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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. What is Ketoconazole specifically used for?
toxic
Penicillin - Ampicillin - Ticarcillin - Pipercillin - Imipenem - Aztreonam - Cephalosporins
Albuterol - tertbutaline
Blastomyces - Coccidioides - Histoplasma - C. albicans; Hypercortisolism

2. For Heparin What is the Route of administration
1) Aminoglycosides = bactericidal 2) Tetracyclines = bacteriostatic
all of them
Paranteral (IV - SC)
sedation - depression - nasal stuffiness - diarrhea

3. Ethacrynic Acid - clinical use?
Diuresis in pateints with sulfa allergy
Minor hepatotoxicity - Drug interactions (activates P450)
AZT - to reduce risk of Fetal Transmission
Acetylates and irreversibly inhibits cyclooxygenase (COX I and COX II) to prevent the conversion of arachidonic acid to prostaglandins.

4. What is the mechanism of action of Sildenafil (Viagra)?
Receptors = D1=D2>beta>alpha - thus increasing heart rate (beta) and blood pressure (alpha vasoconstriction) while maintaining kidney perfusion (dopamine receptors)
Erythromycin - Azithromycin - Clarithromycin
Inhibits cGMP phosphodiesterase - casuing increased cGMP - smooth muscle relaxation in the corpus cavernosum - increased blood flow - and penile erection.
Small lipid - soluble molecule

5. Toxicities associated with Acyclovir?
Polymyxin B - Polymyxin E
hypertrichosis - pericardial effusion - reflex tachycardia - angina - salt retention
Reversible block of histamine H2 receptors
Delirium - Tremor - Nephrotoxicity

6. As an Anes you want to use a depolarizing neuromuscular blocking drug on your pt - What do you use
fetal renal toxicity - hyperkalemia
proarrhythmic
Similar to cyclosporine; binds to FK- binding protein - inhibiting secretion of IL-2 and other cytokines.
Succinylcholine

7. Adverse effects of Nifedipine - verapamil?
- Hydralazine - Procainamide - INH - phenytoin
dizziness - flushing - constipation (verapamil) - nausea
1. Aluminum hydroxide: constipation and hypophosphatemia 2. Magnesium hydroxide: diarrhea 3. Calcium carbonate: Hypercalcemia - rebound acid increase - All may cause hypokalemia
Protamine Sulfate is used for rapid reversal of heparinization (positively charged molecule that binds to negatively charged heparin).

8. Antiarrhythmic class IV- primary site of action?
Ibuprofen - Naproxen - and Indomethacin
AV nodal cells
Irreversibly inhibits H+/K+ ATPase in stomach parietal cells.
Penicillin - V

9. Procainamide - toxicity?
- Alkalating agent - testicular - bladder - ovary -& lung - Nephrotoxicity & CN VIII damage.
reversible SLE- like syndrome
- Physostigmine salicylate
Hemolysis (if G6PD deficient) - Neurotoxicity - Hepatotoxicity - SLE- like syndrome

10. Why is pyridostigmine effective in the treatment of myasthenia gravis?
As an anticholinesterase it increases endogenous ACh and thus increases strength.
- Hydralazine - Procainamide - INH - phenytoin
These B-2 agonists cause respiratory smooth muscle to relax.
When pts have Low CD4+ (< 500 cells/cubic mm) or a High Viral Load

11. List the specific antidote for this toxin: Arsenic (all heavy metals)
Alpha -1 antagonist
Captopril - Enalapril - Lisinopril
- Dimercaprol - succimer
Ipratropium

12. What cholinergic inhibitor acts by directly inhibiting Ach release at the presynaptic terminal
Heparin catalyzes the activation of antithrombin III.
Staphlococcus aureus and Clostridium difficile (pseudomembranous colitis)
AZT - to reduce risk of Fetal Transmission
Botulinum

13. How is Ganciclovir activated?
Suramin
Phosphorylation by a Viral Kinase
edrophonium (extremely short acting anticholinesterase)
Gram + - Gram - - Norcardia - Chlamydia

14. Adenosine - clinical use?
DOC in diagnosing and abolishing AV nodal arrhythmias
all except the K+ sparing diuretics Spironolactone - Triamterene - Amiloride
Benzathine penicillin G
Choline acetyltransferase

15. Which drug(s) cause this reaction: Disulfram - like reaction (4) ?
glaucoma - urinary alkalinization - metabolic alkalosis - altitude sickness
DHPG (dihydroxy-2- propoxymethyl guanine)
Penicillin - Ampicillin - Ticarcillin - Pipercillin - Imipenem - Aztreonam - Cephalosporins
- Metronidazole - certain cephalosporins - procarbazine - sulfonylureas

16. What is the major side effect for Carbenicillin - Piperacillin - and Ticarcillin?
Dermatophytes (tinea - ringworm)
Onchocerciasis ('river blindness'-- rIVER- mectin)
hypertrichosis - pericardial effusion - reflex tachycardia - angina - salt retention
Hypersensitivity reactions

17. What is the category of drug names ending in - azepam (e.g. Diazepam)
Benzodiazepine.
Receptors = D1=D2>beta>alpha - thus increasing heart rate (beta) and blood pressure (alpha vasoconstriction) while maintaining kidney perfusion (dopamine receptors)
Inhibt Assembly of new virus by Blocking Protease Enzyme
- Bleomycin - amiodarone - busulfan

18. What is the effect of the Glitazones in diabetes treatment?
collecting ducts
Increase target cell response to insulin.
Fast vs. Slow Acetylators
1. Reliable (<1% failure) 2. Lowers risk of endometrial and ovarian cancer 3. Decreased incidence of ectopic pregnancy 4. Lower risk of pelvic infections 5. Regulation of menses

19. What is the mechanism of action of the glucocorticoids?
Decrease the production of leukotrienes and protaglandins by inhibiting phospholipase A2 and expression of COX-2.
None. No - because atropine would block the postganglionic muscarinic receptors involved in sweat gland stimulation.
hyperkalemia - endocrine effects (gynecomastia - anti - androgen)
- ED 50 is less than the Km (less than 50% of receptors)

20. What antimuscarinic drug is useful for the tx of asthma
Dopamine; causes its release from intact nerve terminals
HTN - CHF - calcium stone formation - nephrogenic DI.
proarrhythmic
Ipratropium

21. List the specific antidote for this toxin: Carbon monoxide
-100% oxygen - hyperbaric
Prevents the release of ACh - Which results in muscle paralysis.
Atropine would also block the receptors in the ciliary muscle - causing an impairment in accommodation (cycloplegia).
- Methotrexate - 5 FU - 6 mercaptopurine

22. Which drug(s) cause this reaction: Aplastic anemia (5)?
Sucralfate cannot work in the presence of antacids or H2 blockers because it requires an acidic environment to polymerize.
- Chloramphenicol - benzene - NSAIDS - PTU - phenytoin
osmotic diuretic - increase tubular fluid osmolarity - thereby increasing urine flow
GI discomfort - Acute cholestatic hepatitis - Eosinophilia - Skin rashes

23. For Heparin What is the Onset of action
Rapid (seconds)
Nephrotoxicity (esp. with Cephalosporins) - Ototoxicity (esp. with Loop Diuretics)
No
Hemicholinium inhibits the transport of choline into the nerve - thus inhibiting formation of ACh.

24. What is the category of drug names ending in - terol (e.g. Albuterol)
Beta lactams - inhibit cell wall synthesis - Bactericidal
viral kinase
- Constant AMOUNT eliminated per unit time. - Etoh & ASA
Beta -2 agonist.

25. What is a common side effect of Misoprostol?
Teratogenic - Carcinogenic - Confusion - Headaches
Chronic Hepatitis A and B - Kaposi's Sarcoma
Diarrhea
Hemolysis (if G6PD deficient) - Neurotoxicity - Hepatotoxicity - SLE- like syndrome

26. What is the mecanism of action of Sucralfate?
anticholinesterase glaucoma
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.
Tubocurarine - atracurium - mivacurium - pancuronium - vecuronium - rapacuronium
1. Tolbutamide 2. Chlorpropamide 3. Glyburide 4. Glipizide

27. Beta Blockers - CV toxicity?
Phenothiazine (neuroleptic - antiemetic).
Acetylates and irreversibly inhibits cyclooxygenase (COX I and COX II) to prevent the conversion of arachidonic acid to prostaglandins.
bradycardia - AV block - CHF
Diuresis in pateints with sulfa allergy

28. Ca2+ channel blockers - mechanism?
block voltage dependent L- type Ca2+ channels of cardiac and smooth muscle - decreasing contractility
Inhibits NaCl reabsorption in the early distal tubule. Decreases Ca2+ excretion.
Polymyxins
Depolymerizes microtubules - impairing leukocyte chemotaxis and degranulation.

29. What is the MOA for the Cephalosporins?
Beta lactams - inhibit cell wall synthesis - Bactericidal
Antiprotozoal: Giardia - Entamoeba - Trichomonas - Gardnerella vaginalis Anaerobes: Bacteroides - Clostridium
Binds ergosterol - Disrupts fungal membranes
NE acts presynaptically on alpha -2 receptors to inhibit its own release. ACh also acts presynaptically through M1 receptors to inhibit NE release.

30. What beta 2 agonist will help your 21yo Astma pt?
Bind cell membrane - disrupt osmotic properties - Are Cationc - Basic and act as detergents
- Alkalating agent - testicular - bladder - ovary -& lung - Nephrotoxicity & CN VIII damage.
for RSV
Albuterol - tertbutaline

31. Which drug(s) cause this reaction: Hepatitis?
- Isoniazid
Pseudomembranous colitis (C. difficile) - fever - diarrhea
No. Atropine is used to reduce urgency in mild cystitis. So it would aggravate the urinary retention.
Abortifacient.

32. List the specific antidote for this toxin: Digitalis
all except the K+ sparing diuretics Spironolactone - Triamterene - Amiloride
Beta Blockers
- Normalize K+ - Lidocaine - & Anti - dig Mab
Ganciclovir is more toxic to host enzymes

33. Which drug(s) cause this reaction: Extrapyramidal side effects (3)?
Penicillin - V
Gram + cocci - Haemophilus influenza - Enterobacter aerogenes - Neisseria species - P. mirabilis - E. coli - K. pneumoniae - Serratia marcescens ( HEN PEcKS )
- Chlorpromazine - thioridazine - haloperidol
fetal renal toxicity - hyperkalemia - Cough - Angioedema - Proteinuria - Taste changes - hypOtension - Pregnancy problems - Rash - Increased renin - Lower Angiotensin II (CAPTOPRIL)

34. Clinical use of Isoniazid (INH)?
- Protamine
Mycobacterium tuberculosis - the only agent used as solo prophylaxis against TB
Ipratropium
Acute coronary syndrome; coronary stenting. Decreases the incidence or recurrence of thrombotic stroke.

35. Antiarrhythmic class IB- clinical uses?
- ED 50 is less than the Km (less than 50% of receptors)
post MI and digitalis induced arrhythmias
Prophylaxis for Influenza A - Rubella; Parkinson's disease
block voltage dependent L- type Ca2+ channels of cardiac and smooth muscle - decreasing contractility

36. Secretion of What drug is inhibited by Probenacid used to treat chronic gout?
Competitive inibitor of progestins at progesterone receptors.
Parkinson patients benefit from antimuscarinic agents through its inhibitory action within the indirect pathway.
- Airway - Breathing - Circulation - Dextrose (thiamine & narcan) - ABCD
Penicillin.

37. Bretyllium - toxicity?
IV vitamin K and fresh frozen plasma
- partial agonist can have increased - decreased - /A21or equal potency as full agonist. - Potency is an independent factor.
Inhibits Viral DNA polymerase
new arrhythmias - hypotension

38. What should not be taken with Tetracyclines? / Why?
distal convoluted tubule (early)
Sildenafil fills the penis
Diuresis in pateints with sulfa allergy
Milk or Antacids - because divalent cations inhibit Tetracycline absorption in the gut

39. MOA of Succinylcholine
- Infections - Trauma - Seizures - CO - Overdose - Metabolic - Alcohol (IT'S COMA)
Peptic ulcer disease.
Cardiac glycoside (inotropic agent).
Prevents the release of Ca from SR of skeletal muscle

40. What do Aminoglycosides require for uptake?
Gemfibrozil - Clofibrate
As PABA antimetabolites that inhibit Dihydropteroate Synthase - Bacteriostatic
- Tamoxifen
Oxygen

41. For Warfarin What is the Lab value to monitor
GI intolerance (nausea - diarrhea) - Hyperglycemia - Lipid abnormalities - Thrombocytopenia (Indinavir)
Indomethacin is used to close a patent ductus arteriosus.
- B51Naloxone / naltrexone (Narcan)
PT

42. What are three complications of Warfarin usage?
1. Bleeding 2. Teratogenicity 3. Drug - drug interactions
- Metronidazole - certain cephalosporins - procarbazine - sulfonylureas
1) Chloramphenical = bacteriostatic 2) Erythromycin = bacteriostatic 3) Lincomycin = bacteriostatic 4)cLindamycin = bacteriostatic
Aminoglycosides

43. What is the MOA for the Macrolides?
Pseudomonas species and Gram - rods
Blocks translocation - binds to the 23S rRNA of the 50S subunit - Bacteriostatic
Beta lactams - inhibit cell wall synthesis - Bactericidal
cyanide toxicity (releases CN)

44. Which drug(s) cause this reaction: Stevens - Johnson syn. (3)?
Chronic Hepatitis A and B - Kaposi's Sarcoma
- Class III antiarrhythmics (sotalol) - class IA (quinidine)
Primaquine
- Ethosuxamide - sulfonamides - lamotrigine

45. MOA: Block protein synthesis at 30s subunit
Aminoglycosides - Tetracyclines
cholestyramine - colestipol
Prevents the release of Ca from SR of skeletal muscle
It acts presynaptically to increase NE release.

46. Furosemide - toxicity? (OH DANG)
Gram + and Anerobes
It acts presynaptically to increase NE release.
Ototoxicity - Hypokalemia - Dehydration - Allergy (sulfa) - Nephritis (interstitial) - Gout
With an amino acid change of D- ala D- ala to D- ala D- lac

47. Which Tetracycline is used in patients with renal failure? / Why?
Those patients who are taking nitrates.
- Phenytoin
Theoretically it could be used to block the cephalic phase of acid secretion (vagal stimulation).
Doxycycline - because it is fecally eliminated

48. Dobutamine used for the tx of shock acts on Which receptors
Beta1 more than B2
- Halothane - Valproic acid - acetaminophen - Amantia phalloides
Praziquantel
No. Atropine is used to reduce urgency in mild cystitis. So it would aggravate the urinary retention.

49. List the mechanism - clinical use - & toxicity of Busulfan.
- Alkalates DNA - CML - Pulmonary fibrosis hyperpigmentation
Gram + - Gram - - Norcardia - Chlamydia
compensatory tachycardia - fluid retention - lupus - like syndrome
- DNA intercalator - testicular & lymphomas - Pulmonary fibrosis mild myelosuppression.

50. Digoxin v. Digitoxin: excretion?
Digoxin=urinary Digitoxin=biliary
Atropine pts are suffering from Cholinestrase inhibitor poisining (Nerve gas/Organophosphate poisining)
- Alkalate DNA - Brain tumors - CNS toxicity
toxic