blocker during surgery to control the patient's blood pressure in light of his history of asthma. Ultimately, it is decide to use an ultra-short-acting β-blocker and closely monitor both his blood pressure and respiratory status. Which of the following is best to use in this situation?
- A.
Atenolol
- B.
Norepinephrine
- C.
Albuterol
- D.
Pseudoephedrine
- E.
Esmolol
Correct Answer
E. EsmololExplanation
The answer is E. Esmolol is an ultra-short-acting β1 antagonist that is relatively specific for
the heart; however, the short half-life of this drug should allow the anesthesiologist to fine tune the delivery and readily reverse the effects should there be problems with respiration. Atenolol is a much longer acting agent that would not provide such control. Norepinephrine would actually adversely affect the patient's angina, as it is stimulatory to the heart. Albuterol is a β agonist used in the treatment of asthma. Pseudoephedrine is an over-the-counter α agonist used in cold formula preparations.Rate this question:
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- 13.
A neurosurgeon decides to start a patient on a diuretic that works by altering the diffusion of water relative to sodium (an osmotic diuretic) that is helpful in reducing cerebral edema. Which agent did the physician likely prescribe?
- A.
Furosemide
- B.
Hydrochlorothiazide
- C.
Spironolactone
- D.
. Acetazolamide
- E.
Mannitol
Correct Answer
E. MannitolExplanation
The answer is E. Mannitol is an osmotic diuretic frequently used in management of cerebral edema caused by various insults. This agent works by altering the diffusion of water relative to sodium by “binding” the water, with a resultant reduction of sodium reabsorption. Furosemide and hydrochlorothiazide act by directly altering reabsorption of sodium in various parts of the nephron (choices A and B). Spironolactone (choice C) antagonizes mineralocorticoid receptor. Acetazolamide inhibits carbonic anhydrase (choice D).Rate this question:
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- 14.
. Which of the following would be useful in treating nocturnal enuresis?
- A.
. Mannitol
- B.
Indomethacin
- C.
Furosemide
- D.
Vasopressin
- E.
Probenecid
Correct Answer
D. VasopressinExplanation
The answer is D. Vasopressin use can be tried in cases of recalcitrant nocturnal enuresis. Mannitol is most commonly used in management of cerebral edema (choice A). Indomethacin can occasionally be used as an antidiuretic agent in diabetic patients (choice B). Furosemide is used in congestive heart failure (choice C). Probenecid is used in treatment of gout (choice E).Rate this question:
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- 15.
Vasopressin
- A.
Reduces ADH levels
- B.
Increases permeability of the collecting duct
- C.
Inserts aquaporins into the plasma membrane of collecting duct cells
- D.
Increases diffusion of sodium
- E.
Reduces production of prostaglandins
Correct Answer
C. Inserts aquaporins into the plasma membrane of collecting duct cellsExplanation
The answer is C. Vasopressin causes specific water channels termed aquaporins II to be inserted into the plasma membrane of the luminal surface of the medullary collecting ducts. This directly affects permeability of the collecting duct (choice B). Under the conditions of dehydration, as is the case with this patient, the ADH levels increase (choice A). Choice D represents the mechanism of action of osmotic diuretics. Production of prostaglandins is reduced with the use of agents such as indomethacin (choice E).Rate this question:
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- 16.
AcA 45-year-old male with a 60-pack/year history of smoking presents to his primary care provider with loss of appetite, nausea, vomiting, and muscle weakness. His chest CT reveals enlarged hilar lymph nodes and a suspicious mass in the left hilar region. A presumptive diagnosis of lung cancer is made. Laboratory results reveal low levels of sodium, which in this setting has likely contributed to the syndrome of inappropriate ADH secretion. Which medication might be helpful for this patient's symptoms?
- A.
Clofibrate
- B.
Demeclocycline
- C.
Allopurinol
- D.
Acetazolamide
- E.
Furosemide
Correct Answer
B. DemeclocyclineExplanation
The answer is B. Demeclocycline is an ADH antagonist and as such is useful in treatment of SIADH, which is commonly seen in patients with lung cancer. Clofibrate (choice A) increases the release of ADH centrally. Allopurinol, acetazolamide, and furosemide do not affect actions of ADH to an appreciable degree (choices C, D, and E).Rate this question:
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- 17.
Which of the following drugs inhibits xanthine oxidase?
- A.
Colchicine
- B.
Indomethacin
- C.
Probenecid
- D.
Clofibrate
- E.
Allopurinol
Correct Answer
E. AllopurinolExplanation
The answer is E. Allopurinol is a xanthine oxidase inhibitor and is most commonly used in treatment of gout. It is not used for acute attacks, but rather for prevention of recurrent episodes. Colchicine (choice A) may be used for an acute episode, as well as in long-term therapy; however, it has a high incidence of side effects. Indomethacin (choice B) is useful for symptomatic treatment of gout. Probenecid (choice C) is also useful for prophylaxis of gout; however, it is not a xanthine oxidase inhibitor. This agent inhibits secretion of organic acids. Clofibrate (choice D) is used in treatment of hypercholesterolemia.Rate this question:
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- 18.
Which of the following is a common adverse effect of quinidine?
- A.
Cinchonism
- B.
Lupuslike syndrome
- C.
Seizures
- D.
Constipation
- E.
Pulmonary fibrosis
Correct Answer
A. CinchonismExplanation
The answer is A. Cinchonism, or ringing in the ears and dizziness, is common after quinidine use. Lupuslike syndrome (B) can be observed after the use of procainamide. Seizures may occur with lidocaine use (C). Diarrhea can occur with the use of quinidine, not constipation (D). Pulmonary fibrosis is a long-term complication of amiodarone use (E).Rate this question:
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- 19.
What is the mechanism of action of β-blockers in heart disease?
- A.
Prolongation of AV conduction
- B.
Activation of the sympathetic system
- C.
Promotion of automaticity
- D.
Increase in heart rate
- E.
Arteriolar vasodilation
Correct Answer
A. Prolongation of AV conductionExplanation
The answer is A. Beta-blockers prolong AV conduction. The reduce sympathetic stimulation (B). These agents depress automaticity (C). Beta-blockers decrease heart rate (D), and can cause arteriolar vasoconstriction (E).Rate this question:
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- 20.
Which of the following would be useful in the management of arrhythmia due to Wolf-Parkinson-White syndrome?
- A.
Digoxin
- B.
Lidocaine
- C.
Amiodarone
- D.
Adenosine
- E.
Atropine
Correct Answer
D. AdenosineExplanation
The answer is D. Adenosine, a class V antiarrhythmic, is used for the treatment of paroxysmal supraventricular tachycardias, including those of Wolf-Parkinson-White syndrome. Digoxin (A) and amiodarone (C) can be used for management of atrial fibrillation. Lidocaine is used in treatment of many arrhythmias (B). Atropine is used for bradyarrhythmias.Rate this question:
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- 21.
Which of the following inhibit HMG-CoA reductase?
- A.
Nicotinic acid
- B.
Rosuvastatin
- C.
Ezetimibe
- D.
Cholestyramine
- E.
Gemfibrozil
Correct Answer
B. RosuvastatinExplanation
The answer is B. Rosuvastatin is an HMG—CoA reductase inhibitor. Nicotinic acid (A) inhibits the process of esterification of fatty acids, thereby reducing plasma triglyceride levels. Ezetimibe (C) reduces cholesterol absorption. Cholestyramine can bind bile acids and prevents their enterohepatic circulation (D). Gemfibrozil (E) reduces hepatic synthesis of cholesterol.Rate this question:
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- 22.
Which of the following would be a good option to help a patient fall asleep with minimal “hangover”?
- A.
Secobarbital
- B.
Zolpidem
- C.
Chlordiazepoxide
- D.
Flumazenil
- E.
Buspirone
Correct Answer
B. ZolpidemExplanation
The answer is B. Zolpidem has actions similar to those of benzodiazepines, although it is structurally unrelated. It is used as a hypnotic and anxiolytic with minimal abuse potential. Barbiturates such as secobarbital are rarely used because of their lethality on overdose. Chlordiazepoxide is a long-acting benzodiazepine, whereas most hypnotics are short-acting benzodiazepines. Flumazenil is a benzodiazepine antagonist that will not reverse the effects of zolpidem. Buspirone is not used as a hypnotic and has little sedative effect.Rate this question:
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- 23.
Which of the following is a good choice to treat newly diagnosed generalized anxiety disorder (GAD) in a patient who is a truck driver?
- A.
Alprazolam
- B.
Triazolam
- C.
Buspirone
- D.
Trazodone
- E.
Thiopental
Correct Answer
C. BuspironeExplanation
The answer is C. Buspirone is a partial agonist of the 5-HT1A receptor that has efficacy comparable to that of benzodiazepines for the treatment of anxiety, although they are significantly less sedating. Alprazolam is an intermediate-acting benzodiazepine used in the treatment of GAD but still has some sedation, which would be undesirable in this situation. Triazolam is a short-acting benzodiazepine, and trazodone is a heterocyclic antidepressant, both used to induce sleep. Thiopental is a barbiturate sometimes used to induce anesthesia.Rate this question:
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- 24.
A 57-year-old male with a strong family history of Parkinson's disease sees a neurologist for an evaluation. On examination, the neurologist notes a slight pill-rolling tremor and subtle gait abnormalities. He begins treatment with levodopa, along with the addition of carbidopa. How does carbidopa work in this setting?
- A.
. Restores dopamine levels in the substantia nigra
- B.
Inhibits monoamine oxidase (MAOI)
- C.
Inhibits catechol-O-methyltransferase (COMT)
- D.
Functions as a dopamine agonist
- E.
Inhibits the metabolism of levodopa outside the CNS
Correct Answer
E. Inhibits the metabolism of levodopa outside the CNSExplanation
The answer is E. Carbidopa, unlike levodopa, does not penetrate the CNS; it does inhibit levodopa's metabolism in the gut, leading to lower doses of levodopa and decreased side effects. Levodopa is a precursor to dopamine and can help restore levels of dopamine in the substantia nigra. Monoamine oxidase inhibitors should not be used with caution along with levodopa, as this can lead to a hypertensive crisis. Bromocriptine is a dopamine agonist used in the treatment of Parkinson's disease. COMT inhibitors are yet another class of agents used in the treatment of Parkinson's disease.Rate this question:
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- 25.
The patient in the previous question returns to see his neurologist 3 years later. At this time the patient's symptoms have progressed, and he now has marked bradykinesia and a profound shuffling gait. In an attempt to prevent further deterioration, the neurologist prescribes a catechol-O-methyltransferase (COMT) inhibitor on top of the patient's levodopa and carbidopa. Which agent below is likely to have been added?
- A.
Entacapone
- B.
Selegiline
- C.
Ropinirole
- D.
Amantadine
- E.
Benztropine
Correct Answer
A. EntacaponeExplanation
The answer is A. Levodopa is metabolized, in part by COMT; therefore, an inhibitor such as entacapone is an adjunct treatment for patients on levodopa. It does however increase the side effects including diarrhea, postural hypotension, nausea, and hallucinations. Selegiline is a MAOI used in the treatment of Parkinson's disease. Ropinirole is a nonergot dopamine agonist used in early Parkinson's disease that may decrease the need for levodopa in later stages of the disease. Amantadine has an effect on the rigidity of the disease as well as the bradykinesia, although it has no effect on the tremor. Benztropine is an antimuscarinic used as an adjunct drug in Parkinson's disease.Rate this question:
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- 26.
Which of the following is a noncompetitive NMDA receptor inhibitor that can be used to treat Alzheimer's disease?
- A.
Memantine
- B.
Donepezil
- C.
Tacrine
- D.
Tolcapone
- E.
Pergolide
Correct Answer
A. MemantineExplanation
The answer is A. Memantine is an NMDA-receptor inhibitor that is well tolerated and shown to slow the rate of cognitive decline in Alzheimer's patients. Donepezil and tacrine are acetylcholinesterase inhibitors, which have shown similar activities. Tolcapone is a COMT inhibitor rarely used in Parkinson's disease because of the possibility of hepatic necrosis. Pergolide is an ergot derivative used as a dopamine agonist in the management of Parkinson's disease.Rate this question:
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- 27.
A 43-year-old high-profile attorney sees a psychiatrist with expertise in addiction medicine. He explains that he has recently received his third drunk driving citation and fears losing his license to practice unless he stops drinking altogether. He says he “just can't stop” once he starts. He tells the physician that he doesn't have time to attend Alcoholic Anonymous and “wants a pill.” The physician explains that there is something that might work if the patient is truly serious. What agent is the physician considering?
- A.
Lorazepam
- B.
Flumazenil
- C.
Naloxone
- D.
Disulfiram
- E.
Carbamazepine
Correct Answer
D. DisulfiramExplanation
The answer is D. Disulfiram is an inhibitor of aldehyde dehydrogenase, which blocks the breakdown of acetaldehyde to acetate during the metabolism of alcohol. The buildup of acetaldehyde results in flushing, tachycardia, hypertension and nausea to invoke a conditioned response to avoid alcohol ingestion. Lorazepam is useful in the prevention of seizures as a result of alcohol withdrawal, whereas carbamazepine is used should they develop. Flumazenil is used for benzodiazepine overdose and naloxone for opioid overdose.Rate this question:
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- 28.
A nonstimulant agent that can be used to treat attention-deficit/hyperactivity disorder (ADHD) is
- A.
Methylphenidate
- B.
Caffeine
- C.
Dextroamphetamine
- D.
Atomoxetine
- E.
Modafinil
Correct Answer
D. AtomoxetineExplanation
The answer is D. Atomoxetine is a nonstimulant drug used in the management of ADHD that works by inhibiting norepinephrine reuptake. The stimulate agents used for the treatment of ADHD include methylphenidate and dextroamphetamine and work by inhibiting dopamine reuptake. Caffeine is a stimulant in many beverages, which may have some role in the management of some headaches. Modafinil is a newer agent used in the treatment of narcolepsy.Rate this question:
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- 29.
Which of the following can be used to treat a 22-year-old with a recent diagnosis of schizophrenia?
- A.
Baclofen
- B.
Haloperidol
- C.
. Chloral hydrate
- D.
Phenobarbital
- E.
Imipramine
Correct Answer
B. HaloperidolExplanation
The answer is B. Haloperidol is an antipsychotic used in acute psychotic attacks and for the treatment of schizophrenia. It functions predominately as a dopamine-receptor blocker, predominately at the D2 receptor. Baclofen is a GABAB receptor antagonist that is used in the treatment of spinal cord injuries. Choral hydrate is a hypnotic agent that works similarly to ethanol. Phenobarbital is a barbiturate used in the treatment of seizures and as an anesthetic. Imipramine is a tricyclic antidepressant and is not used in schizophrenia.Rate this question:
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- 30.
Soon after drug administration, the patient in the above question begins making odd faces with spastic movements of his neck. Which of the following should be administered to treat these dystonic reactions?
- A.
Fluphenazine
- B.
Bromocriptine
- C.
Dantrolene
- D.
Prolactin
- E.
Benztropine
Correct Answer
E. BenztropineExplanation
The answer is E. Acute dystonias are a complication of antipsychotics that work primarily through dopamine D2 receptors and therefore have a high incidence of extrapyramidal effects. Haloperidol and agents such as fluphenazine are the most likely offenders. Such reactions are best managed with an anticholinergic such as benztropine. Another complication of haloperidol is the neuroleptic malignant syndrome, which is treated with the dopamine agonist bromocriptine as well as dantrolene. Hyperprolactinemia with galactorrhea is common with agents that block dopamine's actions, as dopamine normally represses prolactin release.Rate this question:
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- 31.
A Which of the following is a potential side effect of clozapine?
- A.
Cholestatic jaundice
- B.
QT prolongation
- C.
Agranulocytosis
- D.
Photosensitivity
- E.
Galactorrhea
Correct Answer
C. AgranulocytosisExplanation
The answer is C. Agranulocytosis occurs more frequently with clozapine than with other agents, requiring routine blood tests. It is the only agent that improves the negative symptoms of schizophrenia. Cholestatic jaundice and photosensitivity are common with chlorpromazine. Galactorrhea is a side effect of older high-potency agents that block dopamine. QT prolongation is a complication of agents such as thioridazine and ziprasidone.Rate this question:
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- 32.
Risperidone works primarily through inhibition of receptors for
- A.
Dopamine
- B.
Serotonin
- C.
Histamine
- D.
Acetylcholine
- E.
Norepinephrine
Correct Answer
B. SerotoninExplanation
The answer is B. The unique affinities of various antipsychotics result in their unique activities and their unique side effects. Risperidone is an atypical antipsychotic that works by blocking the 5-HT2A serotonin receptor. The older high-potency antipsychotics inhibit dopamine receptors. Agents such as clozapine inhibit histamine receptors. Chloropyramine has affinity for cholinergic as well as adrenergic receptors.Rate this question:
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- 33.
A 7-year-old boy is brought to the neurologist by his mother. She says that the boy's teacher says there are times in class when he stares “out into space” and smacks his lips. In the office the boy has one such episode while having an EEG, which demonstrates a 3-per-second spike and wave tracing. Which drug is the best for this absence seizure?
- A.
Phenytoin
- B.
Carbamazepine
- C.
Prednisone
- D.
Lorazepam
- E.
Ethosuximide
Correct Answer
E. EthosuximideExplanation
The answer is E. Ethosuximide is the drug of choice for absence seizures in children. Valproic acid has more side effects and therefore is a second-line drug. Prednisone is used in infantile seizures. Phenytoin and carbamazepine can be used in partial seizures or in tonic-clonic seizures. Lorazepam is often used in the treatment of status epilepticus.Rate this question:
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- 34.
Which of the following is a complication of phenytoin use?
- A.
Hepatotoxicity
- B.
Gingival hyperplasia
- C.
Thrombocytopenia
- D.
Aplastic anemia
- E.
Stevens-Johnson syndrome
Correct Answer
B. Gingival hyperplasiaExplanation
The answer is B. Gingival hyperplasia is a unique side effect of phenytoin, which can be partially avoided by meticulous oral hygiene. Several anticonvulsants can cause hepatotoxicity, including valproic acid and felbamate. Aplastic anemia is a rare, but potential complication of carbamazepine, ethosuximide, and felbamate. Valproic acid is also associated with thrombocytopenia. Ethosuximide has been associated with a severe form of erythema multiforme, the Steven-Johnson syndrome.Rate this question:
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- 35.
Tiagabine works by
- A.
Inhibiting GABA uptake by inhibiting the GABA transporter
- B.
Increasing GABA by stimulating its release from neurons
- C.
Increasing GABA-stimulated chloride channel opening
- D.
Prolonging GABA-induced channel opening
- E.
Blocking T-type calcium channels
Correct Answer
B. Increasing GABA by stimulating its release from neuronsExplanation
The answer is A. Tiagabine is an anticonvulsant used in conjunction with drugs such as phenytoin. Its mechanism is related to its ability to inhibit GABA transport into the cell, thereby decreasing GABA uptake. Gabapentin works by stimulating the release of GABA from neurons. Benzodiazepines function to increase GABA-stimulated chloride channel opening, whereas barbiturates prolong GABA- induced chloride channel opening. Ethosuximide works by blocking T-type calcium channels.Rate this question:
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- 36.
Which of the following agents is approved for treatment of diabetic neuropathy?
- A.
Phenytoin
- B.
Carbamazepine
- C.
Acetazolamide
- D.
Valproic acid
- E.
Gabapentin
Correct Answer
E. GabapentinExplanation
The answer is E. Many antiseizure drugs find applications for other diseases. Gabapentin is approved for the treatment of diabetic nephropathy, an unfortunate consequence in this patient's presentation. Phenytoin is also used for the treatment of arrhythmias. Carbamazepine is used in the management of trigeminal neuralgia. Acetazolamide, sometimes used as an treatment for absence seizure control, is used in the treatment of glaucoma. Valproic acid can be used in the prophylaxis of migraine headaches.Rate this question:
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- 37.
A 5-year-old boy is brought to the emergency room by his parents after they found him with an empty bottle of aspirin. They are not sure how many tablets the boy consumed. On examination, the child is hyperpneic and lethargic. While the emergent treatment is started, a sample is drawn for an arterial blood determination. What pattern is most likely to be indicated by the arterial blood gas values?
- A.
Mixed metabolic alkalosis and respiratory alkalosis
- B.
Mixed respiratory alkalosis and metabolic acidosis
- C.
Mixed respiratory acidosis and metabolic acidosis
- D.
Mixed respiratory acidosis and metabolic alkalosis
- E.
Mixed metabolic acidosis and metabolic alkalosis
Correct Answer
B. Mixed respiratory alkalosis and metabolic acidosisExplanation
The answer is B. Salicylate toxicity initially increases the medullary response to carbon dioxide, with resulting hyperventilation and respiratory alkalosis. Increases in lactic acid and ketone body formation result in a metabolic acidosis. All other choices are incorrect in this particular setting. Treatment includes correction of acid—base disturbances, replacement of electrolytes and fluids, cooling, alkalinization of urine, and forced diuresis.Rate this question:
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- 38.
Which of the following is an antineoplastic agent that has been shown to help patients with rheumatoid arthritis?
- A.
Valdecoxib
- B.
Ketorolac
- C.
Methotrexate
- D.
Entocort
- E.
Auranofin
Correct Answer
C. MethotrexateExplanation
The answer is C. From the presented list, only methotrexate is known to be an antineoplastic agent. This medication has been used successfully in rheumatoid arthritis and other rheumatologic conditions. Valdecoxib (A) is a COX-2 inhibitor that has been recently removed from the market. Ketorolac (B) is a powerful analgesic used for multiple autoimmune conditions. Entocort (D) is a glucocorticoid that can be used in some arthritides. Auranofin (E) is a gold compound that is rarely used anymore.Rate this question:
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- 39.
Which of the following is true regarding infliximab?
- A.
It is a recombinant antibody to TNF-α
- B.
It is a humanized antibody to TNF-α
- C.
It is a fusion protein that binds to TNF-α receptor
- D.
It is a recombinant protein resembling IL-1
- E.
It is a recombinant protein composed of a portion of LFA-3
Correct Answer
A. It is a recombinant antibody to TNF-αExplanation
The answer is A. Infliximab is a recombinant antibody to TNF-α it has been successfully used in the treatment of Crohn's disease, rheumatoid arthritis, and some other autoimmune conditions. Choice B represents Humira, an agent also used for rheumatoid arthritis. Choice C is Etanercept, a subcutaneous agent approved for treatment of rheumatoid arthritis. Choice D represents anakinra, an IL-1 blocker also used for rheumatoid arthritis. Choice E is alefacept, an agent used for psoriasis.Rate this question:
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- 40.
Which of the following is useful in an acute gout attack?
- A.
Probenecid
- B.
Sulfinpyrazone
- C.
Allopurinol
- D.
Colchicine
- E.
Celecoxib
Correct Answer
D. ColchicineExplanation
The answer is D. Colchicine is often used to treat an acute gouty attack. Probenecid (A) and sulfinpyrazone (B) reduce urate levels by preventing reabsorption of uric acid. These agents are used for chronic gout. Allopurinol (C) is a xanthine oxidase inhibitor; it is also used for treatment of chronic gout. Celecoxib is a COX-2 inhibitor that has been removed from the market.Rate this question:
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- 41.
What is the mechanism of action of tacrolimus?
- A.
It inhibits transport to the nucleus of the transcription factor NF-AT
- B.
It stimulates apoptosis of some lymphoid lineages
- C.
It decreases the activity of calcineurin
- D.
It inhibits mTOR, which in turn delays the G1—S transition
- E.
It inhibits proliferation of promyelocytes
Correct Answer
C. It decreases the activity of calcineurinExplanation
The answer is C. Tacrolimus decreases the activity of calcineurin, which leads to a decrease in nuclear NF-AT and the transcription of T-cell-specific lymphokines and early T-cell activation. Choice A refers to mechanism of action of cyclosporine. Choice B refers to glucocorticoids. Choice D represents the mechanism of action of sirolimus. Choice E refers to azathioprine.Rate this question:
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- 42.
Which of the following is an alkylating agent that may cause hemorrhagic cystitis and cardiomyopathy?
- A.
Azathioprine
- B.
Cyclosporine
- C.
Tacrolimus
- D.
Cyclophosphamide
- E.
Basiliximab
Correct Answer
D. CyclopHospHamideExplanation
The answer is D. Cyclophosphamide has been successfully used for treatment of lupus nephritis; however, it does carry significant morbidity associated with its use. Azathioprine works by suppressing T-cell activity (A). Cyclosporine inhibits T-helper cell activation (B). Tacrolimus inhibits transcription of T-cell-specific lymphokines (C). Baciliximab is a monoclonal antibody against CD-25 used to reduce the incidence and severity of renal transplant rejection.Rate this question:
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- 43.
Your resident asks you what the mechanism of action of tPA is. What is your answer?
- A.
It inhibits platelet aggregation
- B.
It increases antithrombin activity
- C.
It impairs inhibits fibrin polymerization
- D.
It blocks GPIIa/IIIb
- E.
It activates plasminogen bound to fibrin
Correct Answer
E. It activates plasminogen bound to fibrinExplanation
The answer is E. As the name suggests, tPA activates plasminogen bound to plasmin, thereby acting as a thrombolytic. Choice A refers to clopidogrel and ticlopidine. Choice B refers to heparin and its analogues. Choice C refers to dextran. Finally, choice D refers to abciximab.Rate this question:
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- 44.
Which of the following is an antidote for iron overdose?
- A.
Protamine
- B.
Deferoxamine
- C.
Vitamin K
- D.
Fresh frozen plasma
- E.
Charcoal
Correct Answer
B. DeferoxamineExplanation
The answer is B. Deferoxamine is an iron-chelating agent and as such can be given in cases of iron supplement overdose. Protamine (A) is an antidote for heparin. Vitamin K (C) and fresh frozen plasma (D) are given for coumarin reversal. Charcoal is an agent sometimes used for gastric lavage.Rate this question:
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- 45.
Which of the following medications would provide the best relief from episodic attacks of Ménìre's disease?
- A.
Furosemide
- B.
Ondansetron
- C.
Diazepam
- D.
Emetrol
- E.
Phentermine
Correct Answer
C. DiazepamExplanation
The answer is C. Diazepam and lorazepam are very effective at treating the vertigo associated with Ménìre's disease. Loop diuretics, such as furosemide, can precipitate vertigo secondary to volume depletion and resultant orthostatic hypotension. Ondansetron is a powerful antiemetic. Emetrol is an over-the-counter (OTC) antiemetic for infants. Phentermine is an amphetamine derivative that has been used for weight loss.Rate this question:
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- 46.
A 56-year-old female with severe rheumatoid arthritis returns to see her rheumatologist. She had been referred to a gastroenterologist, who had found multiple gastric ulcers on esophogastroduodenoscopy. She is reluctant to give up the use of NSAIDS and afraid of the potential cardiovascular toxicity of COX-2 inhibitor. At this point, what would be reasonable for the rheumatologist to prescribe?
- A.
Omeprazole
- B.
Lansoprazole
- C.
Nizatidine
- D.
Metronidazole
- E.
Misoprostol
Correct Answer
E. MisoprostolExplanation
The answer is E. Misoprostol is approved for use in patients taking NSAIDS, both to decrease acid production and to increase bicarbonate and mucous production. Both omeprazole and lansoprazole are proton inhibitors that would not increase the protective mucous and bicarbonate. Nizatidine is an H2-blocker that would also do nothing to increase the production of protective prostaglandins. Metronidazole is an antibiotic used to treat Helicobacter pylori.Rate this question:
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- 47.
A 29-year-old male who recently immigrated to the United States sees his physician for a burning sensation in his epigastrium. He is referred to a gastroenterologist, who performs esophogastroduodenoscopy with biopsy that demonstrate ulcers with the presence of Helicobacter pylori. Use of which of the following regimens would provide the most effective and shortest treatment?
- A.
Pepto Bismol, metronidazole, tetracycline, and omeprazole
- B.
Pepto Bismol, metronidazole, tetracycline, and ranitidine
- C.
Clathromycin, metronidazole, and omeprazole
- D.
Clathromycin, amoxicillin, and omeprazole
- E.
Pepto Bismol, metronidazole, and amoxicillin
Correct Answer
A. Pepto Bismol, metronidazole, tetracycline, and omeprazoleExplanation
The answer is A. Pepto Bismol, metronidazole, tetracycline, and omeprazole can be used for 7 days to eradicate Helicobacter pylori associated with peptic ulcer disease. Choice E (Pepto Bismol, metronidazole, and amoxicillin) was the original triple therapy. The use of a proton pump inhibitor is usually preferred to an H2-blocker, as in choice B. Regimens containing clathromycin are used for cases of resistance to metronidazole. All the choices except A require 14 days of treatment.Rate this question:
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- 48.
An 83-year-old male with multiple medical problems develops worsening constipation during his hospitalization for lower extremity cellulitis. The hospitalist decides to start giving a laxative. Which of the following is an appropriate choice and why?
- A.
Psyllium, because it is a bulk-forming laxative good for chronic constipation
- B.
An osmotic agent, such as senna, which is administered rectally
- C.
A stool softener such as lactulose administered rectally
- D.
A stool softener such as methyl cellulose that inhibits water reabsorption
- E.
A salt-containing osmotic agent such as docusate, useful in preventing constipation
Correct Answer
A. Psyllium, because it is a bulk-forming laxative good for chronic constipationExplanation
The answer is A. Psyllium and methyl cellulose are bulk-forming agents good for chronic constipation. The osmotic agent lactulose is given orally. Stool softeners such as docusate are useful in preventing constipation. Salt-containing osmotic agents such as magnesium sulfate are good for acute evacuation of the bowels. Senna is an irritant agent that stimulates intestinal motility.Rate this question:
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- 49.
A 35-year-old intravenous drug abuser in a methadone maintenance program is admitted to the hospital for a work-up of suspected pulmonary tuberculosis. While in the hospital, he complains of diarrhea and cramping. After stool studies return with a negative result, you decide to begin an antidiarrheal. Which of the following is a good choice for this patient?
- A.
Kaolin
- B.
Codeine
- C.
Diphenoxylate
- D.
Loperamide
- E.
Propantheline
Correct Answer
D. LoperamideExplanation
The answer is D. Loperamide would be a good choice in this patient as it effectively controls diarrhea. Both codeine and diphenoxylate are opioids with abuse potential, especially in patients with abusive histories. Diphenoxylate is available in combination with atropine to reduce the potential for abuse. Anticholinergics such as propantheline prevent cramping but have little effect on diarrhea. Kaolin is good for absorbing toxins from the intestines.Rate this question:
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- 50.
Which of the following would be an appropriate treatment to begin in a patient with Crohn's disease?
- A.
Glucocorticoids
- B.
Sulfasalazine
- C.
Bismuth subsalicylate
- D.
Octreotide
- E.
Loperamide
Correct Answer
A. GlucocorticoidsExplanation
The answer is A. Glucocorticoids are used in the management of moderate cases of Crohn's disease. 5-Amino salicylic acid (5-ASA) compounds such as sulfasalazine are used in mild cases of ulcerative colitis. Octreotide is used for diarrhea secondary to increased release of gastrointestinal hormones. Bismuth subsalicylate and loperamide can be used in the treatment of uncomplicated diarrhea.Rate this question:
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Mar 20, 2023Quiz Edited by
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Jan 02, 2010Quiz Created by
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