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 MOA for Metronidazole?
Constant FRACTION eliminated per unit time.(exponential)
Increased systolic and pulse pressure - decreased diastolic pressure - and little change in mean pressure.
increase AP duration - increase ERP - increase QT interval - for use When other arrhythmics fail
Forms toxic metabolites in the bacterial cell - Bactericidal

2. What is the mechanism of action of Aspirin?
1. Bleeding 2. Thrombocytopenia 3. Drug - drug interactions
Acetylates and irreversibly inhibits cyclooxygenase (COX I and COX II) to prevent the conversion of arachidonic acid to prostaglandins.
Finasteride inhibits 5 Alpha - reductase - this decreases the conversion of testosterone to dihydrotestosterone - useful in BPH
depresses ectopic pacemakers - especially in digoxin toxicity

3. List the specific antidote for this toxin: Iron
- Deferoxamine
increase AP duration - increase ERP - increase QT interval - for use When other arrhythmics fail
Sulfamethoxazole (SMZ) - Sulfisoxazole - Triple sulfas - Sulfadiazine
- Tetracycline - amiodarone - sulfonamides

4. List the mechanism - clinical use - & toxicity of Tamoxifen.
- Estrogen receptor antagonist - Breast CA - increased endometrial CA risk
Hexamethonium is a nicotinic antagonist - and thus is a ganglionic blocker.
Norepinephrine (Alpha1 -2 and beta 1)
Finasteride inhibits 5 Alpha - reductase - this decreases the conversion of testosterone to dihydrotestosterone - useful in BPH

5. What is the memory key involving the '4 R's of Rifampin?'
As an anticholinesterase it increases endogenous ACh and thus increases strength.
Antiprotozoal: Giardia - Entamoeba - Trichomonas - Gardnerella vaginalis Anaerobes: Bacteroides - Clostridium
1. RNA pol inhibitor 2. Revs up P450 3. Red/orange body fluids 4. Rapid resistance if used alone
Beta 2 agonist; desired effect is the relaxation of bronchial smooth muscle (Beta 2). Use during acute exacerbation.

6. Antimicrobial prophylaxis for Gonorrhea
Ceftriaxone
1. Streptokinase 2. Urokinase 3. tPA (alteplase) - APSAC (anistreplase)
- N- acetylcystine
GET on the Metro

7. List the specific antidote for this toxin: Acetaminophen
competitive inhibirot of aldosterone in the cortical collecting tubule
- N- acetylcystine
These B-2 agonists cause respiratory smooth muscle to relax.
- Vinca alkaloids(inhibit MT) - Paclitaxel

8. Which drug(s) cause this reaction: P450 induction(6)?
- Barbiturates - phenytoin - carbamazipine - rifampin - griseofulvin - quinidine
cardiac muscle: Verapamil>Diltiazem>Nifedipine
- Hypersensitivity reactions - Hemolysis - Nephrotoxicity (tubulointerstitial nephritis) - Kernicterus in infants Displace other drugs from albumin (e.g. - warfarin)
Edrophonium

9. When is HIV therapy initiated?
Hexamethonium is a nicotinic antagonist - and thus is a ganglionic blocker.
edrophonium (extremely short acting anticholinesterase)
- MT polymerization stabilizer - Ovarian & breast CA - Myelosupperession & hypersensitivity.
When pts have Low CD4+ (< 500 cells/cubic mm) or a High Viral Load

10. MOA: Disrupt bacterial/fungal cell membranes
Polymyxins
The PT.
decrease AP duration - affects ischemic or depolarized Purkinje and ventricular system
Blastomyces - Coccidioides - Histoplasma - C. albicans; Hypercortisolism

11. What is the MOA for the Azoles?
1. RNA pol inhibitor 2. Revs up P450 3. Red/orange body fluids 4. Rapid resistance if used alone
Inhibit Ergosterol synthesis
Chagas' disease - American Trypanosomiasis (Trypanosoma cruzi)
Theoretically it could be used to block the cephalic phase of acid secretion (vagal stimulation).

12. Name common Polymyxins
Indomethacin is used to close a patent ductus arteriosus.
Polymyxin B - Polymyxin E
increased AP duration - increased ERP increased QT interval. Atrial and ventricular.
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

13. What is the MOA of Amantadine?
- N- acetylcystine
Inhibit RT of HIV and prevent the incorporation of viral genome into the host DNA
AZT
Blocks viral penetration/uncoating; may act to buffer the pH of the endosome

14. Adverse effects of Methyldopa?

Warning: Invalid argument supplied for foreach() in /var/www/html/basicversity.com/show_quiz.php on line 183

15. List the mechanism - clinical use - & toxicity of Etoposide.
Protamine Sulfate is used for rapid reversal of heparinization (positively charged molecule that binds to negatively charged heparin).
- Lithium
Short.
- Topo II inhibitor(GII specific) - Oat cell of Lung & prostate - & testicular - Myelosuppression & GI irritation.

16. What are three toxicities of Leuprolied?
Penicillin - Ampicillin - Ticarcillin - Pipercillin - Imipenem - Aztreonam - Cephalosporins
1. Antiandrogen 2. Nausea 3. Vomiting
- Chloramphenicol
- Ethanol - dialysis - & fomepizole

17. What do you treat Nematode/roundworm (pinworm - whipworm) infections with?
Succinylcholine
Mebendazole/Thiabendazole - Pyrantel Pamoate
1. Acarbose 2. Miglitol
Oxygen

18. Which drug(s) cause this reaction: Cardiac toxicity?
Acetaminophen has antipyretic and analgesic properties - but lacks anti - inflammatory properties.
- Daunorubicin & Doxorubicin
Md= (CpxCL)/F Cp= plas. Conc. CL=clear. F=bioaval.
edrophonium (extremely short acting anticholinesterase)

19. Adverse effects of Captopril?
fetal renal toxicity - hyperkalemia - Cough - Angioedema - Proteinuria - Taste changes - hypOtension - Pregnancy problems - Rash - Increased renin - Lower Angiotensin II (CAPTOPRIL)
Inhibits platelet aggregation by irreversibly inhibiting the ADP pathway involved in the binding of fibrinogen.
Spironolactone - Triamterene - Amiloride (the K+ STAys)
1. Significant: nephrotoxicity 2. Peripheral neuropathy 3. Hypertension 4. Pleural effusion 5. Hyperglycemia.

20. Which RT inhibitor causes Megaloblastic Anemia?
Immediate anticoagulation for PE - stroke - angina - MI - DVT.
increased AP duration - increased ERP increased QT interval. Atrial and ventricular.
AZT
Muscarinic antagonist; competatively blocks muscarinic receptors - preventing bronchoconstriction.

21. ___________ are Teratogenic
Aminoglycosides
Can affect absorption - bioavailability - or urinary excretion of other drugs by altering gastric and urinary pH or by delaying gastric emptying.
Useful in muscle paralysis during surgery or mechanical ventilation.
IV vitamin K and fresh frozen plasma

22. What Sulfonamides are used for simple UTIs?
Rifampin (DOC) - minocycline
Triple sulfas or SMZ
Neutropenia
Aminoglycosides

23. Are Ampicillin and Amoxicillin are not...
penicillinase resistant
- Deferoxamine
- Physostigmine salicylate
very short acting

24. List the mechanism - clinical use - & toxicity of Cyclophosphamide.
Muscarinic antagonist; competatively blocks muscarinic receptors - preventing bronchoconstriction.
loop diuretics - spironolactone
- Alkalating agent - NHL - Breast - ovary - & lung. - Myelosuppression - & hemorrhagic cystitis.
Inhibits CMV DNA polymerase

25. 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
Blocking muscarinic receptors in the circular fibers of the eye - results in unopposed action of radial muscles to dilate.
Dopamine
Treatment of hypertension - especially with renal disease (lowers bp centrally - so flow is maintained to kidney).
Reversible block of histamine H2 receptors

26. How is Amphotericin B used clinically?
Babiturate.
Does not cross
NO
Wide spectrum of systemic mycoses: Cryptococcus - Blastomyces - Coccidioides - Aspergillus - Histoplasma - Candida - Mucor

27. Which individuals are predisposed to Sulfonamide - induced hemolysis?
Inhibits formation of Initiation Complex - causes misreading of mRNA - Bactericidal
G6PD deficient individuals
- Constant AMOUNT eliminated per unit time. - Etoh & ASA
Digoxin=urinary Digitoxin=biliary

28. Adverse effects of Hydrochlorothiazide?
hypokalemia - slight hyperlipidemia - hyperuricemia - lassitude - hypercalcemia - hyperglycemia
impotence - exacerbation of asthma - CV effects - CNS effects - may mask hypoclycemia
Blocks Peptide Bond formation at the 50S subunit - Bacteriostatic
Digitoxin>95% Digoxin 75%

29. What cholinomimetics might your pt be taking for his glaucoma
Beta 2 agonist; used as a long - acting agent for prophylaxis. Adverse effects are tremor and arrhythmia.
Carbachol - pilocarpine - physostigmine - echothiophate
Oxygen
Overdose produces hepatic necrosis; acetaminophen metablolite depletes glutathione and forms toxic tissue adducts in liver.

30. What are the clinical uses for Aztreonam?
Doxycycline - because it is fecally eliminated
Botulinum
Zidovudine (AZT) - Didanosine (ddI) - Zalcitabine (ddC) - Stavudine (d4T) - Lamivudine (3TC)
Gram - rods: Klebsiella species - Pseudomonas species - Serratia species

31. What are two mechanisms of action of Propythiouracil?
amphetamine and ephedrine
1. Hot flashes 2. Ovarian enlargement 3. Multiple simultaneous pregnancies 4. Visual disturbances
Methylzanthine; desired effect is bronchodilation - may cause bronchodilation by inhibiting phosphodiesterase - enzyme involved in degrading cAMP (controversial).
Inhibits organification and coupling of thyroid hormone synthesis. Also decreases peripheral conversion of T4 to T3.

32. Which RT inhibitors cause a Rash?
1. Aluminum hydroxide: constipation and hypophosphatemia 2. Magnesium hydroxide: diarrhea 3. Calcium carbonate: Hypercalcemia - rebound acid increase - All may cause hypokalemia
1. Mycobacterium tuberculosis 2. Delays resistance to Dapsone When used of Leprosy 3. Used in combination with other drugs
Non - Nucleosides
Md= (CpxCL)/F Cp= plas. Conc. CL=clear. F=bioaval.

33. Name two LPL stimulators.
Flutamide is a nonsteroidal competitive inhibitor of androgens at the testosterone receptor - used in prostate carcinoma.
Mechanism unknown; possibly inhibits gluconeogenesis and increases glycolysis; effect is to decrease serum glucose levels
Gemfibrozil - Clofibrate
GI discomfort - Acute cholestatic hepatitis - Eosinophilia - Skin rashes

34. What is the MOA for the Aminoglycosides?
Flutamide is a nonsteroidal competitive inhibitor of androgens at the testosterone receptor - used in prostate carcinoma.
Nucleosides
Yes
Inhibits formation of Initiation Complex - causes misreading of mRNA - Bactericidal

35. The COX-2 inhibitors (celecoxib - rofecoxib) have similar side effects to the NSAIDs with What one exception?
- aminoglycosides - loop diuretics - cisplatin
The COX-2 inhibitors should not have the corrosive effects of other NSAIDs on the gastrointestinal lining.
Receptors = D1=D2>beta>alpha - thus increasing heart rate (beta) and blood pressure (alpha vasoconstriction) while maintaining kidney perfusion (dopamine receptors)
Oral

36. Preferential action of the Ca2+ channel blockers at vascular smooth muscle?
vascular sm. Mus.: Nifedipine>Diltiazem>Verapamil
- Shifts the curve to the right - increases Km
hyperaldosteronism - K+ depletion - CHF
Hypersensitivity reactions

37. How does a competitive antagonist effect an agonist?
Inhibt Assembly of new virus by Blocking Protease Enzyme
- Shifts the curve to the right - increases Km
Binds to the Pyrophosphate Binding Site of the enzyme
- Flumazenil

38. What are common side effects of RT Inhibitors?
BM suppression (neutropenia - anemia) - Peripheral neuropathy
Acetylcholine esterase
1. Bleeding 2. Thrombocytopenia 3. Drug - drug interactions
- Methotrexate - 5 FU - 6 mercaptopurine

39. For Warfarin What is the Lab value to monitor
1. Antipyretic 2. Analgesic 3. Anti - inflammatory
Acute coronary syndrome; coronary stenting. Decreases the incidence or recurrence of thrombotic stroke.
Blocking muscarinic receptors in the circular fibers of the eye - results in unopposed action of radial muscles to dilate.
PT

40. List the specific antidote for this toxin: Opioids
anuria - CHF
- B51Naloxone / naltrexone (Narcan)
Sulfamethoxazole (SMZ) - Sulfisoxazole - Triple sulfas - Sulfadiazine
Blocks Norepi - but not Dopamine

41. How does a noncompetitive antagonist effect an agonist?
- Shifts the curve down - reduces Vmax
They inhibit reuptake of NE at the nerve terminal (as does cocaine).
1. Meningococcal carrier state 2. Chemoprophylaxis in contacts of children with H. influenzae type B
TMP- SMZ

42. What antimuscarinic drug is useful for the tx of asthma
With an amino acid change of D- ala D- ala to D- ala D- lac
osmotic diuretic - increase tubular fluid osmolarity - thereby increasing urine flow
Sulfamethoxazole (SMZ) - Sulfisoxazole - Triple sulfas - Sulfadiazine
Ipratropium

43. Beta Blockers - CNS toxicity?
- Protamine
edrophonium (extremely short acting anticholinesterase)
Pyridoxine (B6) administration
sedation - sleep alterations

44. Name three calcium channel blockers?
Neurotoxicity - Acute renal tubular necrosis
Nifedipine - Verapamil - Diltiazem
Non - Nucleosides
Sulfonylureas are oral hypoglycemic agents - they are used to stimulate release of endogenous insulin in NIDDM (type -2).

45. Name the common Nucleoside Reverse Transcriptase Inhibitors
Zidovudine (AZT) - Didanosine (ddI) - Zalcitabine (ddC) - Stavudine (d4T) - Lamivudine (3TC)
Aminoglycosides
Aluminum sucrose sulfate polymerizes in the acid environment of the stomach and selectively binds necrotic peptic ulcer tissue. Acts as a barrier to acid - pepsin - and bile.
Inhibits bacterial Dihydrofolate Reductase - Bacteriostatic

46. Name four Antiarrhythmic drugs in class III.
Blocks viral penetration/uncoating; may act to buffer the pH of the endosome
Receptors = D1=D2>beta>alpha - thus increasing heart rate (beta) and blood pressure (alpha vasoconstriction) while maintaining kidney perfusion (dopamine receptors)
Sotalol - Ibutilide - Bretylium - Amiodarone
Nephrotoxicity (esp. with Cephalosporins) - Ototoxicity (esp. with Loop Diuretics)

47. Are not penicillinase resistant
Cryptococcal meningitis in AIDS patients and Candidal infections of all types
GET on the Metro
Reserpine inhibits dopamine transport into vesicles - attenuating its conversion to NE by dopamine beta - hydroxylase.
Carbenicillin - Piperacillin - and Ticarcillin

48. List the specific antidote for this toxin: Arsenic (all heavy metals)
Keratin containing tissues - e.g. - nails
It must be Phosphorylated by Viral Thymidine Kinase
- Dimercaprol - succimer
Hypersensitivity reactions

49. List the mechanism - clinical use - & toxicity of Nitrosureas.
- Alkalate DNA - Brain tumors - CNS toxicity
first dose orthostatic hypotension - dizziness - headache
Cardiac glycoside (inotropic agent).
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

50. Which drug(s) cause this reaction: Cough?
- ACE inhibitors (Losartan>no cough)
competitive inhibirot of aldosterone in the cortical collecting tubule
Dobutamine has more of an affintiy for beta -1 than beta -2 - and is used for treating heart failure and shock. Albuterol and terbutaline is the reverse - and is used in treatment of acute asthma.
Beta Blockers