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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. MOA: Bactericidal antibiotics
penicillinase resistant
Penicillin - Cephalosporins - Vancomycin - Aminoglycosides - Fluoroquinolones - Metronidazole
-100% oxygen - hyperbaric
Bactericidal for: Gram + rod and cocci - Gram - cocci - and Spirochetes

2. Why is carbachol and pilocarpine useful in treatment of glaucoma?
They activate the ciliary muscle of the eye (open angle) and pupillary sphincter (narrow angle).
Forms toxic metabolites in the bacterial cell - Bactericidal
carbonic anhydrase inhibitors - K+ sparing diuretics
Bactericidal for: Gram + rod and cocci - Gram - cocci - and Spirochetes

3. List the specific antidote for this toxin: Salicylates
- Alkalinize urine & dialysis
- Triggers apoptosis - CLL - Hodgkin's in MOPP - Cushing - like syndrome
cortical collecting tubule
Beta lactams - inhibit cell wall synthesis - Bactericidal

4. Hydralazine - clinical use?
Staphlococcus aureus and Clostridium difficile (pseudomembranous colitis)
severe hypertension - CHF
Ototoxicity - Hypokalemia - Dehydration - Allergy (sulfa) - Nephritis (interstitial) - Gout
- Clindamycin

5. Acetazolamide - site of action?
1. Hydrocortisone 2. Predisone 3. Triamcinolone 4. Dexamethasone 5. Beclomethasone
Pretreat with antihistamines and a slow infusion rate
Bacitracin - Vancomycin
proximal convoluted tubule

6. Which drug(s) cause this reaction: Neuro and Nephrotoxic?
Rifampin
- Tricyclic antidepressants
Acute (hours)
- polymyxins

7. What is the memory key for the effect of magnesium hydroxide overuse?
Prevents release of mediators from mast cells. Effective only for the prophylaxis of asthma. Not effective during an acute attack.
- Aminocaproic acid
Oxygen
Mg = Must go to the bathroom.

8. Antiarrhythmic Class III- effects?
Gentamicin - Neomycin - Amikacin - Tobramycin - Streptomycin
Succinylcholine
increase AP duration - increase ERP - increase QT interval - for use When other arrhythmics fail
Activates antithrombin III

9. What is Imipenem always administered with?
Cilastatin
Benzodiazepine.
Hydralazine and Minoxidil
decrease myocardial O2 consumption by: 1- decreasing end diastolic volume 2- decreasing BP 3- decreasing HR 4- decreasing contractility 5- decreasing ejection time

10. MOA: Block peptidoglycan synthesis
first dose orthostatic hypotension - dizziness - headache
Interferes with microtubule function - disrupts mitosis - inhibits growth
Bacitracin - Vancomycin
Tendonitis and Tendon rupture

11. What are nine findings of Iatrogenic Cushing's syndrome caused by glucocorticoid therapy?
decrease conduction velocity - increase ERP - increase PR interval
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
- Acetaldehyde - Nausea - vomiting - headache - & hypotension
1. Streptokinase 2. Urokinase 3. tPA (alteplase) - APSAC (anistreplase)

12. Which drug(s) cause this reaction: Drug induced Parkinson's (4) ?
GET on the Metro
Hypersensitivity reactions
- Haloperidol - chlorpromazine - reserpine - MPTP
Peptic ulcer disease.

13. Name some common Tetracyclines (4)
Digitoxin 70% Digoxin 20-40%
thiazides - amiloride
Nonspecific beta - agonist; desired effect is the relaxation of bronchial smooth muscle (Beta 2). Adverse effect is tachycardia (Beta 1).
Tetracycline - Doxycycline - Demeclocycline - Minocycline

14. Which drug(s) cause this reaction: Torsade de pointes (2)?
To inhibit renal Dihydropeptidase I and decrease Imipenem inactivation in the renal tubules
- Class III antiarrhythmics (sotalol) - class IA (quinidine)
Blood
Methylation of rRNA near Erythromycin's ribosome binding site

15. How does botulinum toxin result in respiratory arrest?
- Estrogen receptor antagonist - Breast CA - increased endometrial CA risk
- Methylene blue
- Penicillamine
Prevents the release of ACh - Which results in muscle paralysis.

16. Name two LPL stimulators.
Gemfibrozil - Clofibrate
Aplastic anemia (dose independent) - Gray Baby Syndrome
- Tricyclic antidepressants
Inhibt Assembly of new virus by Blocking Protease Enzyme

17. Secretion of What drug is inhibited by Probenacid used to treat chronic gout?
Neutropenia
Nitrates
Tetracycline - Doxycycline - Demeclocycline - Minocycline
Penicillin.

18. Adverse effects of ganglionic blockers?
- Chloramphenicol - benzene - NSAIDS - PTU - phenytoin
Decreases synthesis of Mycolic Acid
first dose orthostatic hypotension - dizziness - headache
severe orthostatic hypotension - blurred vision - constipation - sexual dysfunction

19. What is the category of drug names ending in - terol (e.g. Albuterol)
block voltage dependent L- type Ca2+ channels of cardiac and smooth muscle - decreasing contractility
Beta -2 agonist.
Disulfiram - like reaction with EtOH - Headache
Gram + and Anerobes

20. Aztreonam is not ________ with penicillins
Modification via Acetylation
- S- phase anti - metabolite folate analogue - Luk - Lymp - sarc - RA - & psoriasis / - Reversible myelosuppression
cross - allergenic
decrease myocardial O2 consumption by: 1- decreasing end diastolic volume 2- decreasing BP 3- decreasing HR 4- decreasing contractility 5- decreasing ejection time

21. Ethacrynic Acid - mechanism?
Yes
Chronic gout.
- Barbiturates - phenytoin - carbamazipine - rifampin - griseofulvin - quinidine
not a sulfonamide - but action is the same as furosemide

22. Which RT inhibitors cause Lactic Acidosis?
- Shifts the curve to the right - increases Km
Nucleosides
TMP- SMZ (DOC) - aerosolized pentamidine
1. Predisposes to viral infections and lymphoma 2. Nephrotoxic (preventable with mannitol diuresis)

23. Antimicrobial prophylaxis for Gonorrhea
Ceftriaxone
Benzathine penicillin G
Amphotericin B - Nystatin - Fluconazole/azoles
Inhibit intestinal bursh border Alpha - glucosidases; delayed hydrolysis of sugars and absorption of sugars leading to decresed postprandial hyperglycemia.

24. What is the mecanism of action of Sucralfate?
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.
cardiac depression - peripheral edema - flushing - dizziness - constipation
- Glucocorticoid withdrawal
Antileukotriene; blocks leukotriene receptors.

25. For Warfarin What is the Lab value to monitor
PT
Amphetamine and Ephedrine
Rifampin
1) Serious Gram - infections resistant to other Beta lactams 2) Meningitis (most penetrate the BBB)

26. What are toxicities associated with Chloramphenicol?
Edrophonium
Aplastic anemia (dose independent) - Gray Baby Syndrome
GI distress - Tooth discoloration and Inhibition of bone growth in children - Fanconi's syndrome - Photosensitivity
GnRH analog with agonist properties When used in pulsatile fashion and antagonist properties When used in continuous fashion - causing a transient initial burst of LH and FSH

27. Ganciclovir associated toxicities?
Leukopenia - Neutropenia - Thrombocytopenia - Renal toxicity
- Normalize K+ - Lidocaine - & Anti - dig Mab
cardiac depression - peripheral edema - flushing - dizziness - constipation
cross - allergenic

28. What enzyme is responsible for the breakdown of ACh in the synaptic cleft?
Acetylcholinesterase; ACh is broken down into choline and acetate.
Phenothiazine (neuroleptic - antiemetic).
1. Gastric ulceration 2. Bleeding 3. Hyperventilation 4. Reye's syndrome 5. Tinnitus (CN VIII)
HSV - VZV - EBV - Mucocutaneous and Genital Herpes Lesions - Prophylaxis in Immunocompromised pts

29. What is the category of drug names ending in - azine (e.g. Chlorpromazine)
Phenothiazine (neuroleptic - antiemetic).
- Sulfonamides - INH - ASA - Ibuprofen - primaquine - nitrofurantoin /- pyrimethamine - chloramphenicol
distal convoluted tubule (early)
Peptic ulcer disease.

30. Adverse effects of Hydralazine?
hyperkalemia - endocrine effects (gynecomastia - anti - androgen)
- Metronidazole - certain cephalosporins - procarbazine - sulfonylureas
nausea - headache - lupus - like syndrome - reflex tachycardia - angina - salt retention
Terminal D- ala of cell wall replaced with D- lac; Decreased affinity

31. Guanethidine enhances the release of Norepi?
No
AV nodal cells
No - it inhibits the release of Nor Epi
Reversibly inhibit cyclooxygenase (COX I and COX II). Block prostaglandin synthesis.

32. What are four conditions in Which H2 Blockers are used clinically?
Penicillin.
1. Peptic ulcer 2. Gastritis 3. Esophageal reflux 4. Zollinger - Ellison syndrome
Dermatophytes (tinea - ringworm)
Yes - it does not cross the placenta.

33. What musculo - skeletal side effects in Adults are associated with Floroquinolones?
AZT
Bleeding.
Tendonitis and Tendon rupture
Finasteride inhibits 5 Alpha - reductase - this decreases the conversion of testosterone to dihydrotestosterone - useful in BPH

34. What physiological effects was the Anes using Atropine to tx
Yes
- acetylation - glucuron. - & sulfation - Conjugation - Polar product
Misoprostol is a PGE1 analog that increases the production and secretion of the gastic mucous barrier.
SLUD (salivation - Lacrimation - urination - Defecation)as well as airway secretion - GI motility - acid secretions

35. Acetaldehyde is metabolized by Acetaldehyde dehydrogenase - Which drug inhibs this enzyme?
1. Heavy bleeding 2. GI effects (n/v - anorexia) 3. Abdominal pain
Staphlococcus aureus and Clostridium difficile (pseudomembranous colitis)
narcolepsy - obesity - and attention deficit disorder (I wouldn't recommend this)
- Disulfram & also sulfonylureas - metronidazole

36. How is Ribavirin used clinically?
Blocks translocation - binds to the 23S rRNA of the 50S subunit - Bacteriostatic
post MI and digitalis induced arrhythmias
for RSV
- Physostigmine salicylate

37. What is the category - desired effect - and period of use of albuterol in the treatment of Asthma?
- polymyxins
Protamine sulfate
Beta 2 agonist; desired effect is the relaxation of bronchial smooth muscle (Beta 2). Use during acute exacerbation.
1. Peptic ulcer 2. Gastritis 3. Esophageal reflux 4. Zollinger - Ellison syndrome

38. What antimuscarinic drug is useful for the tx of asthma
- Cimetidine - ketoconazole - spironolactone - digitalis - EtOH - estrogens
Ototoxicity - Hypokalemia - Dehydration - Allergy (sulfa) - Nephritis (interstitial) - Gout
Ipratropium
Warfarin interferes with the normal synthesis and gamma - carboxylation of vitamin K- dependent clotting factors II - VII - IX - and X - Protein C and S via vitamin K antagonism.

39. What is the MOA of the RT Inhibitors?
H2 antagonist
As an anticholinesterase it increases endogenous ACh and thus increases strength.
Inhibit RT of HIV and prevent the incorporation of viral genome into the host DNA
Stimulates beta adrenergic receptors

40. What is the MOA for the Fluoroquinolones?
Tetracycline - Doxycycline - Demeclocycline - Minocycline
Inhibit DNA Gyrase (topoisomerase II) - Bactericidal
- Ethanol - dialysis - & fomepizole
Megaloblastic anemia - Leukopenia - Granulocytopenia

41. What are two processes Corticosteroids inhibit leading to decreased inflammation?
Chronic Hepatitis A and B - Kaposi's Sarcoma
- Penicillin
Albuterol - tertbutaline
1. Phospholipase A2 is prevented from releasing arachidonic acid 2. Decreases protein synthesis thus lowering amount of Cyclooxygenase enzymes

42. Hydralazine - class and mechanism?
anticholinesterase glaucoma
vasodilator - increases cGMP to induce smooth muscle relaxation (arterioles>veins; afterload reduction)
Parkinson patients benefit from antimuscarinic agents through its inhibitory action within the indirect pathway.
- Infections - Trauma - Seizures - CO - Overdose - Metabolic - Alcohol (IT'S COMA)

43. What drugs target anticholinesterase
Digitoxin 168hrs Digoxin 40 hrs
Neostigmine - pyridostigmine edrophonium - physostigmine echothiophate
Constant FRACTION eliminated per unit time.(exponential)
Milk or Antacids - because divalent cations inhibit Tetracycline absorption in the gut

44. What are common side effects of Protease Inhibitors?
- Disulfram & also sulfonylureas - metronidazole
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
GI intolerance (nausea - diarrhea) - Hyperglycemia - Lipid abnormalities - Thrombocytopenia (Indinavir)
Tricyclic antidepressant.

45. For Heparin What is the Duration of action
Acute (hours)
Prevents the release of Ca from SR of skeletal muscle
Hormone synthesis inhibition (Gynecomastia) - Liver dysfunction (Inhibits CYP450) - Fever - Chills
not a sulfonamide - but action is the same as furosemide

46. What are three types of antacids and the problems that can result from their overuse?
Ciprofloxacin - Norfloxacin - Ofloxacin - Grepafloxacin - Enoxacin - Nalidixic acid
1. Aluminum hydroxide: constipation and hypophosphatemia 2. Magnesium hydroxide: diarrhea 3. Calcium carbonate: Hypercalcemia - rebound acid increase - All may cause hypokalemia
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).

47. Which drug(s) cause this reaction: Tardive dyskinesia?
- Antipsychotics
Competitive inibitor of progestins at progesterone receptors.
In treatment of malignant hyperthermia - due to concomitant use of halothane and succinylcholine. Also in neuroleptic malignant syndrome - a toxicity of antipsychotic drugs.
1. Addison's disease 2. Inflammation 3. Immune suppression 4. Asthma

48. List the specific antidote for this toxin: Warfarin
ACE inhibitor.
- Vitamin K & fresh frozen plasma
Na/K ATPase
In treatment of malignant hyperthermia - due to concomitant use of halothane and succinylcholine. Also in neuroleptic malignant syndrome - a toxicity of antipsychotic drugs.

49. K+ sparing diuretics - toxicity?
Hypersensitivity reactions
hyperkalemia - endocrine effects (gynecomastia - anti - androgen)
Md= (CpxCL)/F Cp= plas. Conc. CL=clear. F=bioaval.
Parkinson patients benefit from antimuscarinic agents through its inhibitory action within the indirect pathway.

50. Name the Protease Inhibitors (4)
Sulfamethoxazole (SMZ) - Sulfisoxazole - Triple sulfas - Sulfadiazine
GI discomfort - Acute cholestatic hepatitis - Eosinophilia - Skin rashes
GI disturbances.
Saquinavir - Ritonavir - Indinavir - Nelfinavir