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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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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. Which drug(s) cause this reaction: Disulfram - like reaction (4) ?
- Metronidazole - certain cephalosporins - procarbazine - sulfonylureas
Same as penicillin. Extended spectrum antibiotics
thick ascending limb
Na/K ATPase

2. Name two bile acid resins.
cholestyramine - colestipol
Leukotrienes increasing bronchial tone.
Cell membrane Ca2+ channels of cardiac sarcomere
Quinolones

3. What is the MOA for the Macrolides?
Altered bacterial Dihydropteroate Synthetase - Decreased uptake - or Increased PABA synthesis
Cryptococcal meningitis in AIDS patients and Candidal infections of all types
Blocks translocation - binds to the 23S rRNA of the 50S subunit - Bacteriostatic
- Aminocaproic acid

4. What are signs of Sildenafil (Viagra) toxicity?
Gram + cocci - Gram - rods - and Anerobes
Headache - flushing - dyspepsia - blue - green color vision.
NO HYPERURICEMIA - NO SULFA AllERGY; same as furosemide otherwise
H2 antagonist

5. What are three unwanted effects of Mifepristone?
1. Heavy bleeding 2. GI effects (n/v - anorexia) 3. Abdominal pain
Tricyclic antidepressant.
scopolamine
Clavulanic acid

6. How would you treat African Trypanosomiasis (sleeping sickness)?
1. Antipyretic 2. Analgesic 3. Anti - inflammatory 4. Antiplatelet drug.
Mg = Must go to the bathroom.
Antileukotriene; blocks synthesis by lipoxygenase.
Suramin

7. Hydralazine - clinical use?
The only local anesthetic with vasoconstrictive properties.
severe hypertension - CHF
Beta lactams - inhibit cell wall synthesis - Bactericidal
- Alkalating agent - testicular - bladder - ovary -& lung - Nephrotoxicity & CN VIII damage.

8. What is the category of drug names ending in - azepam (e.g. Diazepam)
- Fluoroquinolones
1. Pioglitazone 2. Rosiglitazone.
Norepinephrine
Benzodiazepine.

9. What is the lab value used to monitor the effectiveness of Warfarin therapy?
1. Suppresses organ rejection after transplantation 2. Selected autoimmune disorders.
hypertension - CHF - diabetic renal disease
Zidovudine (AZT) - Didanosine (ddI) - Zalcitabine (ddC) - Stavudine (d4T) - Lamivudine (3TC)
The PT.

10. Cocaine shares is mechanism of action with What antidepressant
- Ammonium Chloride
Nucleosides
TCA
TMP- SMZ

11. Antiarrhythmic class IV- primary site of action?
Pseudomonas species and Gram - rods
Inhibits cell wall mucopeptide formation - Bactericidal
AV nodal cells
Dopamine; causes its release from intact nerve terminals

12. Guanethidine enhances the release of Norepi?
NE acts presynaptically on alpha -2 receptors to inhibit its own release. ACh also acts presynaptically through M1 receptors to inhibit NE release.
No - it inhibits the release of Nor Epi
Activates antithrombin III
1. Hot flashes 2. Ovarian enlargement 3. Multiple simultaneous pregnancies 4. Visual disturbances

13. What is a possible result of overdose of Acetaminophen?
penicillinase resistant
Nifedipine - Verapamil - Diltiazem
Overdose produces hepatic necrosis; acetaminophen metablolite depletes glutathione and forms toxic tissue adducts in liver.
Sulfamethoxazole (SMZ) - Sulfisoxazole - Triple sulfas - Sulfadiazine

14. What is the category of drug names ending in - phylline (e.g. Theophylline)
Dopamine
local anesthetic. CNS stimulation or depression. CV depression.
Methylxanthine.
GI upset - Superinfections - Skin rashes - Headache - Dizziness

15. What are two toxicities of the Glitazones?
Beta -2 agonist.
1. Weight gain 2. Hepatotoxicity (troglitazone)
very short acting
Abortifacient.

16. How is Rifampin used clinically?
- Lithium
Binds to the Pyrophosphate Binding Site of the enzyme
1. Mycobacterium tuberculosis 2. Delays resistance to Dapsone When used of Leprosy 3. Used in combination with other drugs
It affects beta receptors equally and is used in AV heart block (rare).

17. Beta Blockers - CV toxicity?
hyperkalemia - endocrine effects (gynecomastia - anti - androgen)
Neutropenia
bradycardia - AV block - CHF
Zidovudine (AZT) - Didanosine (ddI) - Zalcitabine (ddC) - Stavudine (d4T) - Lamivudine (3TC)

18. What are the products and their toxicities of the metabolism of Ethylene Glycol by / alcohol dehydrogenase?
- Oxalic acid - Acidosis & nephrotoxicity
Ciprofloxacin - Norfloxacin - Ofloxacin - Grepafloxacin - Enoxacin - Nalidixic acid
Mycobacterium tuberculosis - the only agent used as solo prophylaxis against TB
Stimulating beta receptors stimulates heart rate - but beta receptor induced vasodilation reduces peripheral resistance.

19. What are two types of drugs that interfere with the action of Sucralfate and why?
Sucralfate cannot work in the presence of antacids or H2 blockers because it requires an acidic environment to polymerize.
Oral treatment of superficial infections
They activate the ciliary muscle of the eye (open angle) and pupillary sphincter (narrow angle).
Gentamicin - Neomycin - Amikacin - Tobramycin - Streptomycin

20. Adverse effects of ganglionic blockers?
Antibiotic - protein synthesis inhibitor.
They inhibit reuptake of NE at the nerve terminal (as does cocaine).
Topical and Oral - for Oral Candidiasis (Thrush)
severe orthostatic hypotension - blurred vision - constipation - sexual dysfunction

21. Which drug(s) cause this reaction: Hot flashes?
atropine - homatropine - tropicamide
TMP- SMZ
- Tamoxifen
Prophylaxis for Influenza A - Rubella; Parkinson's disease

22. What are the clinical indications for neostigmine?
Post - op and neurogenic ileus and urinary retention - myasthenia gravis - and reversal of neuromuscular junction blockade (post - op) through anticholinesterase activity.
Blastomyces - Coccidioides - Histoplasma - C. albicans; Hypercortisolism
hypertension - angina - arrhythmias
1)Binds penicillin - binding proteins 2) Blocks transpeptidase cross - linking of cell wall 3) Activates autolytic enzymes

23. List the specific antidote for this toxin: Tricyclic antidepressants
- NaHCO3
Leukopenia - Neutropenia - Thrombocytopenia - Renal toxicity
1. Bleeding 2. Thrombocytopenia 3. Drug - drug interactions
Liver

24. What are four conditions in Which H2 Blockers are used clinically?
1. Peptic ulcer 2. Gastritis 3. Esophageal reflux 4. Zollinger - Ellison syndrome
- Tetracycline - amiodarone - sulfonamides
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.
Anaerobes

25. For Heparin What is the Site of action
- MT polymerization stabilizer - Ovarian & breast CA - Myelosupperession & hypersensitivity.
Blood
osmotic diuretic - increase tubular fluid osmolarity - thereby increasing urine flow
- Hydralazine - Procainamide - INH - phenytoin

26. What is the mechanism of action and clinical use of the antiandrogen Flutamide?
Constant FRACTION eliminated per unit time.(exponential)
Flutamide is a nonsteroidal competitive inhibitor of androgens at the testosterone receptor - used in prostate carcinoma.
Acetylcholine esterase
Pentavalent Antimony

27. List the specific antidote for this toxin: Methanol & Ethylene glycol
Disulfiram - like reaction with EtOH - Headache
NE increases bp - Which stimulates baroreceptors in the carotid sinus and the aorta. The CNS signals through vagal stimulation to decrease heart rate.
- Ethanol - dialysis - & fomepizole
- ED 50 is less than the Km (less than 50% of receptors)

28. Would blockade of muscarininc receptors in the bladder be useful in treating urinary retention?
Mebendazole/Thiabendazole - Pyrantel Pamoate
Ld= (CpxVd)/F Cp=plasma conc. F= Bioaval.
No. Atropine is used to reduce urgency in mild cystitis. So it would aggravate the urinary retention.
- Disulfram & also sulfonylureas - metronidazole

29. Name three Antiarrhythmic drugs in class IC.
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.
- Sulfonamides - furosemide - methicillin - rifampin - NSAIDS (ex. ASA)
Flecainide - Encainide - Propafenone
Due to the presence of a bulkier R group

30. List the specific antidote for this toxin: Amphetamine
Sucralfate cannot work in the presence of antacids or H2 blockers because it requires an acidic environment to polymerize.
Indirect agonist - uptake inhibitor
- Ammonium Chloride
Chronic Hepatitis A and B - Kaposi's Sarcoma

31. Does Heparin have a long - medium - or short half life?
- Glucocorticoid withdrawal
Short.
Increases coumadin metabolism
Overdose produces hepatic necrosis; acetaminophen metablolite depletes glutathione and forms toxic tissue adducts in liver.

32. What is the category of drug names ending in - triptyline (e.g. Amitriptyline)
Tricyclic antidepressant.
NE increases bp - Which stimulates baroreceptors in the carotid sinus and the aorta. The CNS signals through vagal stimulation to decrease heart rate.
Primaquine
bradycardia - AV block - CHF

33. What is the formula for Volume of distribution (Vd)
Vd= (Amt. of drug in body/ Plasma drug conc.)
- Barbiturates - phenytoin - carbamazipine - rifampin - griseofulvin - quinidine
sedation - sleep alterations
decrease AP duration - affects ischemic or depolarized Purkinje and ventricular system

34. List the mechanism - clinical use - & toxicity of Methotrexate.
CMV Retinitis in IC pts When Ganciclovir fails
Lidocaine - Mexiletine - Tocainide
- S- phase anti - metabolite folate analogue - Luk - Lymp - sarc - RA - & psoriasis / - Reversible myelosuppression
- Tetracycline - amiodarone - sulfonamides

35. What is the category of drug names ending in - ipramine (e.g. Imipramine)
Primaquine
Digoxin=urinary Digitoxin=biliary
Inhalational general anesthetic.
Tricyclic antidepressant.

36. How is Foscarnet used clinically?
Chloramphenicol - Erythromycin/macrolides - Lincomycin - Clindamycin - Streptogramins (quinupristin - dalfopristin)
Inhibits organification and coupling of thyroid hormone synthesis. Also decreases peripheral conversion of T4 to T3.
1. Hypoglycemia (more common with 2nd - generation drugs: glyburide - glipizide) 2. Disulfiram - like effects (not seen with 2nd - generation drugs).
CMV Retinitis in IC pts When Ganciclovir fails

37. Which drug(s) cause this reaction: Anaphylaxis?
- Penicillin
Spironolactone - Triamterene - Amiloride (the K+ STAys)
Blocks translocation - binds to the 23S rRNA of the 50S subunit - Bacteriostatic
Prevents the release of calcium from the sarcoplasmic reticulum of skeletal muscle.

38. What is the mechanism of action of Warfarin (Coumadin)?
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.
Disulfiram - like reaction with EtOH - Headache
- Halothane - Valproic acid - acetaminophen - Amantia phalloides
Diarrhea - Urination - Miosis - Bronchospasm - Bradycardia - Excitation of skeletal muscle and CNS - Lacrimation - Sweating - and Salivation = DUMBBELS; also abdominal cramping

39. What are four clinical activities of Aspirin?
1. Antipyretic 2. Analgesic 3. Anti - inflammatory 4. Antiplatelet drug.
Modification via Acetylation
Penicillin - V
Pralidoxime regenerates active cholinesterase.

40. What is the MOA of Amantadine?
Blocks viral penetration/uncoating; may act to buffer the pH of the endosome
Slow - limited by half lives of clotting factors
TMP- SMZ (DOC) - aerosolized pentamidine
Antimetabolite derivative of 6- mercaptopurine that interferes with the metablolism and synthesis of nucleic acid.

41. For Heparin What is the Route of administration
Clavulanic acid
Paranteral (IV - SC)
hyperchloremic metabolic acidosis - neuropathy - NH3 toxicity - sulfa allergy
- Lithium

42. What is the category of drug names ending in - oxin (e.g. Digoxin)
hyperaldosteronism - K+ depletion - CHF
Cardiac glycoside (inotropic agent).
- Nitrate - hydroxocobalamin thiosulfate
Long.

43. What are two Alpha - glucosidase inhibitors?
Neostigmine - pyridostigmine edrophonium - physostigmine echothiophate
1. Acarbose 2. Miglitol
Hemolysis (if G6PD deficient) - Neurotoxicity - Hepatotoxicity - SLE- like syndrome
GI distress - Tooth discoloration and Inhibition of bone growth in children - Fanconi's syndrome - Photosensitivity

44. What are the side effects of Polymyxins?
Neurotoxicity - Acute renal tubular necrosis
Ld= (CpxVd)/F Cp=plasma conc. F= Bioaval.
Inhibits reabsorption of uric acid.
- DNA intercalator - Hodgkin's - myeloma - sarcoma - and solid tumors - Cardiotoxicity & alopecia

45. What are the products and their toxicities of the metabolism of ethanol by / alcohol dehydrogenase?
- Acetaldehyde - Nausea - vomiting - headache - & hypotension
proximal convoluted tubule
Bethanechol - Neostigmine - physostigmine
Prevents release of mediators from mast cells. Effective only for the prophylaxis of asthma. Not effective during an acute attack.

46. 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
- Vitamin K & fresh frozen plasma
Inhibits DNA dependent RNA polymerase
- Steroids - Tamoxifen

47. Beta Blockers - CNS toxicity?
sedation - sleep alterations
viral kinase
Praziquantel
hyperchloremic metabolic acidosis - neuropathy - NH3 toxicity - sulfa allergy

48. Adverse effect of Nitroprusside?
K+ wasting - metabolic alkalosis - hypotension - ototoxicity
Neomycin
Recurrent UTIs - Shigella - Salmonella - Pneumocystis carinii pneumonia
cyanide toxicity (releases CN)

49. Adverse effects of Loop Diuretics?
Bactericidal for: Gram + rod and cocci - Gram - cocci - and Spirochetes
Nucleosides
aPTT (intrinsic pathway)
K+ wasting - metabolic alkalosis - hypotension - ototoxicity

50. How does resistance to Vancomycin occur?
- partial agonist can have increased - decreased - /A21or equal potency as full agonist. - Potency is an independent factor.
Triple Therapy' 2 Nucleoside RT Inhibitors with a Protease Inhibitor
Penicillin.
With an amino acid change of D- ala D- ala to D- ala D- lac