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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.
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. Which drug(s) cause this reaction: Disulfram - like reaction (4) ?
- Metronidazole - certain cephalosporins - procarbazine - sulfonylureas
Rifampin (DOC) - minocycline
- B51Naloxone / naltrexone (Narcan)
Keratin containing tissues - e.g. - nails

2. Digoxin v. Digitoxin: protein binding?
Digitoxin 168hrs Digoxin 40 hrs
- Chloramphenicol
Digitoxin 70% Digoxin 20-40%
- Vitamin K & fresh frozen plasma

3. List the specific antidote for this toxin: Opioids
- B51Naloxone / naltrexone (Narcan)
- Formaldehyde & formic acid - severe acidosis & retinal damage
- Cloazapine - carbamazapine - colchicine - PTU
- Glucocorticoid withdrawal

4. What patients are at risk for life threatening hypotension When taking Sildenafil (Viagra)?
Those patients who are taking nitrates.
penicillinase resistant
Increases mean - systolic - and diastolic bp - while there is little change in pulse pressure.
TCA

5. ACE inhibitors - mechanism?
Prefers beta's at low doses - but at higher doses alpha agonist effects are predominantly seen.
Rifampin - Ethambutol - Streptomycin - Pyrazinamide - Isoniazid (INH)
Staphlococcus aureus
reduce levels of Angiotensin II - thereby preventing the inactivation of bradykinin (a potent vasodilator); renin level is increased

6. List the specific antidote for this toxin: Antimuscarinic (anticholinergic)
Premature infants - because they lack UDP- glucuronyl transferase
Cyclooxygenases (COX I - COX II).
Bactericidal for: Gram + rod and cocci - Gram - cocci - and Spirochetes
- Physostigmine salicylate

7. Digoxin v. Digitoxin: half life?
Zidovudine (AZT) - Didanosine (ddI) - Zalcitabine (ddC) - Stavudine (d4T) - Lamivudine (3TC)
Digitoxin 168hrs Digoxin 40 hrs
1. Bleeding 2. Teratogenicity 3. Drug - drug interactions
bradycardia - AV block - CHF

8. Which drug(s) cause this reaction: Cutaneous flushing (4)?
toxic
RESPIre
- Niacin - Ca++ channel blockers - adenosine - vancomycin
Same as penicillin. Act as narrow spectrum antibiotics

9. What is the mechanism of action of Acetaminophen?
Epinephrine
No - hemicholinum block the uptake of Choline and thus Ach synthesis
Reversibly inhibits cyclooxygenase - mostly in CNS. Inactivated peripherally.
NO AP duration effect. useful in V- tach that progresses to V- fib and in intractable SVT Last RESORT

10. What are the clinical uses for Imipenem/cilastatin?
- Tetracycline - amiodarone - sulfonamides
- Corticosteroids - heparin
Penicillin - Cephalosporins - Vancomycin - Aminoglycosides - Fluoroquinolones - Metronidazole
Gram + cocci - Gram - rods - and Anerobes

11. Why are the Sulfonylureas inactive in IDDM (type -1)?
Glycoproteins from leukocytes that block various stages of viral RNA and DNA synthesis
- Normalize K+ - Lidocaine - & Anti - dig Mab
Because they require some residual islet function.
Dopamine

12. For Heparin What is the Mechanism of action
CMV Retinitis in IC pts When Ganciclovir fails
thiazides - amiloride
1. Peptic ulcer 2. Gastritis 3. Esophageal reflux 4. Zollinger - Ellison syndrome
Activates antithrombin III

13. How would you treat African Trypanosomiasis (sleeping sickness)?
- Methylene blue
Suramin
Decreases synthesis of Mycolic Acid
Topical and Oral - for Oral Candidiasis (Thrush)

14. How is Amphotericin B administered for fungal meningitis?
Depolymerizes microtubules - impairing leukocyte chemotaxis and degranulation.
1. Cimetadine 2. Ranitidine 3. Famotidine 4. Nizatidine
Intrathecally
Albuterol - tertbutaline

15. What organism is Imipenem/cilastatin the Drug of Choice for?
Enterobacter
edrophonium (extremely short acting anticholinesterase)
GI discomfort
- B51Naloxone / naltrexone (Narcan)

16. These drugs acts indirectly by releasing strored catecholamines in the presynaptic terminal
Sucralfate cannot work in the presence of antacids or H2 blockers because it requires an acidic environment to polymerize.
Mechanism unknown; possibly inhibits gluconeogenesis and increases glycolysis; effect is to decrease serum glucose levels
Amphetamine and Ephedrine
- Tamoxifen

17. Which drug(s) cause this reaction: Atropine - like side effects?
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.
- Tricyclic antidepressants
Carbachol - pilocarpine - physostigmine - echothiophate
fetal renal toxicity - hyperkalemia - Cough - Angioedema - Proteinuria - Taste changes - hypOtension - Pregnancy problems - Rash - Increased renin - Lower Angiotensin II (CAPTOPRIL)

18. What is the MOA of Ganciclovir?
Inhibits CMV DNA polymerase
Aminoglycosides
Bacitracin - Vancomycin
AluMINIMUM amount of feces.

19. What is the lab value used to monitor the effectiveness of Warfarin therapy?
The PT.
very short acting
anticholinesterase glaucoma
AV nodal cells

20. Adverse effects of Hydralazine?
- Quinidine - quinine
Because they require some residual islet function.
nausea - headache - lupus - like syndrome - reflex tachycardia - angina - salt retention
Acetaminophen has antipyretic and analgesic properties - but lacks anti - inflammatory properties.

21. What are the major toxic side effects of Imipenem/cilastatin?
GI upset - Superinfections - Skin rashes - Headache - Dizziness
Decreases synthesis of Mycolic Acid
Ganciclovir is more toxic to host enzymes
GI distress - Skin rash - and Seizures at high plasma levels

22. What is the category of drug names ending in - pril (e.g. Captopril)
Because they require some residual islet function.
Bactericidal for: Gram + rod and cocci - Gram - cocci - and Spirochetes
ACE inhibitor.
impotence - exacerbation of asthma - CV effects - CNS effects - may mask hypoclycemia

23. How is Rifampin used clinically?
1. Mycobacterium tuberculosis 2. Delays resistance to Dapsone When used of Leprosy 3. Used in combination with other drugs
Beta Blockers
YES
Inhibit DNA Gyrase (topoisomerase II) - Bactericidal

24. Your patient wants an effective drug to treat his motion sickness - What would you prescribe
Scopolamine
Fast vs. Slow Acetylators
BM suppression (neutropenia - anemia) - Peripheral neuropathy
GI upset - Superinfections - Skin rashes - Headache - Dizziness

25. Name two LPL stimulators.
1. Addison's disease 2. Inflammation 3. Immune suppression 4. Asthma
- Methotrexate - 5 FU - 6 mercaptopurine
Ciprofloxacin - Norfloxacin - Ofloxacin - Grepafloxacin - Enoxacin - Nalidixic acid
Gemfibrozil - Clofibrate

26. What is the MOA for Ampicillin and Amoxicillin?
DOC in diagnosing and abolishing AV nodal arrhythmias
- Methylene blue
1. RNA pol inhibitor 2. Revs up P450 3. Red/orange body fluids 4. Rapid resistance if used alone
Same as penicillin. Extended spectrum antibiotics

27. What is the category of drug names ending in - operidol (e.g. Haloperidol)
GI distress - Tooth discoloration and Inhibition of bone growth in children - Fanconi's syndrome - Photosensitivity
Indirect agonist - uptake inhibitor
Butyrophenone (neuroleptic).
1. Heavy bleeding 2. GI effects (n/v - anorexia) 3. Abdominal pain

28. What type of patient should not take Misoprostol and why?
- Tricyclic antidepressants
Local anesthetic.
Beta1 more than B2
Misoprostol is contraindicated in women of childbearing potential because it is an abortifacient.

29. What is an additional side effect of Methicillin?
Cimetidine is a potent inhibitor of P450; it also has an antiandrogenic effect and decreases renal excretion of creatinine. Other H2 blockers are relatively free of these effects.
Slow - limited by half lives of clotting factors
Modification via Acetylation - Adenylation - or Phosphorylation
Interstitial nephritis

30. What is a sign of toxicity with the use of thrombolytics?
Captopril - Enalapril - Lisinopril
Benzodiazepine.
- Niacin - Ca++ channel blockers - adenosine - vancomycin
Bleeding.

31. Verapamil has similar action to?
Beta Blockers
They inhibit reuptake of NE at the nerve terminal (as does cocaine).
- Nitrate - hydroxocobalamin thiosulfate
- Formaldehyde & formic acid - severe acidosis & retinal damage

32. How does Ganciclovir's toxicity relate to that of Acyclovir?
proximal convoluted tubule
Ganciclovir is more toxic to host enzymes
Diarrhea
Inhibit viral DNA polymerase

33. Is toxicity rare or common whith Cromolyn used in Asthma prevention?
Staphlococcus aureus and Clostridium difficile (pseudomembranous colitis)
Rare.
Useful in muscle paralysis during surgery or mechanical ventilation.
Early myocardial infarction.

34. Foscarnet toxicity?
Increases coumadin metabolism
Nephrotoxicity
Only in limited amounts
Hypersensitivity reactions

35. Antiarrhythmic class II- mechanism?
Used in combination therapy with SMZ to sequentially block folate synthesis
all except the K+ sparing diuretics Spironolactone - Triamterene - Amiloride
blocking the beta adrenergic receptor leads to decreased cAMP - and decreased Ca2+ flux
Protamine sulfate

36. Would blockade of muscarininc receptors in the bladder be useful in treating urinary retention?
Beta - lactamase cleavage of Beta - lactam ring
No. Atropine is used to reduce urgency in mild cystitis. So it would aggravate the urinary retention.
Imipenem
GET on the Metro

37. How do Sulfonamides act on bacteria?
Acute gout.
YES
Staphlococcus aureus
As PABA antimetabolites that inhibit Dihydropteroate Synthase - Bacteriostatic

38. List the mechanism - clinical use - & toxicity of Paclitaxel.
- MT polymerization stabilizer - Ovarian & breast CA - Myelosupperession & hypersensitivity.
Modification via Acetylation - Adenylation - or Phosphorylation
- Cimetidine - ketoconazole - spironolactone - digitalis - EtOH - estrogens
Acute coronary syndrome; coronary stenting. Decreases the incidence or recurrence of thrombotic stroke.

39. What can result due to antacid overuse?
Carbenicillin - Piperacillin - and Ticarcillin
AZT
GI distress - Tooth discoloration and Inhibition of bone growth in children - Fanconi's syndrome - Photosensitivity
Can affect absorption - bioavailability - or urinary excretion of other drugs by altering gastric and urinary pH or by delaying gastric emptying.

40. What are the major structural differences between Penicillin and Cephalosporin?
new arrhythmias - hypotension
Rheumatoid and osteoarthritis.
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)
sedation - depression - nasal stuffiness - diarrhea

41. Which drug(s) cause this reaction: Hot flashes?
decrease myocardial O2 consumption by: 1- decreasing end diastolic volume 2- decreasing BP 3- decreasing HR 4- decreasing contractility 5- decreasing ejection time
check PFTs - LFTs - and TFTs
viral kinase
- Tamoxifen

42. Furosemide increases the excretion of What ion?
Pyridoxine (B6) administration
- polymyxins
Ca2+ (Loops Lose calcium)
edematous states (CHF - cirrhosis - nephrotic syndrome - pulm edema) - HTN - hypercalcemia

43. What is the MOA of Amantadine?
Succinylcholine
Blocks viral penetration/uncoating; may act to buffer the pH of the endosome
Gram + - Gram - - Norcardia - Chlamydia
- Ethanol - dialysis - & fomepizole

44. Name the common Aminoglycosides (5)
edrophonium (extremely short acting anticholinesterase)
Gentamicin - Neomycin - Amikacin - Tobramycin - Streptomycin
Diuresis in pateints with sulfa allergy
- ACE inhibitors (Losartan>no cough)

45. How do you treat coma in the ER (4)?
- Airway - Breathing - Circulation - Dextrose (thiamine & narcan) - ABCD
Antileukotriene; blocks leukotriene receptors.
Ceftriaxone
Increases mean - systolic - and diastolic bp - while there is little change in pulse pressure.

46. Which diuretics cause alkalosis?
loop diuretics - thiazides
Misoprostol is contraindicated in women of childbearing potential because it is an abortifacient.
AZT
BM suppression (neutropenia - anemia) - Peripheral neuropathy

47. Which cancer drugs work at the level of mRNA(2)?
1. Peptic ulcer 2. Gastritis 3. Esophageal reflux 4. Zollinger - Ellison syndrome
Acetaminophen has antipyretic and analgesic properties - but lacks anti - inflammatory properties.
GET on the Metro
- Steroids - Tamoxifen

48. What are are the Sulfonylureas (general description) and What is their use?
Modification via Acetylation - Adenylation - or Phosphorylation
GI distress - Skin rash - and Seizures at high plasma levels
- Halothane - Valproic acid - acetaminophen - Amantia phalloides
Sulfonylureas are oral hypoglycemic agents - they are used to stimulate release of endogenous insulin in NIDDM (type -2).

49. How is Amphotericin B used clinically?
Severe Gram - rod infections.
Wide spectrum of systemic mycoses: Cryptococcus - Blastomyces - Coccidioides - Aspergillus - Histoplasma - Candida - Mucor
Acetylcholinesterase; ACh is broken down into choline and acetate.
Hemolytic anemia

50. How does angiotensin II affect NE release?
- Airway - Breathing - Circulation - Dextrose (thiamine & narcan) - ABCD
Pentavalent Antimony
- Vinca alkaloids(inhibit MT) - Paclitaxel
It acts presynaptically to increase NE release.