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USMLE Step 1 Pharmacology

Subjects : health-sciences, usmle-step-1

Instructions:

Answer 50 questions in 15 minutes.
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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. Preferential action of the Ca2+ channel blockers at cardiac muscle?
Aplastic anemia (dose independent) - Gray Baby Syndrome
anticholinesterase glaucoma
Cryptococcal meningitis in AIDS patients and Candidal infections of all types
cardiac muscle: Verapamil>Diltiazem>Nifedipine

2. ACE inhibitors - clinical use?
DOC in diagnosing and abolishing AV nodal arrhythmias
1. RNA pol inhibitor 2. Revs up P450 3. Red/orange body fluids 4. Rapid resistance if used alone
hypertension - CHF - diabetic renal disease
Bleeding.

3. List the specific antidote for this toxin: Amphetamine
Yes - it does not cross the placenta.
Rifampin - Ethambutol - Streptomycin - Pyrazinamide - Isoniazid (INH)
Clavulanic acid
- Ammonium Chloride

4. What is the difference between the affinity for beta receptors between albuterol/terbutaline and dantroline?
Protease Inhibitors and Reverse Transcriptase Inhibitors
Reserpine inhibits dopamine transport into vesicles - attenuating its conversion to NE by dopamine beta - hydroxylase.
Dobutamine has more of an affintiy for beta -1 than beta -2 - and is used for treating heart failure and shock. Albuterol and terbutaline is the reverse - and is used in treatment of acute asthma.
TMP- SMZ

5. Which drug(s) cause this reaction: Atropine - like side effects?
- Haloperidol - chlorpromazine - reserpine - MPTP
- Tricyclic antidepressants
carbonic anhydrase inhibitors - K+ sparing diuretics
- inhibits HGPRT (pur. Syn.) - Luk - Lymph

6. What are two indirect acting adrenergic agonists?
amphetamine and ephedrine
blocks SR Ca2+ channels
Because they require some residual islet function.
Cestode/tapeworm (e.g. - D. latum - Taenia species Except Cysticercosis

7. Antimicrobial prophylaxis for Gonorrhea
Ipratropium
Anaerobic infections (e.g. - B. fragilis - C. perfringens)
1. Heavy bleeding 2. GI effects (n/v - anorexia) 3. Abdominal pain
Ceftriaxone

8. What is the effect of epinephrine infusion on bp and pulse pressure?
Increased systolic and pulse pressure - decreased diastolic pressure - and little change in mean pressure.
Hemolysis (if G6PD deficient) - Neurotoxicity - Hepatotoxicity - SLE- like syndrome
Diarrhea - Urination - Miosis - Bronchospasm - Bradycardia - Excitation of skeletal muscle and CNS - Lacrimation - Sweating - and Salivation = DUMBBELS; also abdominal cramping
Beta -2 agonist.

9. Are Ampicillin and Amoxicillin are not...
Resistant Gram - infections
As an anticholinesterase it increases endogenous ACh and thus increases strength.
decrease AP duration - affects ischemic or depolarized Purkinje and ventricular system
penicillinase resistant

10. How does dantrolene work?
Quinidine - Amiodarone - Procainamide - Disopyramide
Acute gout.
Prevents the release of calcium from the sarcoplasmic reticulum of skeletal muscle.
aPTT (intrinsic pathway)

11. Loop diuretics (furosemide)- site of action?
thick ascending limb
hypertension - angina - arrhythmias
- polymyxins
Hemolytic anemia

12. What are nine findings of Iatrogenic Cushing's syndrome caused by glucocorticoid therapy?
Verapamil - Diltiazem - Bepridil
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
- Ethosuxamide - sulfonamides - lamotrigine
Blastomyces - Coccidioides - Histoplasma - C. albicans; Hypercortisolism

13. For Warfarin What is the Ability to inhibit coagulation in vitro
Babiturate.
Treatment of infertility.
No
Antifungal.

14. What are the products and their toxicities of the metabolism of ethanol by / alcohol dehydrogenase?
Oxygen
- Acetaldehyde - Nausea - vomiting - headache - & hypotension
Receptors = D1=D2>beta>alpha - thus increasing heart rate (beta) and blood pressure (alpha vasoconstriction) while maintaining kidney perfusion (dopamine receptors)
collecting ducts

15. Classes of antihypertensive drugs?
Atropine pts are suffering from Cholinestrase inhibitor poisining (Nerve gas/Organophosphate poisining)
- Hydralazine - Procainamide - INH - phenytoin
diuretics - sympathoplegics - vasodilators - ACE inhibitors - Angiotensin II receptor inhibitors
Competitive inibitor of progestins at progesterone receptors.

16. What is used to reverse the action of Heparin?
1. Bleeding 2. Thrombocytopenia 3. Drug - drug interactions
Protamine Sulfate is used for rapid reversal of heparinization (positively charged molecule that binds to negatively charged heparin).
anuria - CHF
Norepinephrine

17. What are two toxicities of the Glitazones?
Beta1 more than B2
Inhibit Ergosterol synthesis
Digitoxin 168hrs Digoxin 40 hrs
1. Weight gain 2. Hepatotoxicity (troglitazone)

18. List the mechanism - clinical use - & toxicity of 6 MP.
Chronic (weeks or months)
Digitoxin 168hrs Digoxin 40 hrs
- inhibits HGPRT (pur. Syn.) - Luk - Lymph
hyperaldosteronism - K+ depletion - CHF

19. For Heparin What is the Structure
Diarrhea
Large anionic polymer - acidic
Resistant Gram - infections
narcolepsy - obesity - and attention deficit disorder (I wouldn't recommend this)

20. Ca2+ channel blockers - toxicity?
cardiac depression - peripheral edema - flushing - dizziness - constipation
Doxycycline - because it is fecally eliminated
Beta - lactam antibiotics
Phosphorylation by a Viral Kinase

21. What is the major side effect for Ampicillin and Amoxicillin?
Hypersensitivity reactions
- Phase I (clinical tests) - Phase II - Phase III - PhaseIV (surveillance)
- Antipsychotics
1. Renal damage 2. Aplastic anemia 3. GI distress

22. ACE inhibitors - toxicity?
Give an antichloinesterase - neostigmine - edrophonium - etc
Hemolysis (if G6PD deficient) - Neurotoxicity - Hepatotoxicity - SLE- like syndrome
fetal renal damage - hyperkalemia - Cough - Angioedema - Proteinuria - Taste changes - hypOtension - Pregnancy problems - Rash - Increased renin - Lower Angiotensin II (CAPTOPRIL)
Inhibits reabsorption of uric acid.

23. Which of epi - norepi - or isoproterenol results in bradycardia?
1) Hypersensitivity reactions 2) Increased nephrotoxicity of Aminoglycosides 3) Disulfiram - like reaction with ethanol (those with a methylthiotetrazole group - e.g. - cefamandole)
Norepinephrine
anuria - CHF
severe hypertension - CHF

24. Name several common Macrolides (3)
Erythromycin - Azithromycin - Clarithromycin
Diarrhea
Blocks translocation - binds to the 23S rRNA of the 50S subunit - Bacteriostatic
IV vitamin K and fresh frozen plasma

25. What is the lab value used to monitor the effectiveness of Heparin therapy?
Suramin
Aminoglycosides
The PTT.
Slow - limited by half lives of clotting factors

26. List the specific antidote for this toxin: Digitalis
1. Bleeding 2. Thrombocytopenia 3. Drug - drug interactions
- Normalize K+ - Lidocaine - & Anti - dig Mab
impotence - exacerbation of asthma - CV effects - CNS effects - may mask hypoclycemia
Methylxanthine.

27. List the specific antidote for this toxin: Benzodiazepines
- Flumazenil
alpha -1 > alpha -2; used as a pupil dilator - vasoconstrictor - and for nasal decongestion
- Chlorpromazine - thioridazine - haloperidol
Norepinephrine

28. What drug is used to diagnose myasthenia gravis?
GI upset
- Ethosuxamide - sulfonamides - lamotrigine
edrophonium (extremely short acting anticholinesterase)
- Alkalating agent - NHL - Breast - ovary - & lung. - Myelosuppression - & hemorrhagic cystitis.

29. Which diuretics decrease urine Ca2+?
competitive inhibirot of aldosterone in the cortical collecting tubule
impotence - asthma - CV effects (bradycardia - CHF - AV block) - CNS effects (sedation - sleep alterations)
thiazides - amiloride
- S- phase anti - metabolite Pyr analogue - Colon - solid tumors - & BCC/ - Irreversible myelosuppression

30. Are not penicillinase resistant
Carbenicillin - Piperacillin - and Ticarcillin
Leukotrienes increasing bronchial tone.
Vd= (Amt. of drug in body/ Plasma drug conc.)
1. Hypoglycemia (more common with 2nd - generation drugs: glyburide - glipizide) 2. Disulfiram - like effects (not seen with 2nd - generation drugs).

31. What drugs target anticholinesterase
anuria - CHF
Neostigmine - pyridostigmine edrophonium - physostigmine echothiophate
Pentamidine
1. Tolbutamide 2. Chlorpropamide 3. Glyburide 4. Glipizide

32. Can Warfarin be used during pregnancy?
No - warfarin - unlike heparin - can cross the placenta.
Beta 2 agonist; used as a long - acting agent for prophylaxis. Adverse effects are tremor and arrhythmia.
1. Cimetadine 2. Ranitidine 3. Famotidine 4. Nizatidine
constipation - flushing - edema - CV effects (CHF - AV block - sinus node depression) - and torsade de pointes (Bepridil)

33. List the specific antidote for this toxin: Opioids
- B51Naloxone / naltrexone (Narcan)
Selectively inhibit cyclooxygenase (COX) isoform 2 - Which is found in inflammatory cells nad mediates inflammation and pain; spares COX-1 Which helps maintain the gastric mucosa.
- Ethosuxamide - sulfonamides - lamotrigine
Recurrent UTIs - Shigella - Salmonella - Pneumocystis carinii pneumonia

34. What is the category of drug names ending in - olol (e.g. Propranolol)
Constant FRACTION eliminated per unit time.(exponential)
- Vinca alkaloids(inhibit MT) - Paclitaxel
YES
Beta antagonist.

35. How does Ganciclovir's toxicity relate to that of Acyclovir?
Ganciclovir is more toxic to host enzymes
scopolamine
With supplemental Folic Acid
They activate the ciliary muscle of the eye (open angle) and pupillary sphincter (narrow angle).

36. Antiarrhythmic class II- toxicity?
1. Pioglitazone 2. Rosiglitazone.
They inhibit reuptake of NE at the nerve terminal (as does cocaine).
cyanide toxicity (releases CN)
impotence - exacerbation of asthma - CV effects - CNS effects - may mask hypoclycemia

37. Antiarrhythmic class IV- primary site of action?
Pseudomembranous colitis (C. difficile) - fever - diarrhea
Penicillin.
AV nodal cells
Binds to the Pyrophosphate Binding Site of the enzyme

38. Antiarrhythmic class IC- effects?
NO AP duration effect. useful in V- tach that progresses to V- fib and in intractable SVT Last RESORT
Enterobacter
fetal renal toxicity - hyperkalemia
Misoprostol is contraindicated in women of childbearing potential because it is an abortifacient.

39. Hydrochlorothiazide - clinical use?
Blocks viral penetration/uncoating; may act to buffer the pH of the endosome
- Atropine & pralidoxime
troponin - tropomyosin system
HTN - CHF - calcium stone formation - nephrogenic DI.

40. Why would you use pralidoxime after exposure to an organophosphate?
Prevents the release of ACh - Which results in muscle paralysis.
Pralidoxime regenerates active cholinesterase.
osmotic diuretic - increase tubular fluid osmolarity - thereby increasing urine flow
Treatment of infertility.

41. What is a common side effect of Misoprostol?
Diarrhea
Misoprostol is contraindicated in women of childbearing potential because it is an abortifacient.
INH: Injures Neurons and Hepatocytes
1)Binds penicillin - binding proteins 2) Blocks transpeptidase cross - linking of cell wall 3) Activates autolytic enzymes

42. What do Aminoglycosides require for uptake?
Oxygen
CMV Retinitis in IC pts When Ganciclovir fails
Mycobacterium tuberculosis - the only agent used as solo prophylaxis against TB
reduce levels of Angiotensin II - thereby preventing the inactivation of bradykinin (a potent vasodilator); renin level is increased

43. Which RT inhibitors cause a Rash?
- Bleomycin - amiodarone - busulfan
Non - Nucleosides
- Estrogen receptor antagonist - Breast CA - increased endometrial CA risk
- NaHCO3

44. What are common side effects of Amphotericin B?
- Barbiturates - phenytoin - carbamazipine - rifampin - griseofulvin - quinidine
Beta 2 agonist; desired effect is the relaxation of bronchial smooth muscle (Beta 2). Use during acute exacerbation.
Fever/Chills - Hypotension - Nephrotoxicity - Arrhythmias
- Quinidine - quinine

45. What is the category - method of use - and adverse effects of Salmeterol in Asthma treatment?
Ibuprofen - Naproxen - and Indomethacin
Staphlococcus aureus and Clostridium difficile (pseudomembranous colitis)
Blastomyces - Coccidioides - Histoplasma - C. albicans; Hypercortisolism
Beta 2 agonist; used as a long - acting agent for prophylaxis. Adverse effects are tremor and arrhythmia.

46. Mannitol - toxicity?
Rifampin - Ethambutol - Streptomycin - Pyrazinamide - Isoniazid (INH)
G6PD deficient individuals
pulmonary edema - dehydration
Stimulating beta receptors stimulates heart rate - but beta receptor induced vasodilation reduces peripheral resistance.

47. How can the t1/2 of INH be altered?
- Oxalic acid - Acidosis & nephrotoxicity
Ibuprofen - Naproxen - and Indomethacin
Fast vs. Slow Acetylators
very short acting

48. What are three types of antacids and the problems that can result from their overuse?
effective in torsade de pointes and digoxin toxicity
As an anticholinesterase it increases endogenous ACh and thus increases strength.
1. Aluminum hydroxide: constipation and hypophosphatemia 2. Magnesium hydroxide: diarrhea 3. Calcium carbonate: Hypercalcemia - rebound acid increase - All may cause hypokalemia
fetal renal toxicity - hyperkalemia

49. What is the MOA of Foscarnet?
Bacitracin - Vancomycin
To inhibit renal Dihydropeptidase I and decrease Imipenem inactivation in the renal tubules
Inhibits Viral DNA polymerase
These B-2 agonists cause respiratory smooth muscle to relax.

50. List the mechanism - clinical use - & toxicity of Nitrosureas.
Atropine would also block the receptors in the ciliary muscle - causing an impairment in accommodation (cycloplegia).
NE increases bp - Which stimulates baroreceptors in the carotid sinus and the aorta. The CNS signals through vagal stimulation to decrease heart rate.
Diuresis in pateints with sulfa allergy
- Alkalate DNA - Brain tumors - CNS toxicity