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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.
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1. Which drug(s) cause this reaction: P450 induction(6)?
- Chloramphenicol - benzene - NSAIDS - PTU - phenytoin
- Barbiturates - phenytoin - carbamazipine - rifampin - griseofulvin - quinidine
Atropine pts are suffering from Cholinestrase inhibitor poisining (Nerve gas/Organophosphate poisining)
Methylation of rRNA near Erythromycin's ribosome binding site

2. Thiazides - site of action?
Rash - Pseudomembranous colitis
distal convoluted tubule (early)
sedation - depression - nasal stuffiness - diarrhea
- Vitamin K & fresh frozen plasma

3. Oral Penicillin
- Sulfonamides - furosemide - methicillin - rifampin - NSAIDS (ex. ASA)
Penicillin - V
- MT polymerization inhibitor(M phase) - MOPP - lymphoma - Willm's & choriocarcinoma - neurotoxicity and myelosuppression
- Alkalate DNA - Brain tumors - CNS toxicity

4. What is the MOA for Carbenicillin - Piperacillin - and Ticarcillin?
Inhibition of 50S peptidyl transferase - Bacteriostatic
collecting ducts
Same as penicillin. Extended spectrum antibiotics
Beta - lactamase cleavage of Beta - lactam ring

5. Name four HMG- CoA reductase inhibitors.
Beta antagonist.
Blastomyces - Coccidioides - Histoplasma - C. albicans; Hypercortisolism
Lovastatin - Pravastatin - Simvastatin - Atorvastatin
Suramin

6. A common side effects of Interferon (INF) treatment is?
- A57Blue lines in gingiva & long bones - Encephalopathy & Foot drop - Abdominal colic / - Sideroblastic anemia
Hypersensitivity reactions
Reversibly inhibit cyclooxygenase (COX I and COX II). Block prostaglandin synthesis.
Neutropenia

7. List the specific antidote for this toxin: Copper
- Penicillamine
edrophonium (extremely short acting anticholinesterase)
TMP- SMZ
Erythromycin - Azithromycin - Clarithromycin

8. Why would you give a drug like pancuronium or succinylcholine?
- Clindamycin
AZT
Useful in muscle paralysis during surgery or mechanical ventilation.
Lidocaine - Mexiletine - Tocainide

9. Which drug(s) cause this reaction: Tendonitis and rupture?
Finasteride inhibits 5 Alpha - reductase - this decreases the conversion of testosterone to dihydrotestosterone - useful in BPH
- Fluoroquinolones
In treatment of malignant hyperthermia - due to concomitant use of halothane and succinylcholine. Also in neuroleptic malignant syndrome - a toxicity of antipsychotic drugs.
Penicillin - Cephalosporins - Vancomycin - Aminoglycosides - Fluoroquinolones - Metronidazole

10. Does Ampicillin or Amoxicillin have a greater oral bioavailability?
Clomiphene is a partial agonist at estrogen receptors in the pituitary gland. Prevents normal feedback inhibition and increses release of LH and FSHfrom the pituitary - Which stimulates ovulation.
cross - allergenic
AmOxicillin has greater Oral bioavailability
1. Infertility (pulsatile) 2. Prostate cancer (continuous: use with flutamide) 3. Uterine fibroids

11. What is the most common cause of Pt noncompliance with Macrolides?
GI discomfort
Nucleosides
cardiac depression - peripheral edema - flushing - dizziness - constipation
- Isoniazid

12. List the specific antidote for this toxin: Arsenic (all heavy metals)
Binding to the presynaptic alpha 2 release modulating receptors
- Dimercaprol - succimer
Prevention of NSAID- induced peptic ulcers - maintains a PDA.
NO AP duration effect. useful in V- tach that progresses to V- fib and in intractable SVT Last RESORT

13. What is the loading dose formula?
Ld= (CpxVd)/F Cp=plasma conc. F= Bioaval.
cross - allergenic
Beta -2 agonist.
Amphetamine and Ephedrine

14. What are three complications of Warfarin usage?
1. Bleeding 2. Teratogenicity 3. Drug - drug interactions
Acts as a wide spectrum carbapenem
HTN - CHF - calcium stone formation - nephrogenic DI.
Flecainide - Encainide - Propafenone

15. What are common toxicities related to Vancomycin therapy?

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16. List the specific antidote for this toxin: Digitalis
- Normalize K+ - Lidocaine - & Anti - dig Mab
Muscarinic antagonist; competatively blocks muscarinic receptors - preventing bronchoconstriction.
competitive inhibirot of aldosterone in the cortical collecting tubule
YES

17. Ethacrynic Acid - clinical use?
Inhibits reabsorption of uric acid.
Only in limited amounts
Diuresis in pateints with sulfa allergy
Staphlococcus aureus and Clostridium difficile (pseudomembranous colitis)

18. List the mechanism - clinical use - & toxicity of Prednisone.

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19. Which individuals are predisposed to Sulfonamide - induced hemolysis?
TMP- SMZ (DOC) - aerosolized pentamidine
- Methylene blue
Lidocaine - Mexiletine - Tocainide
G6PD deficient individuals

20. Can Heparin be used during pregnancy?
Inhibit Ergosterol synthesis
Inhibits DNA dependent RNA polymerase
Nephrotoxicity (esp. with Cephalosporins) - Ototoxicity (esp. with Loop Diuretics)
Yes - it does not cross the placenta.

21. Name two LPL stimulators.
Terminal D- ala of cell wall replaced with D- lac; Decreased affinity
- Penicillin
Treatment of infertility.
Gemfibrozil - Clofibrate

22. Antiarrhythmic class IC- effects?
- B51Naloxone / naltrexone (Narcan)
Ganciclovir is more toxic to host enzymes
NO AP duration effect. useful in V- tach that progresses to V- fib and in intractable SVT Last RESORT
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

23. What cholinomimetics might your pt be taking for his glaucoma
Hypokalemic metabolic alkalosis - hyponatremia - hyperGlycemia - hyperLipidemia - hyperUricemia - hyperCalcemia - sulfa allergy.
Acute gout.
Carbachol - pilocarpine - physostigmine - echothiophate
Antifungal.

24. Name the common Azoles
- Phase I (clinical tests) - Phase II - Phase III - PhaseIV (surveillance)
Fluconazole - Ketoconazole - Clotrimazole - Miconazole - Itraconazole
increase AP duration - increase ERP - increase QT interval - for use When other arrhythmics fail
Neutropenia (ticlopidine); reserved for those who cannot tolerate aspirin.

25. For Warfarin What is the Structure
prevention of nodal arrhythmias (SVT)
Small lipid - soluble molecule
- Steroids - Tamoxifen
Beta Blockers

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

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27. What can result due to antacid overuse?
Prophylaxis for Influenza A - Rubella; Parkinson's disease
Inhibit RT of HIV and prevent the incorporation of viral genome into the host DNA
Can affect absorption - bioavailability - or urinary excretion of other drugs by altering gastric and urinary pH or by delaying gastric emptying.
Praziquantel

28. Spironolactone - mechanism?
competitive inhibirot of aldosterone in the cortical collecting tubule
- DNA intercalator - testicular & lymphomas - Pulmonary fibrosis mild myelosuppression.
Nucleosides
- aminoglycosides - loop diuretics - cisplatin

29. What are the four conditions in Which Omeprazole - Lansoprazole is used?
Chronic gout.
Inhibits cGMP phosphodiesterase - casuing increased cGMP - smooth muscle relaxation in the corpus cavernosum - increased blood flow - and penile erection.
hypertrichosis - pericardial effusion - reflex tachycardia - angina - salt retention
1. Peptic ulcer 2. Gastritis 3. Esophageal reflux 4. Zollinger - Ellison syndrome

30. What are three toxicities of Leuprolied?
fetal renal toxicity - hyperkalemia
Inhibit DNA Gyrase (topoisomerase II) - Bactericidal
Inhibit RT of HIV and prevent the incorporation of viral genome into the host DNA
1. Antiandrogen 2. Nausea 3. Vomiting

31. What is the category of drug names ending in - olol (e.g. Propranolol)
Beta antagonist.
Binding to the presynaptic alpha 2 release modulating receptors
These B-2 agonists cause respiratory smooth muscle to relax.
Benzodiazepine.

32. What is the memory key for Metronidazole's clinical uses?
GET on the Metro
ACE inhibitor.
cortical collecting tubule
Beta adrenergic receptors and Ca2+ channels (stimulatory)

33. Which antimuscarinic agents are used in producing mydriasis and cycloplegia?
Alpha -1 antagonist
atropine - homatropine - tropicamide
Blocks Norepi - but not Dopamine
is resistant

34. What is the mechanism of action of Heparin?
Ca2+ (Loops Lose calcium)
Heparin catalyzes the activation of antithrombin III.
Pralidoxime regenerates active cholinesterase.
Post - op and neurogenic ileus and urinary retention - myasthenia gravis - and reversal of neuromuscular junction blockade (post - op) through anticholinesterase activity.

35. What is the mechanism of action and clinical use of the antiandrogens Ketoconazole and Spironolactone?
Inhibit steroid synthesis - used in the treatment of polycystic ovarian syndrome to prevent hirsutism.
- Estrogen receptor antagonist - Breast CA - increased endometrial CA risk
Liver
severe orthostatic hypotension - blurred vision - constipation - sexual dysfunction

36. List the specific antidote for this toxin: Warfarin
Ciprofloxacin - Norfloxacin - Ofloxacin - Grepafloxacin - Enoxacin - Nalidixic acid
Used in combination therapy with SMZ to sequentially block folate synthesis
AmOxicillin has greater Oral bioavailability
- Vitamin K & fresh frozen plasma

37. How would you reverse the effect of a neuromuscular blocking agent?
1. Suppresses organ rejection after transplantation 2. Selected autoimmune disorders.
Hemolysis (if G6PD deficient) - Neurotoxicity - Hepatotoxicity - SLE- like syndrome
hypokalemia - slight hyperlipidemia - hyperuricemia - lassitude - hypercalcemia - hyperglycemia
Give an antichloinesterase - neostigmine - edrophonium - etc

38. Ca2+ channel blockers - site of action?
1. Acarbose 2. Miglitol
Cardiac glycoside (inotropic agent).
Cell membrane Ca2+ channels of cardiac sarcomere
Atropine would also block the receptors in the ciliary muscle - causing an impairment in accommodation (cycloplegia).

39. How does angiotensin II affect NE release?
fetal renal toxicity - hyperkalemia - Cough - Angioedema - Proteinuria - Taste changes - hypOtension - Pregnancy problems - Rash - Increased renin - Lower Angiotensin II (CAPTOPRIL)
It acts presynaptically to increase NE release.
Similar to cyclosporine; binds to FK- binding protein - inhibiting secretion of IL-2 and other cytokines.
1. Antiandrogen 2. Nausea 3. Vomiting

40. What are Amantadine - associated side effects?
Inhibits cell wall synthesis ( binds to PBP3). A monobactam
Ataxia - Dizziness - Slurred speech
Resistant Gram - infections
all of them

41. Hydrochlorothiazide - mechanism?
Similar to cyclosporine; binds to FK- binding protein - inhibiting secretion of IL-2 and other cytokines.
Megaloblastic anemia - Leukopenia - Granulocytopenia
Phosphorylation by a Viral Kinase
Inhibits NaCl reabsorption in the early distal tubule. Decreases Ca2+ excretion.

42. Ibutilide - toxicity?
NO AP duration effect. useful in V- tach that progresses to V- fib and in intractable SVT Last RESORT
Increases coumadin metabolism
torsade de pointes
ARF - shock - drug overdose - decrease intracranial/intraocular pressure

43. How do we stop angina?
Beta antagonist.
decrease myocardial O2 consumption by: 1- decreasing end diastolic volume 2- decreasing BP 3- decreasing HR 4- decreasing contractility 5- decreasing ejection time
Headache - flushing - dyspepsia - blue - green color vision.
Ataxia - Dizziness - Slurred speech

44. What drug is used during the pregnancy of an HIV+ mother? - Why?
- Triggers apoptosis - CLL - Hodgkin's in MOPP - Cushing - like syndrome
AZT - to reduce risk of Fetal Transmission
CL= (rate of elimination of drug/ Plasma drug conc.)
Oral treatment of superficial infections

45. Which drug(s) cause this reaction: G6PD hemolysis(8)?
torsade de pointes - excessive Beta block
cardiac muscle: Verapamil>Diltiazem>Nifedipine
sedation - sleep alterations
- Sulfonamides - INH - ASA - Ibuprofen - primaquine - nitrofurantoin /- pyrimethamine - chloramphenicol

46. What is the MOA for Trimethoprim (TMP)?
cortical collecting tubule
Inhibits bacterial Dihydrofolate Reductase - Bacteriostatic
decrease conduction velocity - increase ERP - increase PR interval
Chronic Hepatitis A and B - Kaposi's Sarcoma

47. What is the mecanism of action - effective period - and ineffective period of use for Cromolyn in treating Asthma?
Prevents release of mediators from mast cells. Effective only for the prophylaxis of asthma. Not effective during an acute attack.
TMP- SMZ (DOC) - aerosolized pentamidine
Ibuprofen - Naproxen - and Indomethacin
Acts as a wide spectrum carbapenem

48. Mg+- clinical use?
effective in torsade de pointes and digoxin toxicity
Inhibit steroid synthesis - used in the treatment of polycystic ovarian syndrome to prevent hirsutism.
1. Antiandrogen 2. Nausea 3. Vomiting
not a sulfonamide - but action is the same as furosemide

49. What should not be taken with Tetracyclines? / Why?
Rare.
1) Hypersensitivity reactions 2) Increased nephrotoxicity of Aminoglycosides 3) Disulfiram - like reaction with ethanol (those with a methylthiotetrazole group - e.g. - cefamandole)
Milk or Antacids - because divalent cations inhibit Tetracycline absorption in the gut
Acetylcholinesterase; ACh is broken down into choline and acetate.

50. Hydralazine - class and mechanism?
VACUUM your Bed Room'
Decreased uptake or Increased transport out of cell
vasodilator - increases cGMP to induce smooth muscle relaxation (arterioles>veins; afterload reduction)
-100% oxygen - hyperbaric