Test your basic knowledge |

USMLE Step 1 Pharmacology

Subjects : health-sciences, usmle-step-1

Instructions:

Answer 50 questions in 15 minutes.
If you are not ready to take this test, you can study here.
Match each statement with the correct term.
Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.

1. Why is carbachol and pilocarpine useful in treatment of glaucoma?
Aluminum sucrose sulfate polymerizes in the acid environment of the stomach and selectively binds necrotic peptic ulcer tissue. Acts as a barrier to acid - pepsin - and bile.
Activates cholinergic receptors on bladder and bowel smooth muscle - alleviating post - op and neurogenic ileus and urinary retention.
They activate the ciliary muscle of the eye (open angle) and pupillary sphincter (narrow angle).
- Niacin - Ca++ channel blockers - adenosine - vancomycin

2. What are four unwanted effects of Clomiphene use?
Prevents release of mediators from mast cells. Effective only for the prophylaxis of asthma. Not effective during an acute attack.
Binds ergosterol - Disrupts fungal membranes
1. Hot flashes 2. Ovarian enlargement 3. Multiple simultaneous pregnancies 4. Visual disturbances
hypertension - CHF - diabetic renal disease

3. What is the effect of norepinephrine on bp and pulse pressure?
not a sulfonamide - but action is the same as furosemide
blocks SR Ca2+ channels
decrease myocardial O2 consumption by: 1- decreasing end diastolic volume 2- decreasing BP 3- decreasing HR 4- decreasing contractility 5- decreasing ejection time
Increases mean - systolic - and diastolic bp - while there is little change in pulse pressure.

4. What are five disadvantages of Oral Contraceptives (synthetic progestins - estrogen)?
1. Taken daily 2. No protection against STDs 3. Raises triglycerides 4. Depression - weight gain - nausea - HTN 5. Hypercoagulable state
AmOxicillin has greater Oral bioavailability
- reduction - oxy - & hydrolysis - H2O sol. Polar product - P450
Botulinum

5. What are the products and their toxicities of the metabolism of Ethylene Glycol by / alcohol dehydrogenase?
Pentamidine
- Oxalic acid - Acidosis & nephrotoxicity
YES
Succinylcholine

6. List the mechanism - clinical use - & toxicity of Doxorubicin.

Warning: Invalid argument supplied for foreach() in /var/www/html/basicversity.com/show_quiz.php on line 183

7. Mannitol - clinical use?
Irreversibly inhibits H+/K+ ATPase in stomach parietal cells.
ARF - shock - drug overdose - decrease intracranial/intraocular pressure
Inhibits DNA dependent RNA polymerase
Digitoxin 70% Digoxin 20-40%

8. Will Hemicholinum affect the release of stored Ach during Cholinergic Stimulation
Blocks viral penetration/uncoating; may act to buffer the pH of the endosome
No - hemicholinum block the uptake of Choline and thus Ach synthesis
Similar to cyclosporine; binds to FK- binding protein - inhibiting secretion of IL-2 and other cytokines.
Spironolactone - Triamterene - Amiloride (the K+ STAys)

9. Resistance mechanisms for Chloramphenicol
- ED 50 is less than the Km (less than 50% of receptors)
Inhibits bacterial Dihydrofolate Reductase - Bacteriostatic
Modification via Acetylation
YES

10. Name two bile acid resins.
cholestyramine - colestipol
distal convoluted tubule (early)
effective in torsade de pointes and digoxin toxicity
The only local anesthetic with vasoconstrictive properties.

11. What are five advantages of Oral Contraceptives (synthetic progestins - estrogen)?
1. Bleeding 2. Teratogenicity 3. Drug - drug interactions
distal convoluted tubule (early)
Prevents the release of Ca from SR of skeletal muscle
1. Reliable (<1% failure) 2. Lowers risk of endometrial and ovarian cancer 3. Decreased incidence of ectopic pregnancy 4. Lower risk of pelvic infections 5. Regulation of menses

12. What is a possible toxicity of Ticlopidine - Clopidogrel usage?
Potent immunosuppressive used in organ transplant recipients.
Diuresis in pateints with sulfa allergy
Neutropenia (ticlopidine); reserved for those who cannot tolerate aspirin.
1. Bleeding 2. Teratogenicity 3. Drug - drug interactions

13. How is Ganciclovir used clinically?
Pralidoxime regenerates active cholinesterase.
Praziquantel
CMV - esp in Immunocompromised patients
hypokalemia - slight hyperlipidemia - hyperuricemia - lassitude - hypercalcemia - hyperglycemia

14. K+ sparing diuretics - toxicity?
Meningitis (H. influenza - N. meningitidis - S. pneumoniae) - Conserative treatment due to toxicities
Tubocurarine - atracurium - mivacurium - pancuronium - vecuronium - rapacuronium
hyperkalemia - endocrine effects (gynecomastia - anti - androgen)
1. Buffalo hump 2. Moon facies 3. Truncal obesity 4. Muscle wasting 5. Thin skin 6. Easy bruisability 7. Osteoporosis 8. Adrenocortical atrophy 9. Peptic ulcers

15. List the specific antidote for this toxin: Digitalis
- Normalize K+ - Lidocaine - & Anti - dig Mab
- Vinca alkaloids(inhibit MT) - Paclitaxel
anuria - CHF
- ED 50 is less than the Km (less than 50% of receptors)

16. What is the formula for Clearance (CL)
DOC in diagnosing and abolishing AV nodal arrhythmias
CL= (rate of elimination of drug/ Plasma drug conc.)
Cilastatin
Mg = Must go to the bathroom.

17. MOA of Succinylcholine
- Alkalates DNA - CML - Pulmonary fibrosis hyperpigmentation
Prevents release of mediators from mast cells. Effective only for the prophylaxis of asthma. Not effective during an acute attack.
Gram + cocci - Gram - rods - and Anerobes
Prevents the release of Ca from SR of skeletal muscle

18. MOA: Disrupt bacterial/fungal cell membranes
Digitoxin 70% Digoxin 20-40%
Blocks translocation - binds to the 23S rRNA of the 50S subunit - Bacteriostatic
Amphotericin B - Nystatin - Fluconazole/azoles
Polymyxins

19. What is the mechanism of action of Misoprostol?
1. Skin rash 2. Agranulocytosis (rare) 3. Aplastic anemia
Misoprostol is a PGE1 analog that increases the production and secretion of the gastic mucous barrier.
Cell membrane Ca2+ channels of cardiac sarcomere
Inhibits organification and coupling of thyroid hormone synthesis. Also decreases peripheral conversion of T4 to T3.

20. For Warfarin What is the Lab value to monitor
Gram + - Gram - - Norcardia - Chlamydia
sedation - depression - nasal stuffiness - diarrhea
Phase 1 = prolonged depolarization - no antidote - effect potentiated by anticholinesterase; Phase 2 = repolarized but blocked - an anticholinesterase is the antidote for this phase.
PT

21. How can the t1/2 of INH be altered?
Fast vs. Slow Acetylators
GI distress - Skin rash - and Seizures at high plasma levels
Cryptococcal meningitis in AIDS patients and Candidal infections of all types
Cimetidine is a potent inhibitor of P450; it also has an antiandrogenic effect and decreases renal excretion of creatinine. Other H2 blockers are relatively free of these effects.

22. What are the products and their toxicities of the metabolism of Methanol by / alcohol dehydrogenase?
Hormone synthesis inhibition (Gynecomastia) - Liver dysfunction (Inhibits CYP450) - Fever - Chills
They inhibit reuptake of NE at the nerve terminal (as does cocaine).
- Formaldehyde & formic acid - severe acidosis & retinal damage
constipation - flushing - edema - CV effects (CHF - AV block - sinus node depression) - and torsade de pointes (Bepridil)

23. For Heparin What is the Lab value to monitor
Chronic anticoagulation.
fetal renal toxicity - hyperkalemia
Benzathine penicillin G
aPTT (intrinsic pathway)

24. What parasites are treated with Pyrantel Pamoate (more specific)?
- Alkalate DNA - Brain tumors - CNS toxicity
- Barbiturates - phenytoin - carbamazipine - rifampin - griseofulvin - quinidine
Giant Roundworm (Ascaris) - Hookworm (Necator/Ancylostoma) - Pinworm (Enterobius)
Rash - Pseudomembranous colitis

25. What is the clincial use for Misoprostol?
Prevention of NSAID- induced peptic ulcers - maintains a PDA.
Hypersensitivity reactions
all except the K+ sparing diuretics Spironolactone - Triamterene - Amiloride
- Formaldehyde & formic acid - severe acidosis & retinal damage

26. What are four clinical activities of Aspirin?
Malaria (P. falciparum)
Na/K ATPase
Hemicholinium inhibits the transport of choline into the nerve - thus inhibiting formation of ACh.
1. Antipyretic 2. Analgesic 3. Anti - inflammatory 4. Antiplatelet drug.

27. What are two toxicities of the Sulfonylureas?
Can affect absorption - bioavailability - or urinary excretion of other drugs by altering gastric and urinary pH or by delaying gastric emptying.
Milk or Antacids - because divalent cations inhibit Tetracycline absorption in the gut
Blastomyces - Coccidioides - Histoplasma - C. albicans; Hypercortisolism
1. Hypoglycemia (more common with 2nd - generation drugs: glyburide - glipizide) 2. Disulfiram - like effects (not seen with 2nd - generation drugs).

28. What are common serious side effects of Aminoglycosides and What are these associated with?
Initially vasoconstriction would increase bp - but then it acts on central alpha -2 receptors to decrease adrenergic outflow resulting in decreased bp.
Nephrotoxicity (esp. with Cephalosporins) - Ototoxicity (esp. with Loop Diuretics)
Liver
Large anionic polymer - acidic

29. Which of the following would atropine administration cause? Hypothermia - bradycardia - excess salivation - dry flushed skin - or diarrhea
cardiac muscle: Verapamil>Diltiazem>Nifedipine
HTN - CHF - calcium stone formation - nephrogenic DI.
- Clindamycin
Dry flushed skin - due to inhibition of sympathetic post - ganglionic blockade on muscarinic receptors of sweat glands. All others are opposite of What would be expected.

30. MOA: Block peptidoglycan synthesis
distal convoluted tubule (early)
Lidocaine - Mexiletine - Tocainide
Warfarin interferes with the normal synthesis and gamma - carboxylation of vitamin K- dependent clotting factors II - VII - IX - and X - Protein C and S via vitamin K antagonism.
Bacitracin - Vancomycin

31. Adverse effects of beta - blockers?
cortical collecting tubule
Babiturate.
Rifampin - Ethambutol - Streptomycin - Pyrazinamide - Isoniazid (INH)
impotence - asthma - CV effects (bradycardia - CHF - AV block) - CNS effects (sedation - sleep alterations)

32. How is Amantadine used clinically?

Warning: Invalid argument supplied for foreach() in /var/www/html/basicversity.com/show_quiz.php on line 183

33. Which diuretics increase urine K+?
severe orthostatic hypotension - blurred vision - constipation - sexual dysfunction
Gemfibrozil - Clofibrate
all except the K+ sparing diuretics Spironolactone - Triamterene - Amiloride
- Physostigmine salicylate

34. Antimicrobial prophylaxis for Gonorrhea
Ceftriaxone
1. Skin rash 2. Agranulocytosis (rare) 3. Aplastic anemia
- acetylation - glucuron. - & sulfation - Conjugation - Polar product
- Isoniazid

35. How do you calculate maintenance dose?
Beta 2 agonist; desired effect is the relaxation of bronchial smooth muscle (Beta 2). Use during acute exacerbation.
Md= (CpxCL)/F Cp= plas. Conc. CL=clear. F=bioaval.
When pts have Low CD4+ (< 500 cells/cubic mm) or a High Viral Load
Megaloblastic anemia - Leukopenia - Granulocytopenia

36. Name the common Nucleoside Reverse Transcriptase Inhibitors
Activates cholinergic receptors on bladder and bowel smooth muscle - alleviating post - op and neurogenic ileus and urinary retention.
Zidovudine (AZT) - Didanosine (ddI) - Zalcitabine (ddC) - Stavudine (d4T) - Lamivudine (3TC)
Cestode/tapeworm (e.g. - D. latum - Taenia species Except Cysticercosis
Praziquantel

37. Which drug(s) cause this reaction: Pulmonary fibrosis(3)?
Anaerobic infections (e.g. - B. fragilis - C. perfringens)
- Bleomycin - amiodarone - busulfan
Systemic mycoses
Acts as a wide spectrum carbapenem

38. Isopoterenol was given to a patient with a developing AV block - why?
Oxygen
Stimulates beta adrenergic receptors
1. Cimetadine 2. Ranitidine 3. Famotidine 4. Nizatidine
- Methotrexate - 5 FU - 6 mercaptopurine

39. How are Interferons (INF) used clinically?

Warning: Invalid argument supplied for foreach() in /var/www/html/basicversity.com/show_quiz.php on line 183

40. MOA: Bactericidal antibiotics
reversible SLE- like syndrome
1. Hydrocortisone 2. Predisone 3. Triamcinolone 4. Dexamethasone 5. Beclomethasone
Ipratropium
Penicillin - Cephalosporins - Vancomycin - Aminoglycosides - Fluoroquinolones - Metronidazole

41. Toxic side effects of the Azoles?
Antileukotriene; blocks synthesis by lipoxygenase.
Hormone synthesis inhibition (Gynecomastia) - Liver dysfunction (Inhibits CYP450) - Fever - Chills
Wide spectrum of systemic mycoses: Cryptococcus - Blastomyces - Coccidioides - Aspergillus - Histoplasma - Candida - Mucor
Aminoglycosides - Tetracyclines

42. Why are Methicillin - Nafcillin - and Dicloxacillin penicillinase resistant?
When pts have Low CD4+ (< 500 cells/cubic mm) or a High Viral Load
Due to the presence of a bulkier R group
Systemic mycoses
1. Antipyretic 2. Analgesic 3. Anti - inflammatory

43. What are toxic side effects for Metronidazole?
Disulfiram - like reaction with EtOH - Headache
ARF - shock - drug overdose - decrease intracranial/intraocular pressure
Centrally acting alpha agonist - thus causing a decrease in central adrenergic outflow - spairing renal blood flow
1. Infertility (pulsatile) 2. Prostate cancer (continuous: use with flutamide) 3. Uterine fibroids

44. Name the common Non - Nucleoside Reverse Transcriptase Inhibitors
Nevirapine - Delavirdine
- Chloramphenicol
Staphlococcus aureus and Clostridium difficile (pseudomembranous colitis)
CMV Retinitis in IC pts When Ganciclovir fails

45. Which RT inhibitors cause Lactic Acidosis?
Ibuprofen - Naproxen - and Indomethacin
Penicillin - Ampicillin - Ticarcillin - Pipercillin - Imipenem - Aztreonam - Cephalosporins
Nucleosides
Methylation of rRNA near Erythromycin's ribosome binding site

46. Decrease Digitoxin dose in renal failure?
1. Streptokinase 2. Urokinase 3. tPA (alteplase) - APSAC (anistreplase)
- NaHCO3
- EDTA - dimercaprol - succimer - & penicillamine
NO

47. What is combined with Ampicillin - Amoxicillin - Carbenicillin - Piperacillin - and Ticarcillin to enhance their spectrum?
hypokalemia - slight hyperlipidemia - hyperuricemia - lassitude - hypercalcemia - hyperglycemia
Clavulanic acid
Hemolysis (if G6PD deficient) - Neurotoxicity - Hepatotoxicity - SLE- like syndrome
- Sulfonamides - INH - ASA - Ibuprofen - primaquine - nitrofurantoin /- pyrimethamine - chloramphenicol

48. Name three Antiarrhythmic drugs in class IC.
Inhibits cell wall synthesis ( binds to PBP3). A monobactam
Flecainide - Encainide - Propafenone
The COX-2 inhibitors should not have the corrosive effects of other NSAIDs on the gastrointestinal lining.
1. Pioglitazone 2. Rosiglitazone.

49. How is Amphotericin B used clinically?
Wide spectrum of systemic mycoses: Cryptococcus - Blastomyces - Coccidioides - Aspergillus - Histoplasma - Candida - Mucor
GnRH analog with agonist properties When used in pulsatile fashion and antagonist properties When used in continuous fashion - causing a transient initial burst of LH and FSH
sedation - sleep alterations
Hypokalemic metabolic alkalosis - hyponatremia - hyperGlycemia - hyperLipidemia - hyperUricemia - hyperCalcemia - sulfa allergy.

50. How would you reverse the effect of a neuromuscular blocking agent?
Rifampin
1. Peptic ulcer 2. Gastritis 3. Esophageal reflux 4. Zollinger - Ellison syndrome
Give an antichloinesterase - neostigmine - edrophonium - etc
Inhibits platelet aggregation by irreversibly inhibiting the ADP pathway involved in the binding of fibrinogen.