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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. For Warfarin What is the Lab value to monitor
Those patients who are taking nitrates.
Acts as a wide spectrum carbapenem
Hypersensitivity reactions
PT

2. What is the category of drug names ending in - operidol (e.g. Haloperidol)
TMP- SMZ
Butyrophenone (neuroleptic).
Rash - Pseudomembranous colitis
- Act on same receptor - Full has greater efficacy

3. Resistance mechanisms for Vancomycin
ACE inhibitor.
fetal renal toxicity - hyperkalemia
first dose orthostatic hypotension - dizziness - headache
Terminal D- ala of cell wall replaced with D- lac; Decreased affinity

4. What additional side effects exist for Ampicillin?
1. Bleeding 2. Thrombocytopenia 3. Drug - drug interactions
Penicillin - G
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.
Rash - Pseudomembranous colitis

5. What parasitic condition is treated with Ivermectin?

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6. What are the phases of succinylcholine neuromuscular blockade?
Phase 1 = prolonged depolarization - no antidote - effect potentiated by anticholinesterase; Phase 2 = repolarized but blocked - an anticholinesterase is the antidote for this phase.
- acetylation - glucuron. - & sulfation - Conjugation - Polar product
alpha -1 > alpha -2; used as a pupil dilator - vasoconstrictor - and for nasal decongestion
Chagas' disease - American Trypanosomiasis (Trypanosoma cruzi)

7. Ibutilide - toxicity?
It would increase to ~ 100 beats/min. Both sympathetic and vagal stimulation would be knocked out - but the SA node has an intrinsic pace of 100 beats/min - Which is normally checked by vagal stimulation.
torsade de pointes
- Haloperidol - chlorpromazine - reserpine - MPTP
is resistant

8. What drug is used during the pregnancy of an HIV+ mother? - Why?
- reduction - oxy - & hydrolysis - H2O sol. Polar product - P450
- Haloperidol - chlorpromazine - reserpine - MPTP
AZT - to reduce risk of Fetal Transmission
Meningitis (H. influenza - N. meningitidis - S. pneumoniae) - Conserative treatment due to toxicities

9. What is the MOA for the Fluoroquinolones?
1) Aminoglycosides = bactericidal 2) Tetracyclines = bacteriostatic
Blastomyces - Coccidioides - Histoplasma - C. albicans; Hypercortisolism
Inhibit DNA Gyrase (topoisomerase II) - Bactericidal
Erectile dysfunction.

10. What is the MOA for the Aminoglycosides?
Inhibits formation of Initiation Complex - causes misreading of mRNA - Bactericidal
- Glucagon
1. Heavy bleeding 2. GI effects (n/v - anorexia) 3. Abdominal pain
Beta 2 agonist; used as a long - acting agent for prophylaxis. Adverse effects are tremor and arrhythmia.

11. Antiarrhythmic class IV- effects?
sedation - sleep alterations
CMV - esp in Immunocompromised patients
- Quinidine - quinine
decrease conduction velocity - increase ERP - increase PR interval

12. What is the mechanism of action of the thrombolytics?
Hemolysis (if G6PD deficient) - Neurotoxicity - Hepatotoxicity - SLE- like syndrome
Inhibit RT of HIV and prevent the incorporation of viral genome into the host DNA
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.)
Inhibit intestinal bursh border Alpha - glucosidases; delayed hydrolysis of sugars and absorption of sugars leading to decresed postprandial hyperglycemia.

13. What is the mechanism of action of the glucocorticoids?
anticholinesterase glaucoma
- Protamine
Decrease the production of leukotrienes and protaglandins by inhibiting phospholipase A2 and expression of COX-2.
- Alkalates DNA - CML - Pulmonary fibrosis hyperpigmentation

14. What enzyme is responsible for the production of Ach from Acetyl CoA and Choline
Chagas' disease - American Trypanosomiasis (Trypanosoma cruzi)
Leukotrienes increasing bronchial tone.
Choline acetyltransferase
Nitrates

15. Are not penicillinase resistant
Increases coumadin metabolism
- Deferoxamine
constipation - flushing - edema - CV effects (CHF - AV block - sinus node depression) - and torsade de pointes (Bepridil)
Carbenicillin - Piperacillin - and Ticarcillin

16. Which drug(s) cause this reaction: Gynecomastia (6)?
viral kinase
Vd= (Amt. of drug in body/ Plasma drug conc.)
Oral
- Cimetidine - ketoconazole - spironolactone - digitalis - EtOH - estrogens

17. The MOA for Chloramphenicol is?
Vibrio cholerae Acne Chlamydia Ureaplasma Urealyticum Mycoplasma pneumoniae Borrelia burgdorferi (Lyme's) Rickettsia Tularemia
Peptic ulcer disease.
Beta lactams - inhibit cell wall synthesis - Bactericidal
Inhibition of 50S peptidyl transferase - Bacteriostatic

18. What are two Glitazones?
No - hemicholinum block the uptake of Choline and thus Ach synthesis
1. Pioglitazone 2. Rosiglitazone.
NO
viral kinase

19. Which drug(s) cause this reaction: Gray baby syndrome?
Captopril - Enalapril - Lisinopril
- Chloramphenicol
- Methylene blue
Beta 2 agonist; desired effect is the relaxation of bronchial smooth muscle (Beta 2). Use during acute exacerbation.

20. What are the clinical uses for 1st Generation Cephalosporins?
Acute gout.
As an anticholinesterase it increases endogenous ACh and thus increases strength.
Gram + cocci - Proteus mirabilis - E. coli - Klebsiella pneumoniae (PEcK)
HTN - CHF - calcium stone formation - nephrogenic DI.

21. Which drug(s) cause this reaction: Hepatitis?
distal convoluted tubule (early)
Inhibits bacterial Dihydrofolate Reductase - Bacteriostatic
- Isoniazid
new arrhythmias - hypotension

22. List the specific antidote for this toxin: Salicylates
Sulfamethoxazole (SMZ) - Sulfisoxazole - Triple sulfas - Sulfadiazine
dizziness - flushing - constipation (verapamil) - nausea
- Alkalinize urine & dialysis
- Penicillamine

23. Acetazolamide - clinical uses?
glaucoma - urinary alkalinization - metabolic alkalosis - altitude sickness
Giant Roundworm (Ascaris) - Hookworm (Necator/Ancylostoma) - Pinworm (Enterobius)
- ACE inhibitors (Losartan>no cough)
Similar to cyclosporine; binds to FK- binding protein - inhibiting secretion of IL-2 and other cytokines.

24. How is Amphotericin B used clinically?
Acute coronary syndrome; coronary stenting. Decreases the incidence or recurrence of thrombotic stroke.
first dose orthostatic hypotension - dizziness - headache
Wide spectrum of systemic mycoses: Cryptococcus - Blastomyces - Coccidioides - Aspergillus - Histoplasma - Candida - Mucor
As an anticholinesterase it increases endogenous ACh and thus increases strength.

25. List the mechanism - clinical use - & toxicity of Tamoxifen.
carbonic anhydrase inhibitors - K+ sparing diuretics
Penicillin - G
- Upper respiratory tract infections - pneumonias - STDs: Gram+ cocci (streptococcal infect in pts allergic to penicillin) - Mycoplasma - Legionella - Chlamydia - Neisseria
- Estrogen receptor antagonist - Breast CA - increased endometrial CA risk

26. What is a common side effect of Colchicine used to treat acute gout - especially When given orally?
Because they require some residual islet function.
Large anionic polymer - acidic
GI side effects. (Indomethacin is less toxic - more commonly used.)
Gram - rods: Klebsiella species - Pseudomonas species - Serratia species

27. List the specific antidote for this toxin: Methanol & Ethylene glycol
- Ethanol - dialysis - & fomepizole
very short acting
Acute (hours)
Methicillin - Nafcillin - and Dicloxacillin

28. List the mechanism - clinical use - & toxicity of Cyclophosphamide.
Prevents the release of ACh - Which results in muscle paralysis.
Cardiac glycoside (inotropic agent).
- Alkalating agent - NHL - Breast - ovary - & lung. - Myelosuppression - & hemorrhagic cystitis.
Give an antichloinesterase - neostigmine - edrophonium - etc

29. MOA for Penicillin (3 answers)?
Gram + cocci - Gram - rods - and Anerobes
1)Binds penicillin - binding proteins 2) Blocks transpeptidase cross - linking of cell wall 3) Activates autolytic enzymes
Acetylcholine esterase
1. Renal damage 2. Aplastic anemia 3. GI distress

30. List five common glucocorticoids.
torsade de pointes - excessive Beta block
-100% oxygen - hyperbaric
1. Hydrocortisone 2. Predisone 3. Triamcinolone 4. Dexamethasone 5. Beclomethasone
AluMINIMUM amount of feces.

31. Which drug(s) cause this reaction: Gingival hyperplasia?
Buy AT 30 - CELL at 50'
Saquinavir - Ritonavir - Indinavir - Nelfinavir
- Phenytoin
1. Antiandrogen 2. Nausea 3. Vomiting

32. Adverse effects of Guanethidine?
orthostatic and exercise hypotension - sexual dysfunction - diarrhea
Chloramphenicol - Erythromycin/macrolides - Lincomycin - Clindamycin - Streptogramins (quinupristin - dalfopristin)
1. Mycobacterium tuberculosis 2. Delays resistance to Dapsone When used of Leprosy 3. Used in combination with other drugs
for RSV

33. Resistance mechanisms for Macrolides

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34. Ca2+ sensitizers'- site of action?
Aminoglycosides
troponin - tropomyosin system
decrease AP duration - affects ischemic or depolarized Purkinje and ventricular system
Post - op and neurogenic ileus and urinary retention - myasthenia gravis - and reversal of neuromuscular junction blockade (post - op) through anticholinesterase activity.

35. Adenosine - clinical use?
Inhibt Assembly of new virus by Blocking Protease Enzyme
-100% oxygen - hyperbaric
1. Antiandrogen 2. Nausea 3. Vomiting
DOC in diagnosing and abolishing AV nodal arrhythmias

36. Foscarnet does not require activation by a...
viral kinase
increased AP duration - increased ERP increased QT interval. Atrial and ventricular.
Blocks Norepi - but not Dopamine
- Estrogen receptor antagonist - Breast CA - increased endometrial CA risk

37. Mannitol - clinical use?
ARF - shock - drug overdose - decrease intracranial/intraocular pressure
Inhibition of 50S peptidyl transferase - Bacteriostatic
Delirium - Tremor - Nephrotoxicity
1. Bleeding 2. Teratogenicity 3. Drug - drug interactions

38. Why would you use pralidoxime after exposure to an organophosphate?
Pralidoxime regenerates active cholinesterase.
Increases mean - systolic - and diastolic bp - while there is little change in pulse pressure.
Pyridoxine (B6) administration
dry mouth - sedation - severe rebound hypertension

39. Cocaine casues vasoconstriction and local anesthesia by What mechanism
Beta - lactamase cleavage of Beta - lactam ring
Indirect agonist - uptake inhibitor
new arrhythmias - hypotension
Small lipid - soluble molecule

40. What are the four conditions in Which Omeprazole - Lansoprazole is used?
1. Peptic ulcer 2. Gastritis 3. Esophageal reflux 4. Zollinger - Ellison syndrome
Blood
1. Phospholipase A2 is prevented from releasing arachidonic acid 2. Decreases protein synthesis thus lowering amount of Cyclooxygenase enzymes
- Sulfonamides - INH - ASA - Ibuprofen - primaquine - nitrofurantoin /- pyrimethamine - chloramphenicol

41. If a patient is given hexamethonium - What would happen to his/her heart rate?
Antiprotozoal: Giardia - Entamoeba - Trichomonas - Gardnerella vaginalis Anaerobes: Bacteroides - Clostridium
- Triggers apoptosis - CLL - Hodgkin's in MOPP - Cushing - like syndrome
- acetylation - glucuron. - & sulfation - Conjugation - Polar product
It would increase to ~ 100 beats/min. Both sympathetic and vagal stimulation would be knocked out - but the SA node has an intrinsic pace of 100 beats/min - Which is normally checked by vagal stimulation.

42. Acetazolamide - site of action?
proximal convoluted tubule
Inhibit DNA Gyrase (topoisomerase II) - Bactericidal
Lidocaine - Mexiletine - Tocainide
1. Heavy bleeding 2. GI effects (n/v - anorexia) 3. Abdominal pain

43. Which drug(s) cause this reaction: G6PD hemolysis(8)?
- Sulfonamides - INH - ASA - Ibuprofen - primaquine - nitrofurantoin /- pyrimethamine - chloramphenicol
Tubocurarine - atracurium - mivacurium - pancuronium - vecuronium - rapacuronium
Staphlococcus aureus
- Shifts the curve down - reduces Vmax

44. What effect would atropine have on a patient with peptic ulcer disease?
Theoretically it could be used to block the cephalic phase of acid secretion (vagal stimulation).
- Hypersensitivity reactions - Hemolysis - Nephrotoxicity (tubulointerstitial nephritis) - Kernicterus in infants Displace other drugs from albumin (e.g. - warfarin)
It inhibits release of NE.
The PTT.

45. What is the clincial use for Misoprostol?
Prevention of NSAID- induced peptic ulcers - maintains a PDA.
loop diuretics - thiazides
Decreases synthesis of Mycolic Acid
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.)

46. What are five toxicities associated with Tacrolimus (FK506)?
Erectile dysfunction.
- Protamine
1. Significant: nephrotoxicity 2. Peripheral neuropathy 3. Hypertension 4. Pleural effusion 5. Hyperglycemia.
Antileukotriene; blocks synthesis by lipoxygenase.

47. What is the definition of zero - order kinetics? Example?
- Constant AMOUNT eliminated per unit time. - Etoh & ASA
- Vinca alkaloids(inhibit MT) - Paclitaxel
H2 antagonist
reduce levels of Angiotensin II - thereby preventing the inactivation of bradykinin (a potent vasodilator); renin level is increased

48. What are three common NSAIDS other than Aspirin?
Intrathecally
nausea - headache - lupus - like syndrome - reflex tachycardia - angina - salt retention
Same as penicillin. Extended spectrum antibiotics
Ibuprofen - Naproxen - and Indomethacin

49. What is the category and mechanism of action of Zileuton in Asthma treatment?
Dopamine
Ceftriaxone
Antileukotriene; blocks synthesis by lipoxygenase.
diuretics - sympathoplegics - vasodilators - ACE inhibitors - Angiotensin II receptor inhibitors

50. How can Isoniazid (INH)- induced neurotoxicity be prevented?
Pyridoxine (B6) administration
Decrease the production of leukotrienes and protaglandins by inhibiting phospholipase A2 and expression of COX-2.
Blocks viral penetration/uncoating; may act to buffer the pH of the endosome
PT