Test your basic knowledge |

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. What is the clinical use for Heparin?
Immediate anticoagulation for PE - stroke - angina - MI - DVT.
Slow - limited by half lives of clotting factors
NO
Prevents release of mediators from mast cells. Effective only for the prophylaxis of asthma. Not effective during an acute attack.

2. What are Amantadine - associated side effects?
Phase 1 = prolonged depolarization - no antidote - effect potentiated by anticholinesterase; Phase 2 = repolarized but blocked - an anticholinesterase is the antidote for this phase.
Ataxia - Dizziness - Slurred speech
Gram + cocci - Gram - rods - and Anerobes
- Alkalinize urine & dialysis

3. What are the products and their toxicities of the metabolism of ethanol by / alcohol dehydrogenase?
blocking the beta adrenergic receptor leads to decreased cAMP - and decreased Ca2+ flux
No - hemicholinum block the uptake of Choline and thus Ach synthesis
NO
- Acetaldehyde - Nausea - vomiting - headache - & hypotension

4. Are penicillinase resistant
When pts have Low CD4+ (< 500 cells/cubic mm) or a High Viral Load
Methicillin - Nafcillin - and Dicloxacillin
Beta Blockers
- Ethanol - dialysis - & fomepizole

5. Dobutamine used for the tx of shock acts on Which receptors
Beta1 more than B2
distal convoluted tubule (early)
Same as penicillin. Extended spectrum antibiotics
Aplastic anemia (dose independent) - Gray Baby Syndrome

6. What is an acronym to remember Anti - TB drugs?
loop diuretics - thiazides
PT
RESPIre
Carbenicillin - Piperacillin - and Ticarcillin

7. Name four Antiarrhythmic drugs in class IA.
Intrathecally
Flecainide - Encainide - Propafenone
Initially vasoconstriction would increase bp - but then it acts on central alpha -2 receptors to decrease adrenergic outflow resulting in decreased bp.
Quinidine - Amiodarone - Procainamide - Disopyramide

8. What is the mechanism of action of Omeprazole - Lansoprazole?
Irreversibly inhibits H+/K+ ATPase in stomach parietal cells.
Heparin catalyzes the activation of antithrombin III.
Overdose produces hepatic necrosis; acetaminophen metablolite depletes glutathione and forms toxic tissue adducts in liver.
It must be Phosphorylated by Viral Thymidine Kinase

9. Adverse effects of Reserpine?
Antileukotriene; blocks leukotriene receptors.
- Tamoxifen
AmOxicillin has greater Oral bioavailability
sedation - depression - nasal stuffiness - diarrhea

10. List the specific antidote for this toxin: Cyanide
The PT.
- Nitrate - hydroxocobalamin thiosulfate
Atropine would also block the receptors in the ciliary muscle - causing an impairment in accommodation (cycloplegia).
1. Streptokinase 2. Urokinase 3. tPA (alteplase) - APSAC (anistreplase)

11. Which drug(s) cause this reaction: Pulmonary fibrosis(3)?
- Ethosuxamide - sulfonamides - lamotrigine
hypokalemia - slight hyperlipidemia - hyperuricemia - lassitude - hypercalcemia - hyperglycemia
- Bleomycin - amiodarone - busulfan
Beta -2 agonist.

12. Resistance mechanisms for Tetracycline
Early myocardial infarction.
1. Better bioavailability 2. 2 to 4 times longer half life 3. Can be administered subcutaneously 4. Does not require laboratory monitoring
- DNA intercalator - Hodgkin's - myeloma - sarcoma - and solid tumors - Cardiotoxicity & alopecia
Decreased uptake or Increased transport out of cell

13. Name two bile acid resins.
cholestyramine - colestipol
Only in limited amounts
viral kinase
Disulfiram - like reaction with EtOH - Headache

14. What is the mechanism of Tacrolimus (FK506)?
Similar to cyclosporine; binds to FK- binding protein - inhibiting secretion of IL-2 and other cytokines.
Giant Roundworm (Ascaris) - Hookworm (Necator/Ancylostoma) - Pinworm (Enterobius)
It must be Phosphorylated by Viral Thymidine Kinase
- MT polymerization stabilizer - Ovarian & breast CA - Myelosupperession & hypersensitivity.

15. How does dantrolene work?
Indirect agonist - uptake inhibitor
Prevents the release of calcium from the sarcoplasmic reticulum of skeletal muscle.
Blastomyces - Coccidioides - Histoplasma - C. albicans; Hypercortisolism
Blocking muscarinic receptors in the circular fibers of the eye - results in unopposed action of radial muscles to dilate.

16. Antiarrhythmic class IV- primary site of action?
AV nodal cells
Intrathecally
Acts as a wide spectrum carbapenem
Forms toxic metabolites in the bacterial cell - Bactericidal

17. What is a sign of toxicity with the use of thrombolytics?
Bleeding.
compensatory tachycardia - fluid retention - lupus - like syndrome
The only local anesthetic with vasoconstrictive properties.
Local anesthetic.

18. Why is Cilastatin administered with Imipenem?
Diarrhea
To inhibit renal Dihydropeptidase I and decrease Imipenem inactivation in the renal tubules
It affects beta receptors equally and is used in AV heart block (rare).
Glycoproteins from leukocytes that block various stages of viral RNA and DNA synthesis

19. Antiarrhythmic class IC- effects?
NO AP duration effect. useful in V- tach that progresses to V- fib and in intractable SVT Last RESORT
Prevents release of mediators from mast cells. Effective only for the prophylaxis of asthma. Not effective during an acute attack.
orthostatic and exercise hypotension - sexual dysfunction - diarrhea
penicillinase resistant

20. K+- clinical use?
depresses ectopic pacemakers - especially in digoxin toxicity
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
Nonspecific beta - agonist; desired effect is the relaxation of bronchial smooth muscle (Beta 2). Adverse effect is tachycardia (Beta 1).
Inhibits organification and coupling of thyroid hormone synthesis. Also decreases peripheral conversion of T4 to T3.

21. List the specific antidote for this toxin: Anticholinesterases (organophosphate.)
Antifungal.
Gram + cocci - Proteus mirabilis - E. coli - Klebsiella pneumoniae (PEcK)
- Atropine & pralidoxime
Increases mean - systolic - and diastolic bp - while there is little change in pulse pressure.

22. What is the memory key for the effect of aluminum hydroxide overuse?
Inhibits bacterial Dihydrofolate Reductase - Bacteriostatic
AluMINIMUM amount of feces.
Methicillin - Nafcillin - and Dicloxacillin
- inhibits HGPRT (pur. Syn.) - Luk - Lymph

23. What is the MOA of Amantadine?
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
Liver
Blocks viral penetration/uncoating; may act to buffer the pH of the endosome
Sulfonamide Loop Diuretic. Inhibits ion co - transport system of thick ascending loop. Abolishes hypertonicity of the medulla - thereby preventing concentration of the urine.

24. What is the clinical use of Tacrolimus (FK506)?
Potent immunosuppressive used in organ transplant recipients.
Cephalosporin: 1) has a 6 member ring attached to the Beta lactam instead of a 5 member ring 2)has an extra functional group ( attached to the 6 member ring)
Benzathine penicillin G
Pretreat with antihistamines and a slow infusion rate

25. What is the MOA for Vancomycin?
loop diuretics - thiazides
Staphlococcus aureus
Inhibits cell wall mucopeptide formation - Bactericidal
Dry flushed skin - due to inhibition of sympathetic post - ganglionic blockade on muscarinic receptors of sweat glands. All others are opposite of What would be expected.

26. A 57 yo heart failure pt develops cardiac decompensation - What drug will give you adequate perfusion of his kidneys as well as tx for his Hypotension
proximal convoluted tubule
Inhibits IMP Dehydrogenase (competitively) - and therefore blocks Guanine Nucleotide synthesis
Cilastatin
Dopamine

27. Which drug(s) cause this reaction: Gray baby syndrome?
Competitive inibitor of progestins at progesterone receptors.
Penicillin - V
Md= (CpxCL)/F Cp= plas. Conc. CL=clear. F=bioaval.
- Chloramphenicol

28. What additional side effects exist for Ampicillin?
edrophonium (extremely short acting anticholinesterase)
DHPG (dihydroxy-2- propoxymethyl guanine)
Pretreat with antihistamines and a slow infusion rate
Rash - Pseudomembranous colitis

29. Adverse effects of Clonidine?
Acetylcholinesterase; ACh is broken down into choline and acetate.
dry mouth - sedation - severe rebound hypertension
Rare.
GI upset

30. What is the clinical use for Sucralfate?
Blocks Norepi - but not Dopamine
NO HYPERURICEMIA - NO SULFA AllERGY; same as furosemide otherwise
- acetylation - glucuron. - & sulfation - Conjugation - Polar product
Peptic ulcer disease.

31. What is the MOA of Aztreonam?
all except the K+ sparing diuretics Spironolactone - Triamterene - Amiloride
Inhalational general anesthetic.
Inhibits cell wall synthesis ( binds to PBP3). A monobactam
Dopamine; causes its release from intact nerve terminals

32. What is the MOA for Trimethoprim (TMP)?
- Penicillamine
Inhibits bacterial Dihydrofolate Reductase - Bacteriostatic
1. Cimetadine 2. Ranitidine 3. Famotidine 4. Nizatidine
1. Antipyretic 2. Analgesic 3. Anti - inflammatory

33. What are two Glitazones?
Mechanism unknown; possibly inhibits gluconeogenesis and increases glycolysis; effect is to decrease serum glucose levels
- Physostigmine salicylate
1. Pioglitazone 2. Rosiglitazone.
Centrally acting alpha agonist - thus causing a decrease in central adrenergic outflow - spairing renal blood flow

34. What is the clinical use for Ampicillin and Amoxicillin?
anuria - CHF
Foscarnet = pyroFosphate analog
Extended spectrum penicillin: certain Gram + bacteria and Gram - rods
penicillinase resistant

35. A fellow passenger on a Carnival cruise ship looks pale and diaphoretic - What antimuscarinic agent would you give them?
Fever/Chills - Hypotension - Nephrotoxicity - Arrhythmias
Inhibits xanthine oxidase - decresing conversion of xanthine to uric acid.
scopolamine
- Penicillamine

36. What is the formula for Volume of distribution (Vd)
Vd= (Amt. of drug in body/ Plasma drug conc.)
VACUUM your Bed Room'
Increase target cell response to insulin.
diuretics - sympathoplegics - vasodilators - ACE inhibitors - Angiotensin II receptor inhibitors

37. What is Ketoconazole specifically used for?
1. Mycobacterium tuberculosis 2. Delays resistance to Dapsone When used of Leprosy 3. Used in combination with other drugs
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.)
Blastomyces - Coccidioides - Histoplasma - C. albicans; Hypercortisolism
Aminoglycosides

38. Which diuretics decrease urine Ca2+?
Amphetamine and Ephedrine
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.
thiazides - amiloride
1. Addison's disease 2. Inflammation 3. Immune suppression 4. Asthma

39. IV Penicillin
Amphotericin B - Nystatin - Fluconazole/azoles
Sulfamethoxazole (SMZ) - Sulfisoxazole - Triple sulfas - Sulfadiazine
constipation - flushing - edema - CV effects (CHF - AV block - sinus node depression) - and torsade de pointes (Bepridil)
Penicillin - G

40. How is Amphotericin B administered for fungal meningitis?
- Tricyclic antidepressants
Intrathecally
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.)
Gram + cocci - Gram - rods - and Anerobes

41. Clonidine is the preferred sym pathomimetic tx of HTN in pts with renal disease - why??
Centrally acting alpha agonist - thus causing a decrease in central adrenergic outflow - spairing renal blood flow
cross - allergenic
None. No - because atropine would block the postganglionic muscarinic receptors involved in sweat gland stimulation.
vascular sm. Mus.: Nifedipine>Diltiazem>Verapamil

42. List the specific antidote for this toxin: Carbon monoxide
- Daunorubicin & Doxorubicin
-100% oxygen - hyperbaric
Na/K ATPase
Ataxia - Dizziness - Slurred speech

43. List the specific antidote for this toxin: Salicylates
torsade de pointes
Protamine sulfate
- Alkalinize urine & dialysis
- partial agonist can have increased - decreased - /A21or equal potency as full agonist. - Potency is an independent factor.

44. Furosemide - clinical use?
- Physostigmine salicylate
edematous states (CHF - cirrhosis - nephrotic syndrome - pulm edema) - HTN - hypercalcemia
None. No - because atropine would block the postganglionic muscarinic receptors involved in sweat gland stimulation.
- Daunorubicin & Doxorubicin

45. What is used to reverse the action of Heparin?
Protamine Sulfate is used for rapid reversal of heparinization (positively charged molecule that binds to negatively charged heparin).
Antibiotic - protein synthesis inhibitor.
None. No - because atropine would block the postganglionic muscarinic receptors involved in sweat gland stimulation.
- Isoniazid

46. For Warfarin What is the Duration of action
- Cloazapine - carbamazapine - colchicine - PTU
Chronic (weeks or months)
Diuresis in pateints with sulfa allergy
- Daunorubicin & Doxorubicin

47. What are the major toxic side effects of Imipenem/cilastatin?
Prevents the release of Ca from SR of skeletal muscle
To inhibit renal Dihydropeptidase I and decrease Imipenem inactivation in the renal tubules
1. Peptic ulcer 2. Gastritis 3. Esophageal reflux 4. Zollinger - Ellison syndrome
GI distress - Skin rash - and Seizures at high plasma levels

48. Amiodarone - toxicity?
1) Aminoglycosides = bactericidal 2) Tetracyclines = bacteriostatic
Paranteral (IV - SC)
- Hydralazine - Procainamide - INH - phenytoin
pulmonary fibrosis - corneal deposits - hepatotoxicity - skin deposits resulting in photodermatitis - neurologic effects - consitpation - CV (bradycardia - heart block - CHF) - and hypo - or hyperthyroidism.

49. List the specific antidote for this toxin: Antimuscarinic (anticholinergic)
Early myocardial infarction.
1) Chloramphenical = bacteriostatic 2) Erythromycin = bacteriostatic 3) Lincomycin = bacteriostatic 4)cLindamycin = bacteriostatic
- Physostigmine salicylate
Chronic anticoagulation.

50. What is the MOA of Isoniazid (INH)?
Inhibits Viral DNA polymerase
Decreases synthesis of Mycolic Acid
When pts have Low CD4+ (< 500 cells/cubic mm) or a High Viral Load
- Hypersensitivity reactions - Hemolysis - Nephrotoxicity (tubulointerstitial nephritis) - Kernicterus in infants Displace other drugs from albumin (e.g. - warfarin)