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USMLE Step 1 Pharmacology

Subjects : health-sciences, usmle-step-1

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Answer 50 questions in 15 minutes.
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Match each statement with the correct term.
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1. Name two bile acid resins.
Reversible block of histamine H2 receptors
Albuterol - tertbutaline
cholestyramine - colestipol
1. Tolbutamide 2. Chlorpropamide 3. Glyburide 4. Glipizide

2. What is the mechanism of Tacrolimus (FK506)?
Hexamethonium is a nicotinic antagonist - and thus is a ganglionic blocker.
Well tolerated in general but occasionally - Nephrotoxicity - Ototoxicity - Thrombophlebitis - diffuse flushing='Red Man Syndrome'
Similar to cyclosporine; binds to FK- binding protein - inhibiting secretion of IL-2 and other cytokines.
Yes

3. Common toxicities associated with Griseofulvin?
fetal renal toxicity - hyperkalemia
increase AP duration - increase ERP - increase QT interval - for use When other arrhythmics fail
Teratogenic - Carcinogenic - Confusion - Headaches
decrease myocardial O2 consumption by: 1- decreasing end diastolic volume 2- decreasing BP 3- decreasing HR 4- decreasing contractility 5- decreasing ejection time

4. What are the Anti - TB drugs?
Rifampin - Ethambutol - Streptomycin - Pyrazinamide - Isoniazid (INH)
not a sulfonamide - but action is the same as furosemide
anticholinesterase glaucoma
Wide spectrum of systemic mycoses: Cryptococcus - Blastomyces - Coccidioides - Aspergillus - Histoplasma - Candida - Mucor

5. Antimicrobial prophylaxis for PCP
atropine - homatropine - tropicamide
Inhibits formation of Initiation Complex - causes misreading of mRNA - Bactericidal
Short.
TMP- SMZ (DOC) - aerosolized pentamidine

6. Sotalol - toxicity?
Aminoglycosides
Systemic mycoses
Penicillin - Cephalosporins - Vancomycin - Aminoglycosides - Fluoroquinolones - Metronidazole
torsade de pointes - excessive Beta block

7. Which individuals are predisposed to Sulfonamide - induced hemolysis?
1. Streptokinase 2. Urokinase 3. tPA (alteplase) - APSAC (anistreplase)
DHPG (dihydroxy-2- propoxymethyl guanine)
Acetylates and irreversibly inhibits cyclooxygenase (COX I and COX II) to prevent the conversion of arachidonic acid to prostaglandins.
G6PD deficient individuals

8. Name four Antiarrhythmic drugs in class IA.
Chronic gout.
Quinidine - Amiodarone - Procainamide - Disopyramide
Beta - lactamase cleavage of Beta - lactam ring
1) Serious Gram - infections resistant to other Beta lactams 2) Meningitis (most penetrate the BBB)

9. Dobutamine used for the tx of shock acts on Which receptors
Beta1 more than B2
Chronic gout.
- MT polymerization inhibitor(M phase) - MOPP - lymphoma - Willm's & choriocarcinoma - neurotoxicity and myelosuppression
Phosphorylation by a Viral Kinase

10. What is the mechanism of action of Allopurinol used to treat chronic gout?
Inhibits xanthine oxidase - decresing conversion of xanthine to uric acid.
It must be Phosphorylated by Viral Thymidine Kinase
- Alkalates DNA - CML - Pulmonary fibrosis hyperpigmentation
Short.

11. What is the only depolarizing neuromuscular blocking agent?
As PABA antimetabolites that inhibit Dihydropteroate Synthase - Bacteriostatic
Succinylcholine
1. Peptic ulcer 2. Gastritis 3. Esophageal reflux 4. Zollinger - Ellison syndrome
Stimulates beta adrenergic receptors

12. How is Amphotericin B used clinically?
Wide spectrum of systemic mycoses: Cryptococcus - Blastomyces - Coccidioides - Aspergillus - Histoplasma - Candida - Mucor
osmotic diuretic - increase tubular fluid osmolarity - thereby increasing urine flow
It acts presynaptically to increase NE release.
Pretreat with antihistamines and a slow infusion rate

13. Which diuretics cause alkalosis?
1. Peptic ulcer 2. Gastritis 3. Esophageal reflux 4. Zollinger - Ellison syndrome
loop diuretics - thiazides
Beta lactams - inhibit cell wall synthesis - Bactericidal
1. Meningococcal carrier state 2. Chemoprophylaxis in contacts of children with H. influenzae type B

14. What is the mechanism of action of Ticlopidine - Clopidogrel
Inhibits platelet aggregation by irreversibly inhibiting the ADP pathway involved in the binding of fibrinogen.
Pyridoxine (B6) administration
Ototoxicity - Hypokalemia - Dehydration - Allergy (sulfa) - Nephritis (interstitial) - Gout
Digitoxin>95% Digoxin 75%

15. Which drug(s) cause this reaction: Cutaneous flushing (4)?
Captopril - Enalapril - Lisinopril
1. Weight gain 2. Hepatotoxicity (troglitazone)
- Niacin - Ca++ channel blockers - adenosine - vancomycin
Inhibits cell wall mucopeptide formation - Bactericidal

16. Furosemide - clinical use?
1. Streptokinase 2. Urokinase 3. tPA (alteplase) - APSAC (anistreplase)
Imipenem
Inhibits cell wall synthesis ( binds to PBP3). A monobactam
edematous states (CHF - cirrhosis - nephrotic syndrome - pulm edema) - HTN - hypercalcemia

17. When is Rifampin not used in combination with other drugs?
Beta 2 agonist; desired effect is the relaxation of bronchial smooth muscle (Beta 2). Use during acute exacerbation.
1. Better bioavailability 2. 2 to 4 times longer half life 3. Can be administered subcutaneously 4. Does not require laboratory monitoring
1. Meningococcal carrier state 2. Chemoprophylaxis in contacts of children with H. influenzae type B
Scopolamine

18. What is the category - mechanism of action - and effect of Ipratroprium in Asthma treatment?
Glycoproteins from leukocytes that block various stages of viral RNA and DNA synthesis
Antileukotriene; blocks leukotriene receptors.
Can affect absorption - bioavailability - or urinary excretion of other drugs by altering gastric and urinary pH or by delaying gastric emptying.
Muscarinic antagonist; competatively blocks muscarinic receptors - preventing bronchoconstriction.

19. MOA: Disrupt fungal cell membranes
They activate the ciliary muscle of the eye (open angle) and pupillary sphincter (narrow angle).
Amphotericin B - Nystatin - Fluconazole/azoles
Ipratropium
Activates antithrombin III

20. Decrease Digoxin dose in renal failure?
YES
- Deferoxamine
1. Mycobacterium tuberculosis 2. Delays resistance to Dapsone When used of Leprosy 3. Used in combination with other drugs
is resistant

21. What is the category - method of use - and adverse effects of Salmeterol in Asthma treatment?
severe hypertension - CHF
Beta 2 agonist; used as a long - acting agent for prophylaxis. Adverse effects are tremor and arrhythmia.
Nephrotoxicity (esp. with Cephalosporins) - Ototoxicity (esp. with Loop Diuretics)
- Corticosteroids - heparin

22. What type of gout is treated with Probenacid?
Hypersensitivity reactions
DHPG (dihydroxy-2- propoxymethyl guanine)
Chronic gout.
Sildenafil fills the penis

23. How is Acyclovir used clinically?
impotence - asthma - CV effects (bradycardia - CHF - AV block) - CNS effects (sedation - sleep alterations)
Penicillin - Cephalosporins - Vancomycin - Aminoglycosides - Fluoroquinolones - Metronidazole
Treatment of hypertension - especially with renal disease (lowers bp centrally - so flow is maintained to kidney).
HSV - VZV - EBV - Mucocutaneous and Genital Herpes Lesions - Prophylaxis in Immunocompromised pts

24. In coma situations you rule out What (7)?

25. Ca2+ channel blockers - clinical use?
Beta 2 agonist; used as a long - acting agent for prophylaxis. Adverse effects are tremor and arrhythmia.
hypokalemia - slight hyperlipidemia - hyperuricemia - lassitude - hypercalcemia - hyperglycemia
Bleeding.
hypertension - angina - arrhythmias

26. Antimicrobial prophylaxis for Gonorrhea
- N- acetylcystine
Slow - limited by half lives of clotting factors
Ceftriaxone
Increased systolic and pulse pressure - decreased diastolic pressure - and little change in mean pressure.

27. Your patient wants an effective drug to treat his motion sickness - What would you prescribe
Scopolamine
Abortifacient.
Theoretically it could be used to block the cephalic phase of acid secretion (vagal stimulation).
1. Addison's disease 2. Inflammation 3. Immune suppression 4. Asthma

28. When is HIV therapy initiated?
No - it inhibits the release of Nor Epi
When pts have Low CD4+ (< 500 cells/cubic mm) or a High Viral Load
blocking the beta adrenergic receptor leads to decreased cAMP - and decreased Ca2+ flux
is resistant

29. What is the category of drug names ending in - ane (e.g. Halothane)
Directly of indirectly aid conversion of plasminogen to plasmin Which cleaves thrombin and fibrin clots. (It is claimed that tPA specifically converts fibrin - bound plasminogen to plasmin.)
Inhalational general anesthetic.
The COX-2 inhibitors should not have the corrosive effects of other NSAIDs on the gastrointestinal lining.
constipation - flushing - edema - CV effects (CHF - AV block - sinus node depression) - and torsade de pointes (Bepridil)

30. What is the memory key for the effect of aluminum hydroxide overuse?
The PTT.
NE increases bp - Which stimulates baroreceptors in the carotid sinus and the aorta. The CNS signals through vagal stimulation to decrease heart rate.
Vibrio cholerae Acne Chlamydia Ureaplasma Urealyticum Mycoplasma pneumoniae Borrelia burgdorferi (Lyme's) Rickettsia Tularemia
AluMINIMUM amount of feces.

31. What are common side effects of Protease Inhibitors?
- Alkalinize urine & dialysis
GI intolerance (nausea - diarrhea) - Hyperglycemia - Lipid abnormalities - Thrombocytopenia (Indinavir)
Hydralazine and Minoxidil
- Flumazenil

32. Which cancer drugs work at the level of proteins(2)?
- Cloazapine - carbamazapine - colchicine - PTU
- Vinca alkaloids(inhibit MT) - Paclitaxel
With an amino acid change of D- ala D- ala to D- ala D- lac
is resistant

33. Hydralazine - class and mechanism?
Neurotoxicity - Acute renal tubular necrosis
dry mouth - sedation - severe rebound hypertension
vasodilator - increases cGMP to induce smooth muscle relaxation (arterioles>veins; afterload reduction)
local anesthetic. CNS stimulation or depression. CV depression.

34. Name the common Nucleoside Reverse Transcriptase Inhibitors
Depolymerizes microtubules - impairing leukocyte chemotaxis and degranulation.
Foscarnet = pyroFosphate analog
Zidovudine (AZT) - Didanosine (ddI) - Zalcitabine (ddC) - Stavudine (d4T) - Lamivudine (3TC)
Md= (CpxCL)/F Cp= plas. Conc. CL=clear. F=bioaval.

35. What is a common side effect of Misoprostol?
severe orthostatic hypotension - blurred vision - constipation - sexual dysfunction
severe hypertension - CHF
Diarrhea
Used in combination therapy with SMZ to sequentially block folate synthesis

36. What class of drug is echothiophate? What is its indication?
anticholinesterase glaucoma
AluMINIMUM amount of feces.
No. Atropine is used to reduce urgency in mild cystitis. So it would aggravate the urinary retention.
Severe Gram - rod infections.

37. Which drug(s) cause this reaction: Stevens - Johnson syn. (3)?
1. Bleeding 2. Teratogenicity 3. Drug - drug interactions
- Ethosuxamide - sulfonamides - lamotrigine
Interferes with microtubule function - disrupts mitosis - inhibits growth
Nitrates

38. What conditions are treated with Metronidazole?
Giardiasis - Amoebic dysentery (E. histolytica) - Bacterial vaginitis (Gardnerella vaginalis) - Trichomonas
Used in combination therapy with SMZ to sequentially block folate synthesis
Hypersensitivity reactions
1) Hypersensitivity reactions 2) Increased nephrotoxicity of Aminoglycosides 3) Disulfiram - like reaction with ethanol (those with a methylthiotetrazole group - e.g. - cefamandole)

39. Which cancer drugs effect nuclear DNA (4)?
- Glucagon
- Alkalating agents+cisplatin - Doxorubicin+Dactinomycin - Bleomycin - Etoposide
Blastomyces - Coccidioides - Histoplasma - C. albicans; Hypercortisolism
Terminal D- ala of cell wall replaced with D- lac; Decreased affinity

40. What is the MOA for Metronidazole?
not a sulfonamide - but action is the same as furosemide
Cyclooxygenases (COX I - COX II).
Amphotericin B - Nystatin - Fluconazole/azoles
Forms toxic metabolites in the bacterial cell - Bactericidal

41. MOA: Block cell wall synthesis by inhib. Peptidoglycan cross - linking (7)
Used in combination therapy with SMZ to sequentially block folate synthesis
Penicillin - Ampicillin - Ticarcillin - Pipercillin - Imipenem - Aztreonam - Cephalosporins
TMP- SMZ
Phase 1 = prolonged depolarization - no antidote - effect potentiated by anticholinesterase; Phase 2 = repolarized but blocked - an anticholinesterase is the antidote for this phase.

42. What are the products and their toxicities of the metabolism of Methanol by / alcohol dehydrogenase?
Rare.
reduce levels of Angiotensin II - thereby preventing the inactivation of bradykinin (a potent vasodilator); renin level is increased
- ACE inhibitors (Losartan>no cough)
- Formaldehyde & formic acid - severe acidosis & retinal damage

43. What antimuscarinic agent is used in asthma and COPD?
Malaria (P. falciparum)
Protease inhibitor.
Ipratropium
decrease

44. What are four Sulfonylureas?
hyperaldosteronism - K+ depletion - CHF
1. Tolbutamide 2. Chlorpropamide 3. Glyburide 4. Glipizide
- Nitrate - hydroxocobalamin thiosulfate
Systemic mycoses

45. What is the effect of norepinephrine on bp and pulse pressure?
The PT.
Fast vs. Slow Acetylators
Increases mean - systolic - and diastolic bp - while there is little change in pulse pressure.
- N- acetylcystine

46. Antiarrhythmic class IC- toxicity?
Imipenem
proarrhythmic
- Class III antiarrhythmics (sotalol) - class IA (quinidine)
Scopolamine

47. Toxic side effects of the Azoles?
ACE inhibitor.
- Protamine
Hormone synthesis inhibition (Gynecomastia) - Liver dysfunction (Inhibits CYP450) - Fever - Chills
Prefers beta's at low doses - but at higher doses alpha agonist effects are predominantly seen.

48. How do the Protease Inhibitors work?
Inhibt Assembly of new virus by Blocking Protease Enzyme
severe hypertension - CHF
Neomycin
1. Antipyretic 2. Analgesic 3. Anti - inflammatory 4. Antiplatelet drug.

49. For Warfarin What is the Site of action
- Normalize K+ - Lidocaine - & Anti - dig Mab
Pretreat with antihistamines and a slow infusion rate
Neutropenia (ticlopidine); reserved for those who cannot tolerate aspirin.
Liver

50. What is the MOA of Polymyxins?
Bind cell membrane - disrupt osmotic properties - Are Cationc - Basic and act as detergents
- Glucagon
Anaerobic infections (e.g. - B. fragilis - C. perfringens)
- Airway - Breathing - Circulation - Dextrose (thiamine & narcan) - ABCD