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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. Name three ACE inhibitors?
- Normalize K+ - Lidocaine - & Anti - dig Mab
Captopril - Enalapril - Lisinopril
Babiturate.
Modification via Acetylation - Adenylation - or Phosphorylation

2. What is Clindamycin used for clinically?
Blocks Peptide Bond formation at the 50S subunit - Bacteriostatic
Quinolones
Gemfibrozil - Clofibrate
Anaerobic infections (e.g. - B. fragilis - C. perfringens)

3. Aztreonam ________ to penicillinase
post MI and digitalis induced arrhythmias
- Tricyclic antidepressants
is resistant
Beta 2 agonist; desired effect is the relaxation of bronchial smooth muscle (Beta 2). Use during acute exacerbation.

4. What is the category - method of use - and adverse effects of Salmeterol in Asthma treatment?
- Antipsychotics
Early myocardial infarction.
Beta 2 agonist; used as a long - acting agent for prophylaxis. Adverse effects are tremor and arrhythmia.
Treatment of infertility.

5. Common toxicities associated with Fluoroquinolones?
GI upset - Superinfections - Skin rashes - Headache - Dizziness
Initially vasoconstriction would increase bp - but then it acts on central alpha -2 receptors to decrease adrenergic outflow resulting in decreased bp.
toxic
Antimetabolite derivative of 6- mercaptopurine that interferes with the metablolism and synthesis of nucleic acid.

6. List five common glucocorticoids.
1. Hydrocortisone 2. Predisone 3. Triamcinolone 4. Dexamethasone 5. Beclomethasone
block voltage dependent L- type Ca2+ channels of cardiac and smooth muscle - decreasing contractility
Inhibit intestinal bursh border Alpha - glucosidases; delayed hydrolysis of sugars and absorption of sugars leading to decresed postprandial hyperglycemia.
Minor hepatotoxicity - Drug interactions (activates P450)

7. What beta 2 agonist will help your 21yo Astma pt?
sedation - sleep alterations
1. Cimetadine 2. Ranitidine 3. Famotidine 4. Nizatidine
increase AP duration - increase ERP - increase QT interval - for use When other arrhythmics fail
Albuterol - tertbutaline

8. For Warfarin What is the Site of action
GI discomfort
Because they require some residual islet function.
Liver
- Tricyclic antidepressants

9. List the specific antidote for this toxin: Arsenic (all heavy metals)
Chronic gout.
- Dimercaprol - succimer
cholestyramine - colestipol
Clavulanic acid

10. Digoxin v. Digitoxin: bioavailability?
thick ascending limb
Digitoxin>95% Digoxin 75%
1. Acarbose 2. Miglitol
Aminoglycosides - Tetracyclines

11. What are three possible complications of Heparin therapy?
1. Bleeding 2. Thrombocytopenia 3. Drug - drug interactions
hyperchloremic metabolic acidosis - neuropathy - NH3 toxicity - sulfa allergy
Antiprotozoal: Giardia - Entamoeba - Trichomonas - Gardnerella vaginalis Anaerobes: Bacteroides - Clostridium
cross - allergenic

12. Amprotericin B ___________ the BBB
1. Cimetadine 2. Ranitidine 3. Famotidine 4. Nizatidine
Aminoglycosides - Tetracyclines
Misoprostol is a PGE1 analog that increases the production and secretion of the gastic mucous barrier.
Does not cross

13. Decrease Digitoxin dose in renal failure?
Decreased uptake or Increased transport out of cell
NE acts presynaptically on alpha -2 receptors to inhibit its own release. ACh also acts presynaptically through M1 receptors to inhibit NE release.
NO
1) Aminoglycosides = bactericidal 2) Tetracyclines = bacteriostatic

14. Quinidine - toxicity?
- Weak Acids>Alkinalize urine(CO3) to remove more - Weak bases>acidify urine to remove more
block Na+ channels in the cortical collecting tubule
Resistant Gram - infections
cinchonism: HA - tinnitus - thrombocytopenia - torsade de pointes due to increased QT interval

15. Why does atropine dilate the pupil?
Blocking muscarinic receptors in the circular fibers of the eye - results in unopposed action of radial muscles to dilate.
Receptors = D1=D2>beta>alpha - thus increasing heart rate (beta) and blood pressure (alpha vasoconstriction) while maintaining kidney perfusion (dopamine receptors)
INH: Injures Neurons and Hepatocytes
- Ethanol - dialysis - & fomepizole

16. What is the category of drug names ending in - cycline (e.g. Tetracycline)
Antibiotic - protein synthesis inhibitor.
- Corticosteroids - heparin
- Acetaldehyde - Nausea - vomiting - headache - & hypotension
1. Peptic ulcer 2. Gastritis 3. Esophageal reflux 4. Zollinger - Ellison syndrome

17. Thiazides - site of action?
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.
decrease conduction velocity - increase ERP - increase PR interval
- N- acetylcystine
distal convoluted tubule (early)

18. What is the clinical use for Warfarin?
Chronic anticoagulation.
Chronic Hepatitis A and B - Kaposi's Sarcoma
The PTT.
Paranteral (IV - SC)

19. List the specific antidote for this toxin: Lead
- MT polymerization stabilizer - Ovarian & breast CA - Myelosupperession & hypersensitivity.
cortical collecting tubule
- EDTA - dimercaprol - succimer - & penicillamine
Similar to cyclosporine; binds to FK- binding protein - inhibiting secretion of IL-2 and other cytokines.

20. What are three complications of Warfarin usage?
1. Bleeding 2. Teratogenicity 3. Drug - drug interactions
Beta 2 agonist; desired effect is the relaxation of bronchial smooth muscle (Beta 2). Use during acute exacerbation.
- Sulfonamides - furosemide - methicillin - rifampin - NSAIDS (ex. ASA)
Cephalosporins

21. What conditions would you use dantrolene?
1. Streptokinase 2. Urokinase 3. tPA (alteplase) - APSAC (anistreplase)
severe orthostatic hypotension - blurred vision - constipation - sexual dysfunction
1. Heavy bleeding 2. GI effects (n/v - anorexia) 3. Abdominal pain
In treatment of malignant hyperthermia - due to concomitant use of halothane and succinylcholine. Also in neuroleptic malignant syndrome - a toxicity of antipsychotic drugs.

22. What is the category and mechanism of action of Zafirlukast in Asthma treatment?
for RSV
GI intolerance (nausea - diarrhea) - Hyperglycemia - Lipid abnormalities - Thrombocytopenia (Indinavir)
- Triggers apoptosis - CLL - Hodgkin's in MOPP - Cushing - like syndrome
Antileukotriene; blocks leukotriene receptors.

23. How is Vancomycin used clinically?
Early myocardial infarction.
For serious - Gram + multidrug - resistant organisms
Inhibits platelet aggregation by irreversibly inhibiting the ADP pathway involved in the binding of fibrinogen.
depresses ectopic pacemakers - especially in digoxin toxicity

24. What is the formula for Clearance (CL)
1. Pioglitazone 2. Rosiglitazone.
Antiprotozoal: Giardia - Entamoeba - Trichomonas - Gardnerella vaginalis Anaerobes: Bacteroides - Clostridium
- Phase I (clinical tests) - Phase II - Phase III - PhaseIV (surveillance)
CL= (rate of elimination of drug/ Plasma drug conc.)

25. Ca2+ channel blockers - site of action?
Antifungal.
- Shifts the curve to the right - increases Km
- Ethosuxamide - sulfonamides - lamotrigine
Cell membrane Ca2+ channels of cardiac sarcomere

26. Describe the MOA of Interferons (INF)
- Niacin - Ca++ channel blockers - adenosine - vancomycin
Choline acetyltransferase
Increases mean - systolic - and diastolic bp - while there is little change in pulse pressure.
Glycoproteins from leukocytes that block various stages of viral RNA and DNA synthesis

27. Antiarrhythmic class II- effects?
1. Meningococcal carrier state 2. Chemoprophylaxis in contacts of children with H. influenzae type B
Hemolysis (if G6PD deficient) - Neurotoxicity - Hepatotoxicity - SLE- like syndrome
decrease the slope of phase 4 - increase PR interval (the AV node is particularly sensitive)
Yes - it does not cross the placenta.

28. The MOA for Chloramphenicol is?
Nephrotoxicity
Inhibition of 50S peptidyl transferase - Bacteriostatic
Increased systolic and pulse pressure - decreased diastolic pressure - and little change in mean pressure.
Centrally acting alpha agonist - thus causing a decrease in central adrenergic outflow - spairing renal blood flow

29. What is the category - desired effect - and adverse effect of Isoproterenol in the treatment of Asthma?
is resistant
Pseudomonas species and Gram - rods
Nonspecific beta - agonist; desired effect is the relaxation of bronchial smooth muscle (Beta 2). Adverse effect is tachycardia (Beta 1).
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.

30. Procainamide - toxicity?
Digitoxin 168hrs Digoxin 40 hrs
reversible SLE- like syndrome
torsade de pointes - excessive Beta block
dizziness - flushing - constipation (verapamil) - nausea

31. Mg+- clinical use?
Bleeding.
No
effective in torsade de pointes and digoxin toxicity
Prophylaxis for Influenza A - Rubella; Parkinson's disease

32. What is the mechanism of action and clinical use of the antiandrogens Ketoconazole and Spironolactone?
Ipratropium
viral kinase
Inhibit steroid synthesis - used in the treatment of polycystic ovarian syndrome to prevent hirsutism.
1. Addison's disease 2. Inflammation 3. Immune suppression 4. Asthma

33. List the specific antidote for this toxin: Opioids
1. Significant: nephrotoxicity 2. Peripheral neuropathy 3. Hypertension 4. Pleural effusion 5. Hyperglycemia.
Keratin containing tissues - e.g. - nails
- Constant AMOUNT eliminated per unit time. - Etoh & ASA
- B51Naloxone / naltrexone (Narcan)

34. 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
Aminoglycosides
Dopamine
Botulinum
Gram + cocci - Gram - rods - and Anerobes

35. Which receptors does phenylephrine act upon?
TCA
alpha -1 > alpha -2; used as a pupil dilator - vasoconstrictor - and for nasal decongestion
No - it inhibits the release of Nor Epi
1. Pioglitazone 2. Rosiglitazone.

36. What is the clinical use of Tacrolimus (FK506)?
fetal renal toxicity - hyperkalemia
Potent immunosuppressive used in organ transplant recipients.
Inhibits reabsorption of uric acid.
Inhibits Viral DNA polymerase

37. What are are the Sulfonylureas (general description) and What is their use?
Yes
Cilastatin
Spironolactone - Triamterene - Amiloride (the K+ STAys)
Sulfonylureas are oral hypoglycemic agents - they are used to stimulate release of endogenous insulin in NIDDM (type -2).

38. What is Fluconazole specifically used for?
Cryptococcal meningitis in AIDS patients and Candidal infections of all types
Penicillin - Cephalosporins - Vancomycin - Aminoglycosides - Fluoroquinolones - Metronidazole
Systemic mycoses
Interferes with microtubule function - disrupts mitosis - inhibits growth

39. What is the receptor affinity and clinical use of isoproterenol?
1. Hot flashes 2. Ovarian enlargement 3. Multiple simultaneous pregnancies 4. Visual disturbances
Sotalol - Ibutilide - Bretylium - Amiodarone
It affects beta receptors equally and is used in AV heart block (rare).
Protamine Sulfate is used for rapid reversal of heparinization (positively charged molecule that binds to negatively charged heparin).

40. Which RT inhibitors cause Lactic Acidosis?
Nucleosides
AluMINIMUM amount of feces.
RESPIre
Intrathecally

41. Name several common Macrolides (3)
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.)
Altered bacterial Dihydropteroate Synthetase - Decreased uptake - or Increased PABA synthesis
Vibrio cholerae Acne Chlamydia Ureaplasma Urealyticum Mycoplasma pneumoniae Borrelia burgdorferi (Lyme's) Rickettsia Tularemia
Erythromycin - Azithromycin - Clarithromycin

42. How does a noncompetitive antagonist effect an agonist?
Oral
- Shifts the curve down - reduces Vmax
Penicillin - Ampicillin - Ticarcillin - Pipercillin - Imipenem - Aztreonam - Cephalosporins
1. RNA pol inhibitor 2. Revs up P450 3. Red/orange body fluids 4. Rapid resistance if used alone

43. What is the MOA of Ganciclovir?
Severe Gram - rod infections.
ACIDazolamide' causes acidosis
Inhibits CMV DNA polymerase
Mg = Must go to the bathroom.

44. Which drug(s) cause this reaction: Atropine - like side effects?
- Tricyclic antidepressants
- B51Naloxone / naltrexone (Narcan)
Protamine Sulfate is used for rapid reversal of heparinization (positively charged molecule that binds to negatively charged heparin).
AV nodal cells

45. What is the mechanism of action of Cyclosporine?
Binds to cyclophilins (peptidyl proline cis - trans isomerase) - blocking the differentiation and activation of T cells mainly by inhibiting the production of IL-2 and its receptor.
hypertension - angina - arrhythmias
Reversibly inhibits cyclooxygenase - mostly in CNS. Inactivated peripherally.
Nephrotoxicity (esp. with Cephalosporins) - Ototoxicity (esp. with Loop Diuretics)

46. What cholinergic inhibitor acts by directly inhibiting Ach release at the presynaptic terminal
Minor hepatotoxicity - Drug interactions (activates P450)
Botulinum
Epinephrine
Lovastatin - Pravastatin - Simvastatin - Atorvastatin

47. Which drug(s) cause this reaction: Pulmonary fibrosis(3)?
- Bleomycin - amiodarone - busulfan
edematous states (CHF - cirrhosis - nephrotic syndrome - pulm edema) - HTN - hypercalcemia
Aminoglycosides
- Tricyclic antidepressants

48. Aztreonam is not usually...
toxic
physostigmine
Malaria (P. falciparum)
Because they require some residual islet function.

49. Which drug increases Sys BP w/o affecting Pulse Pressure
Inhibits organification and coupling of thyroid hormone synthesis. Also decreases peripheral conversion of T4 to T3.
GI disturbances.
Epinephrine
Prophylaxis for Influenza A - Rubella; Parkinson's disease

50. What is the clinical use for Ampicillin and Amoxicillin?
GI discomfort - Acute cholestatic hepatitis - Eosinophilia - Skin rashes
Non - Nucleosides
1. Tolbutamide 2. Chlorpropamide 3. Glyburide 4. Glipizide
Extended spectrum penicillin: certain Gram + bacteria and Gram - rods