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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. Acetazolamide causes?

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2. What are three complications of Warfarin usage?
Bacitracin - Vancomycin
1. Bleeding 2. Teratogenicity 3. Drug - drug interactions
- NaHCO3
- Deferoxamine

3. What is the lab value used to monitor the effectiveness of Heparin therapy?
- Ethanol - dialysis - & fomepizole
The PTT.
Leukotrienes increasing bronchial tone.
propanolol - esmolol - metoprolol - atenolol - timolol

4. Name the common Aminoglycosides (5)
atropine - homatropine - tropicamide
They inhibit reuptake of NE at the nerve terminal (as does cocaine).
Gentamicin - Neomycin - Amikacin - Tobramycin - Streptomycin
The PTT.

5. 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.
Interferes with microtubule function - disrupts mitosis - inhibits growth
Chloramphenicol - Erythromycin/macrolides - Lincomycin - Clindamycin - Streptogramins (quinupristin - dalfopristin)
Nifedipine - Verapamil - Diltiazem

6. What is the category of drug names ending in - cycline (e.g. Tetracycline)
Onchocerciasis ('river blindness'-- rIVER- mectin)
Indomethacin is used to close a patent ductus arteriosus.
- Protamine
Antibiotic - protein synthesis inhibitor.

7. Beta Blockers - site of action?
Prevention of NSAID- induced peptic ulcers - maintains a PDA.
narcolepsy - obesity - and attention deficit disorder (I wouldn't recommend this)
Beta adrenergic receptors and Ca2+ channels (stimulatory)
Extended spectrum penicillin: certain Gram + bacteria and Gram - rods

8. What is a common side effect of Colchicine used to treat acute gout - especially When given orally?
Indomethacin is used to close a patent ductus arteriosus.
GI side effects. (Indomethacin is less toxic - more commonly used.)
dry mouth - sedation - severe rebound hypertension
BM suppression (neutropenia - anemia) - Peripheral neuropathy

9. Are penicillinase resistant
collecting ducts
- partial agonist can have increased - decreased - /A21or equal potency as full agonist. - Potency is an independent factor.
Corticosteroids; prevent production of leukotrienes from arachodonic acid by blocking phospholipase A2. Drugs of choice in a patient with status asthmaticus (in combination with albuterol.)
Methicillin - Nafcillin - and Dicloxacillin

10. Adverse effects of Methyldopa?

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11. What is the main clinical use for the thrombolytics?
Erythromycin - Azithromycin - Clarithromycin
hypertrichosis - pericardial effusion - reflex tachycardia - angina - salt retention
Early myocardial infarction.
Norepinephrine

12. What effect would atropine have on the preganglionic sympathetic activation of sweat glands? Would this person sweat?
toxic
None. No - because atropine would block the postganglionic muscarinic receptors involved in sweat gland stimulation.
TCA
1. Aluminum hydroxide: constipation and hypophosphatemia 2. Magnesium hydroxide: diarrhea 3. Calcium carbonate: Hypercalcemia - rebound acid increase - All may cause hypokalemia

13. Foscarnet does not require activation by a...
To inhibit renal Dihydropeptidase I and decrease Imipenem inactivation in the renal tubules
Blocks Peptide Bond formation at the 50S subunit - Bacteriostatic
YES
viral kinase

14. What is the category - mechanism of action - and particular use of beclomethasone and prednisone in Asthma treatment?
Corticosteroids; prevent production of leukotrienes from arachodonic acid by blocking phospholipase A2. Drugs of choice in a patient with status asthmaticus (in combination with albuterol.)
1. Antipyretic 2. Analgesic 3. Anti - inflammatory 4. Antiplatelet drug.
Neutropenia
Indirect agonist - uptake inhibitor

15. Name three ACE inhibitors?
sedation - depression - nasal stuffiness - diarrhea
Hypersensitivity reactions
Extended spectrum penicillin: certain Gram + bacteria and Gram - rods
Captopril - Enalapril - Lisinopril

16. How are Interferons (INF) used clinically?

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

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18. What cholinergic inhibitor acts by directly inhibiting Ach release at the presynaptic terminal
Botulinum
Does not cross
Inhibt Assembly of new virus by Blocking Protease Enzyme
- reduction - oxy - & hydrolysis - H2O sol. Polar product - P450

19. Dobutamine used for the tx of shock acts on Which receptors
Ca2+ (Loops Lose calcium)
Beta1 more than B2
Tricyclic antidepressant.
AluMINIMUM amount of feces.

20. Would blockade of muscarininc receptors in the bladder be useful in treating urinary retention?
Cyclooxygenases (COX I - COX II).
Succinylcholine
No. Atropine is used to reduce urgency in mild cystitis. So it would aggravate the urinary retention.
- Ethosuxamide - sulfonamides - lamotrigine

21. Which drug(s) cause this reaction: Extrapyramidal side effects (3)?
- Chlorpromazine - thioridazine - haloperidol
- Shifts the curve to the right - increases Km
1. Meningococcal carrier state 2. Chemoprophylaxis in contacts of children with H. influenzae type B
Same as penicillin. Act as narrow spectrum antibiotics

22. Which drug(s) cause this reaction: Cinchonism (2)?
hyperkalemia - endocrine effects (gynecomastia - anti - androgen)
Ld= (CpxVd)/F Cp=plasma conc. F= Bioaval.
Fluconazole - Ketoconazole - Clotrimazole - Miconazole - Itraconazole
- Quinidine - quinine

23. Antiarrhythmic class II- effects?
Cilastatin
decrease the slope of phase 4 - increase PR interval (the AV node is particularly sensitive)
AV nodal cells
penicillinase resistant

24. What is the formula for Clearance (CL)
Malaria (P. falciparum)
Neutropenia (ticlopidine); reserved for those who cannot tolerate aspirin.
Blocks translocation - binds to the 23S rRNA of the 50S subunit - Bacteriostatic
CL= (rate of elimination of drug/ Plasma drug conc.)

25. Which of epi - norepi - or isoproterenol results in bradycardia?
- Ammonium Chloride
- Sulfonamides - INH - ASA - Ibuprofen - primaquine - nitrofurantoin /- pyrimethamine - chloramphenicol
Norepinephrine
Carbenicillin - Piperacillin - and Ticarcillin

26. Steady state concentration is reached in __ number of half - lifes
Scopolamine
decrease conduction velocity - increase ERP - increase PR interval
Potent immunosuppressive used in organ transplant recipients.
In 4 half - lifes= (94%) T1/2 = (0.7x Vd)/CL

27. How do you treat coma in the ER (4)?
Centrally acting alpha agonist - thus causing a decrease in central adrenergic outflow - spairing renal blood flow
- Airway - Breathing - Circulation - Dextrose (thiamine & narcan) - ABCD
Used in combination therapy with SMZ to sequentially block folate synthesis
- Cimetidine - ketoconazole - spironolactone - digitalis - EtOH - estrogens

28. How is Griseofulvin used clinically?
Liver
Oral treatment of superficial infections
Inhibit DNA Gyrase (topoisomerase II) - Bactericidal
compensatory tachycardia - fluid retention - lupus - like syndrome

29. What parasites are treated with Pyrantel Pamoate (more specific)?
Tricyclic antidepressant.
fetal renal toxicity - hyperkalemia - Cough - Angioedema - Proteinuria - Taste changes - hypOtension - Pregnancy problems - Rash - Increased renin - Lower Angiotensin II (CAPTOPRIL)
- Physostigmine salicylate
Giant Roundworm (Ascaris) - Hookworm (Necator/Ancylostoma) - Pinworm (Enterobius)

30. K+ sparing diuretics - clinical use?
Oxygen
- Tricyclic antidepressants
-100% oxygen - hyperbaric
hyperaldosteronism - K+ depletion - CHF

31. What is the clinical use for Clomiphene?
Treatment of infertility.
- Ethosuxamide - sulfonamides - lamotrigine
Hormone synthesis inhibition (Gynecomastia) - Liver dysfunction (Inhibits CYP450) - Fever - Chills
Ganciclovir is more toxic to host enzymes

32. Nifedipine has similar action to?
Reversibly inhibits cyclooxygenase - mostly in CNS. Inactivated peripherally.
1. Heavy bleeding 2. GI effects (n/v - anorexia) 3. Abdominal pain
Pseudomembranous colitis (C. difficile) - fever - diarrhea
Nitrates

33. Resistance mechanisms for Aminoglycosides
Impairs the synthesis of vitamin K- dependent clotting factors
Sulfonamide Loop Diuretic. Inhibits ion co - transport system of thick ascending loop. Abolishes hypertonicity of the medulla - thereby preventing concentration of the urine.
- Topo II inhibitor(GII specific) - Oat cell of Lung & prostate - & testicular - Myelosuppression & GI irritation.
Modification via Acetylation - Adenylation - or Phosphorylation

34. List the specific antidote for this toxin: Iron
GI discomfort - Acute cholestatic hepatitis - Eosinophilia - Skin rashes
Chronic Hepatitis A and B - Kaposi's Sarcoma
Phase 1 = prolonged depolarization - no antidote - effect potentiated by anticholinesterase; Phase 2 = repolarized but blocked - an anticholinesterase is the antidote for this phase.
- Deferoxamine

35. What cholinomimetics might your pt be taking for his glaucoma
Carbachol - pilocarpine - physostigmine - echothiophate
1. Phospholipase A2 is prevented from releasing arachidonic acid 2. Decreases protein synthesis thus lowering amount of Cyclooxygenase enzymes
Aplastic anemia (dose independent) - Gray Baby Syndrome
Onchocerciasis ('river blindness'-- rIVER- mectin)

36. What is the possible mechanism and effect of Metformin in treating diabetes?
anuria - CHF
Mechanism unknown; possibly inhibits gluconeogenesis and increases glycolysis; effect is to decrease serum glucose levels
Foscarnet = pyroFosphate analog
1. Hypoglycemia (more common with 2nd - generation drugs: glyburide - glipizide) 2. Disulfiram - like effects (not seen with 2nd - generation drugs).

37. While at a tail gait party - you bite into a sandwich that a yellow jacket is also enjoying. Knowing your allergy to this creature - What should you do?
Epinephrine to treat anaphylaxis. Also useful if you have open angle glaucoma - asthma - or hypotension.
INH: Injures Neurons and Hepatocytes
- Alkalate DNA - Brain tumors - CNS toxicity
GI upset

38. MOA for Penicillin (3 answers)?
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.
1)Binds penicillin - binding proteins 2) Blocks transpeptidase cross - linking of cell wall 3) Activates autolytic enzymes
hyperkalemia - endocrine effects (gynecomastia - anti - androgen)
Babiturate.

39. What is a possible result of overdose of Acetaminophen?
Overdose produces hepatic necrosis; acetaminophen metablolite depletes glutathione and forms toxic tissue adducts in liver.
increased AP duration - increased ERP increased QT interval. Atrial and ventricular.
impotence - exacerbation of asthma - CV effects - CNS effects - may mask hypoclycemia
1. Antiandrogen 2. Nausea 3. Vomiting

40. What would be the effect on blood pressure with infusion of the alpha -2 agonist clonidine?
orthostatic and exercise hypotension - sexual dysfunction - diarrhea
Stimulates beta adrenergic receptors
Aminoglycosides
Initially vasoconstriction would increase bp - but then it acts on central alpha -2 receptors to decrease adrenergic outflow resulting in decreased bp.

41. List the specific antidote for this toxin: Arsenic (all heavy metals)
1. Acarbose 2. Miglitol
Sucralfate cannot work in the presence of antacids or H2 blockers because it requires an acidic environment to polymerize.
- Topo II inhibitor(GII specific) - Oat cell of Lung & prostate - & testicular - Myelosuppression & GI irritation.
- Dimercaprol - succimer

42. What is the clinical use for Warfarin?
very short acting
1. Meningococcal carrier state 2. Chemoprophylaxis in contacts of children with H. influenzae type B
Chronic anticoagulation.
Theoretically it could be used to block the cephalic phase of acid secretion (vagal stimulation).

43. What is combination TMP- SMZ used to treat?
Recurrent UTIs - Shigella - Salmonella - Pneumocystis carinii pneumonia
GI discomfort - Acute cholestatic hepatitis - Eosinophilia - Skin rashes
1. Bleeding 2. Thrombocytopenia 3. Drug - drug interactions
Inhibit intestinal bursh border Alpha - glucosidases; delayed hydrolysis of sugars and absorption of sugars leading to decresed postprandial hyperglycemia.

44. What is Metronidazole combined with for 'triple therapy'? Against What organism?
Bismuth and Amoxicillin or Tetracycline; against Helobacter pylori
Pregnant women - Children; because animal studies show Damage to Cartilage
Methylation of rRNA near Erythromycin's ribosome binding site
Polymyxins

45. List the specific antidote for this toxin: Antimuscarinic (anticholinergic)
Albuterol - tertbutaline
Pentamidine
- Physostigmine salicylate
- MT polymerization stabilizer - Ovarian & breast CA - Myelosupperession & hypersensitivity.

46. What is the mechanism of action and clinical use of the antiandrogen Flutamide?
TCA
Flutamide is a nonsteroidal competitive inhibitor of androgens at the testosterone receptor - used in prostate carcinoma.
Rash - Pseudomembranous colitis
Pretreat with antihistamines and a slow infusion rate

47. How does a noncompetitive antagonist effect an agonist?
- Shifts the curve down - reduces Vmax
Small lipid - soluble molecule
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
Sulfonamides - Trimethoprim

48. Is toxicity rare or common whith Cromolyn used in Asthma prevention?
1) Hypersensitivity reactions 2) Increased nephrotoxicity of Aminoglycosides 3) Disulfiram - like reaction with ethanol (those with a methylthiotetrazole group - e.g. - cefamandole)
Amphetamine and Ephedrine
- Methotrexate - 5 FU - 6 mercaptopurine
Rare.

49. Clonidine is the preferred sym pathomimetic tx of HTN in pts with renal disease - why??
Ipratropium
Same as penicillin. Extended spectrum antibiotics
Centrally acting alpha agonist - thus causing a decrease in central adrenergic outflow - spairing renal blood flow
thick ascending limb

50. Which drug(s) cause this reaction: Hot flashes?
Inhalational general anesthetic.
- Tamoxifen
1. Aluminum hydroxide: constipation and hypophosphatemia 2. Magnesium hydroxide: diarrhea 3. Calcium carbonate: Hypercalcemia - rebound acid increase - All may cause hypokalemia
impotence - exacerbation of asthma - CV effects - CNS effects - may mask hypoclycemia