MEDICOLOGY: USMLE Pharmacology MCQS and Case Studies Solutions 68

Monday, March 28, 2022

USMLE Pharmacology MCQS and Case Studies Solutions 68

01. Ecothiophate (for ophthalmic actions) inhibits? 
A. Acetylcholinesterase
B. Catechol-O-methyltransferase (COMT)
C. DOPA decarboxylase
D. MonoamineOxidase
E. Tyrosine hydroxylase

Answer: 1. Acetylcholinesterase

02. In experimental studies, when anesthetized subjects are treated intravenously with drug X, they exhibit a large decrease in diastolic BP, a slight increase in systolic BP, and a marked increase in the heart rate. The pretreatment of the subjects with Propranolol blocks these effects. Drug X is most likely one of the following?
A. Acetylcholine
B. Epinephrine
C. Histamine
D. Isoproterenol
E. Norepinephrine

Answer: D. Isoproterenol

03. A 56-year-old patient is suffering from a markedly diminished interest in most daily activities, loss of energy, an inability to concentrate, and a feeling of worthlessness. Her physician prescribes an antidepressant. Three weeks after the patient begins taking the drug, she complains of insomnia and nervousness. Which of the following antidepressant drugs is most likely to cause the most recent symptoms?
A. Amoxapine
B. Clonazepam
C. Fluoxetine
D. Imipramine
E. Prazosin

Answer: C. Fluoxetine
04. A 65 years old man has episodes of sudden, repeated, lightning bursts of pain involving the upper part of the left side of his face. The pain is excruciating, with each burst lasting for a few seconds. Which of the following drug is the drug of choice for this disease?
A. Barbiturates
B. Carbamazepine
C. Local anesthetics
D. Non-opioid analgesics
E. Opioid analgesics

Answer: B. Carbamazepine

05. A 25 years old female is brought to the emergency room with an increase in heart rate, an increase in BP, mydriasis, behavioral excitation, aggressiveness, paranoia, and hallucinations. If these symptoms are attributed to a drug overdose, which one of the following drugs is responsible?
A. Amphetamine
B. Ethanol
C. Fentanyl
D. Flunitrazepam
E. Marijuana

Answer: A. Amphetamine

06. A habitual user of a schedule-controlled drug abruptly stops using it. Within 8 hours she becomes anxious, gets severe abdominal pain with diarrhea, and starts sweating profusely. The symptoms intensify over the next 12 hours and she develops a runny nose, lacrimation, uncontrolled yawning, and muscular cramping. Assuming that these are the withdrawal symptoms due to her physical dependence, the most likely drug to be involved is:
A. Alprazolam
B. Amphetamine
C. Ethanol
D. Meperidine
E. Secobarbital

Answer: D. Meperidine

07. A patient with CCF is being treated with a drug affecting the renal tubules. After continued use, he developed hyperkalemia. Which of the following drugs may be responsible for his condition?  
A. Acetazolamide
B. Chlorothiazide
C. Chlorthalidone
D. Ethacrynic acid
E. Spironolactone

Answer: E. Spironolactone
08. A 42-year-old diabetic female was advised a diuretic by a local physician to control her hypertension. After using the drug her blood sugar levels raised frequently and were not controlled by her prescribed antidiabetic drugs. Which of the following diuretics may cause an increase in blood sugar levels by interfering with the release of insulin from the beta cell of the pancreas?
A. Acetazolamide
B. Amiloride
C. Chlorothiazide
D. Spironolactone
E. Triamterene

Answer: C. Chlorothiazide

09. After taking a diuretic for a few days, prescribed by a local physician a 38-year-old comes with a painfully swollen toe and is diagnosed with acute gout. He gave a history of being treated for elevated uric acid levels. Which of the following drugs may have aggravated this condition?
A. Acetazolamide
B. Allopurinol
C. Furosemide
D. Spironolactone
E. Triamterene

Answer: C. Furosemide
10. A 45-year-old male takes pravastatin for hypercholesterolemia; however, his cholesterol level remains above target at maximal doses. Cholestyramine is added to the therapeutic regimen. What drug-drug interaction can occur?
A. Both will show a synergistic effect
B. Cholestyramine inhibits gastrointestinal (GI) absorption of pravastatin
C. Pravastatin is a direct antagonist of cholestyramine
D. The combination causes elevated very-low-density lipoprotein (VLDL)

Answer: B. Cholestyramine inhibits gastrointestinal (GI) absorption of pravastatin
11. A 45-year-old male, post-myocardial infarction (post-MI) for one week is being treated with intravenous (IV) heparin. Stool guaiac was negative when admitted,  but now it's 4+, and he has had an episode of hematemesis. The heparin is stopped & now a drug is given to stop the bleeding. What drug was given?
A. Aminocaproic acid
B. Dipyridamole
C. Factor IX
D. Protamine
E. Vitamin K

Answer: D. Protamine

12. A 45-year-old male experienced epigastric pain that begins a few hours after a meal and is often accompanied by acidic regurgitation. Treatment with aluminum hydroxide relieves his symptoms but causes adverse effects. The most common adverse effect of this type of antacid is:
A. Constipation
B. Diarrhea
C. Headache
D. Hypertension
E. Vomiting

Answer: A. Constipation
13. A 15-year-old girl is diagnosed with primary dysmenorrhea. She is being treated with ibuprofen to relieve headaches, fatigue, and severe cramping pain associated with her menstrual cycle. The patient is advised to call her physician to call if the drug causes gastrointestinal disturbances. Gastrointestinal effects induced by ibuprofen are mediated by:
A. Blockade of cholinergic receptors
B. Inhibition of acetylcholinesterase
C. Inhibition of cyclooxygenase-1
D. Inhibition of cyclooxygenase-2
E. Stimulation of motilin receptors

Answer: C. Inhibition of cyclooxygenase-1
14. A 33-year-old woman has severe constipation. She has a busy work schedule and says that she usually “eats something” on the run and often eats only a few candy bars a day and drinks coffee. Her physician prescribes a bulk-forming laxative. Which of the following is the most likely agent prescribed?
A. Aluminum hydroxide
B. Bismuth
C. Phenolphthalein
D. Psyllium
E. Sucralfate

Answer: D. Psyllium

15. Despite treatment, a 4-year-old boy with asthma has been suffering from wheezing attacks for 2 years. He was referred to a pulmonary clinic and he begins therapy with fluticasone, albuterol, and an inhaler. Fluticasone reduces lung inflammation by which of the following mechanisms?
A. Blockade of phospholipid breakdown
B. Blockade of triglyceride breakdown
C. Inhibition of cyclooxygenase
D. Inhibition of lipoxygenase
E. Inhibition of phosphodiesterase

Answer: A. Blockade of phospholipid breakdown
16. A 45-year-old male has severe persistent asthma with bronchial hyperactivity due to airway inflammation. His responsiveness to treatment with a variety of β2 – adrenergic receptor agonists has been decreasing. Therapy with which of the following immunosuppressive agents would most likely be recommended?
A. Azathioprine
B. Cyclophosphamide
C. Cyclosporine
D. Flunisolide
E. Methotrexate

Answer: D. Flunisolide
17. A 26-year-old woman is infected simultaneously with Treponema Pallidum, Neisseria gonorrhea, and Chlamydia trachomatis. Which of the following drugs would be most effective against all three of these sexually transmitted diseases?
A. Ampicillin
B. Cephalexin
C. Doxycycline
D. Penicillin G
E. Streptomycin

Answer: C. Doxycycline

18. A 48-year-old man is brought to the hospital in a coma. The medical record indicates that he has a long history of liver cirrhosis and signs of mental impairment. He has been treated previously for esophageal varices and ascites. The physician administers an antibiotic that will sterilize the patient’s intestinal tract and thereby reduce the burden of toxic substances absorbed from the intestine. Which of the following drugs would be most appropriate without placing the patient at risk of drug toxicity? 
A. Ampicillin
B. Chloramphenicol
C. Clindamycin
D. Neomycin
E. Nystatin

Answer: D. Neomycin
19. A 27-year-old who has AIDS reports for a regular checkup and complains of headache and difficulty with eye-hand coordination. He is found to have cerebral toxoplasmosis but there is no evidence of Pneumocystis jirovecii. The most appropriate treatment for this patient is with?
A. Mebendazole
B. Mefloquine
C. Praziquantel
D. Pyrimethamine plus sulfadiazine
E. Trimethoprim plus sulfamethoxazole

Answer: D. Pyrimethamine plus sulfadiazine
20. A neonate is found to have meningitis due to Haemophilus influenza. Treatment with an improper dosage of which of the following drugs would place the patient at risk of “Gray baby” syndrome?
A. Amoxicillin
B. Chloramphenicol
C. Clindamycin
D. Gentamycin
E. Tetracycline

Answer: B. Chloramphenicol

21. A 3-year-old-girl is taken to the emergency department because she has had a temperature of 39° C for 7 hours, is drooling, has difficulty breathing, and is making noisy expiratory sounds. Examination shows a swollen epiglottis and cherry red throat. Which of the following antimicrobials would be the most appropriate for empiric parenteral therapy?
A. Ceftriaxone
B. Cephalexin
C. Chloramphenicol
D. Penicillin G
E. Vancomycin

Answer: A. Ceftriaxone

22. A 30-year-old man with AIDS is diagnosed with advanced cavity tuberculosis. Which of the following treatments would be most effective in the management of the patient’s T.B?
A. Isoniazid plus cycloserine
B. Isoniazid plus ethambutol
C. Isoniazid plus pyrazinamide plus rifampin
D. Pyrazinamide plus streptomycin
E. Rifampin plus cycloserine

Answer: C. Isoniazid plus pyrazinamide plus rifampin
23. A 24-year-old woman complains of itching and redness around the pelvic area and says that the symptoms are most intense during the night. Examination shows the presence of Phthisis pubis. Which of the following drug will eradicate the infestation?
A. Mebendazole
B. Metronidazole
C. Permethrin
D. Praziquantel
E. Tetracycline

Answer: C. Permethrin

24. A 33-year-old patient with AIDS has a history of numerous opportunistic infections. He experiences a sudden decrease in visual acuity and is found to have a reduced field of vision. Funduscopic examination shows a typical picture of retinochoroiditis caused by Cytomegalovirus (CMV), and serologic evaluation confirms the diagnosis. Which of the following drugs is most appropriate for initial treatment?
A. Amphotericin B
B. Foscarnet
C. Gentamicin
D. Hydrocortisone
E. Vidarabine

Answer: B. Foscarnet
25. Estrogen receptor-positive tumor cells are detected in a 54-year-old postmenopausal woman with breast cancer. Which of the following would act by blocking estrogen receptors in her breast tissue?
A. Levonorgestrel
B. Nafarelin
C. Octreotide
D. Sermorelin
E. Tamoxifen

Answer: E. Tamoxifen
26. The “minipill” containing only progestin, rather than a combination estrogen-progestin oral contraceptive, was developed because of progestin alone:
A. Is a more effective contraceptive drug as compared to two combined
B. Because it's less likely to induce cardiovascular (CVS) disorders
C. Is thought to be less likely to induce endometriosis
D. Results in a more regular menstrual cycle
E. Results in less depression and cholestatic jaundice

Answer: B. Because it's less likely to induce cardiovascular (CVS) disorders

27. Which of the following is an H2-receptor antagonist?
A. Cimetidine
B. Cyproheptadine
C. Fluoxetine
D. Ondansetron
E. Sumatriptan

Answer: A. Cimetidine

No comments:

Post a Comment