Test your basic knowledge |

USMLE Step 1 Pharmacology

Subjects : health-sciences, usmle-step-1

Instructions:

Answer 50 questions in 15 minutes.
If you are not ready to take this test, you can study here.
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 are two toxicities of the Sulfonylureas?
Blocks Peptide Bond formation at the 50S subunit - Bacteriostatic
proximal convoluted tubule
Aminoglycosides
1. Hypoglycemia (more common with 2nd - generation drugs: glyburide - glipizide) 2. Disulfiram - like effects (not seen with 2nd - generation drugs).

2. What are five toxicities associated with Tacrolimus (FK506)?
Gram + - Gram - - Norcardia - Chlamydia
1. Significant: nephrotoxicity 2. Peripheral neuropathy 3. Hypertension 4. Pleural effusion 5. Hyperglycemia.
Parkinson patients benefit from antimuscarinic agents through its inhibitory action within the indirect pathway.
Blastomyces - Coccidioides - Histoplasma - C. albicans; Hypercortisolism

3. For Heparin What is the Onset of action
- Airway - Breathing - Circulation - Dextrose (thiamine & narcan) - ABCD
Decrease the production of leukotrienes and protaglandins by inhibiting phospholipase A2 and expression of COX-2.
Rapid (seconds)
- Shifts the curve to the right - increases Km

4. How does angiotensin II affect NE release?
1. Infertility (pulsatile) 2. Prostate cancer (continuous: use with flutamide) 3. Uterine fibroids
physostigmine
TMP- SMZ (DOC) - aerosolized pentamidine
It acts presynaptically to increase NE release.

5. What are the clinical uses for Imipenem/cilastatin?
- Metronidazole - certain cephalosporins - procarbazine - sulfonylureas
Ganciclovir is more toxic to host enzymes
alpha -1 > alpha -2; used as a pupil dilator - vasoconstrictor - and for nasal decongestion
Gram + cocci - Gram - rods - and Anerobes

6. What is the mechanism of action of Probenacid used to treat chronic gout?
Triple Therapy' 2 Nucleoside RT Inhibitors with a Protease Inhibitor
Hypersensitivity reactions
Lovastatin - Pravastatin - Simvastatin - Atorvastatin
Inhibits reabsorption of uric acid.

7. List the specific antidote for this toxin: Acetaminophen
1. Significant: nephrotoxicity 2. Peripheral neuropathy 3. Hypertension 4. Pleural effusion 5. Hyperglycemia.
1. Renal damage 2. Aplastic anemia 3. GI distress
- N- acetylcystine
Prevents the release of ACh - Which results in muscle paralysis.

8. Which RT inhibitor causes Megaloblastic Anemia?
Neostigmine - pyridostigmine edrophonium - physostigmine echothiophate
AZT
Suramin
Fast vs. Slow Acetylators

9. What is the memory key for the action of Sildenafil (Viagra)?
NO AP duration effect. useful in V- tach that progresses to V- fib and in intractable SVT Last RESORT
Gram - rods: Klebsiella species - Pseudomonas species - Serratia species
Chronic (weeks or months)
Sildenafil fills the penis

10. What is the MOA for Methicillin - Nafcillin - and Dicloxacillin?
Initially vasoconstriction would increase bp - but then it acts on central alpha -2 receptors to decrease adrenergic outflow resulting in decreased bp.
Same as penicillin. Act as narrow spectrum antibiotics
- Tetracycline
- Deferoxamine

11. Beta Blockers - CV toxicity?
bradycardia - AV block - CHF
Sulfonamide Loop Diuretic. Inhibits ion co - transport system of thick ascending loop. Abolishes hypertonicity of the medulla - thereby preventing concentration of the urine.
Misoprostol is a PGE1 analog that increases the production and secretion of the gastic mucous barrier.
- Constant AMOUNT eliminated per unit time. - Etoh & ASA

12. What are the clinical indications for bethanechol?
Does not cross
Activates cholinergic receptors on bladder and bowel smooth muscle - alleviating post - op and neurogenic ileus and urinary retention.
not a sulfonamide - but action is the same as furosemide
Chronic (weeks or months)

13. What Sulfonamides are used for simple UTIs?
ACIDazolamide' causes acidosis
- Oral Contraceptives
Triple sulfas or SMZ
Beta1 more than B2

14. List the specific antidote for this toxin: Methanol & Ethylene glycol
- Ethanol - dialysis - & fomepizole
Pralidoxime regenerates active cholinesterase.
- Oral Contraceptives
- Vinca alkaloids(inhibit MT) - Paclitaxel

15. What is the loading dose formula?
Ld= (CpxVd)/F Cp=plasma conc. F= Bioaval.
first dose orthostatic hypotension - dizziness - headache
proarrhythmic
Prevents the release of calcium from the sarcoplasmic reticulum of skeletal muscle.

16. What enzyme is responsible for the breakdown of ACh in the synaptic cleft?
Stimulates beta adrenergic receptors
Methylation of rRNA near Erythromycin's ribosome binding site
Acetylcholinesterase; ACh is broken down into choline and acetate.
Bismuth and Amoxicillin or Tetracycline; against Helobacter pylori

17. Which cancer drugs effect nuclear DNA (4)?
Activates cholinergic receptors on bladder and bowel smooth muscle - alleviating post - op and neurogenic ileus and urinary retention.
- Alkalating agents+cisplatin - Doxorubicin+Dactinomycin - Bleomycin - Etoposide
Erectile dysfunction.
Atropine pts are suffering from Cholinestrase inhibitor poisining (Nerve gas/Organophosphate poisining)

18. What are Aminoglycosides synergistic with?
Beta - lactam antibiotics
competitive inhibirot of aldosterone in the cortical collecting tubule
depresses ectopic pacemakers - especially in digoxin toxicity
1. Infertility (pulsatile) 2. Prostate cancer (continuous: use with flutamide) 3. Uterine fibroids

19. What is the mechanism of action of the Alpha - glucosidase inhibitors?
Inhibit intestinal bursh border Alpha - glucosidases; delayed hydrolysis of sugars and absorption of sugars leading to decresed postprandial hyperglycemia.
Tricyclic antidepressant.
Phosphorylation by a Viral Kinase
Amphetamine and Ephedrine

20. How is Amphotericin B administered for fungal meningitis?
Ld= (CpxVd)/F Cp=plasma conc. F= Bioaval.
hypertension - angina - arrhythmias
first dose orthostatic hypotension - dizziness - headache
Intrathecally

21. List the specific antidote for this toxin: Carbon monoxide
scopolamine
- Chloramphenicol
-100% oxygen - hyperbaric
Prefers beta's at low doses - but at higher doses alpha agonist effects are predominantly seen.

22. What is combined with Ampicillin - Amoxicillin - Carbenicillin - Piperacillin - and Ticarcillin to enhance their spectrum?
Clavulanic acid
Prevents the release of ACh - Which results in muscle paralysis.
- Penicillamine
Amphetamine and Ephedrine

23. Acetazolamide - toxicity?
- Acetaldehyde - Nausea - vomiting - headache - & hypotension
Headache - flushing - dyspepsia - blue - green color vision.
all except the K+ sparing diuretics Spironolactone - Triamterene - Amiloride
hyperchloremic metabolic acidosis - neuropathy - NH3 toxicity - sulfa allergy

24. What is the category of drug names ending in - barbital (e.g. Phenobarbital)
Babiturate.
The only local anesthetic with vasoconstrictive properties.
Ipratropium
Pretreat with antihistamines and a slow infusion rate

25. What is the category of drug names ending in - ane (e.g. Halothane)
Inhalational general anesthetic.
Pentavalent Antimony
- Nitrate - hydroxocobalamin thiosulfate
Gram + cocci - Haemophilus influenza - Enterobacter aerogenes - Neisseria species - P. mirabilis - E. coli - K. pneumoniae - Serratia marcescens ( HEN PEcKS )

26. What is the MOA for Vancomycin?
1) Aminoglycosides = bactericidal 2) Tetracyclines = bacteriostatic
The COX-2 inhibitors should not have the corrosive effects of other NSAIDs on the gastrointestinal lining.
Inhibits cell wall mucopeptide formation - Bactericidal
Nephrotoxicity

27. Which antimuscarinic agents are used in producing mydriasis and cycloplegia?
None. No - because atropine would block the postganglionic muscarinic receptors involved in sweat gland stimulation.
atropine - homatropine - tropicamide
ARF - shock - drug overdose - decrease intracranial/intraocular pressure
Penicillin - Cephalosporins - Vancomycin - Aminoglycosides - Fluoroquinolones - Metronidazole

28. Which drug(s) cause this reaction: G6PD hemolysis(8)?
- Oxalic acid - Acidosis & nephrotoxicity
PT
- Sulfonamides - INH - ASA - Ibuprofen - primaquine - nitrofurantoin /- pyrimethamine - chloramphenicol
Local anesthetic.

29. Nifedipine has similar action to?
- Antipsychotics
constipation - flushing - edema - CV effects (CHF - AV block - sinus node depression) - and torsade de pointes (Bepridil)
Nitrates
sedation - sleep alterations

30. Mannitol - clinical use?
Rare.
ARF - shock - drug overdose - decrease intracranial/intraocular pressure
Ld= (CpxVd)/F Cp=plasma conc. F= Bioaval.
Blastomyces - Coccidioides - Histoplasma - C. albicans; Hypercortisolism

31. What are common serious side effects of Aminoglycosides and What are these associated with?
- Chloramphenicol - benzene - NSAIDS - PTU - phenytoin
Nephrotoxicity (esp. with Cephalosporins) - Ototoxicity (esp. with Loop Diuretics)
Enterobacter
Intrathecally

32. What is the memory key for the effect of magnesium hydroxide overuse?
Mg = Must go to the bathroom.
proximal convoluted tubule
Bacitracin - Vancomycin
Cryptococcal meningitis in AIDS patients and Candidal infections of all types

33. Why is there a drop in systolic - mean - and diastolic bp with infusion of isoproterenol?
Inhibt Assembly of new virus by Blocking Protease Enzyme
Nucleosides
Stimulating beta receptors stimulates heart rate - but beta receptor induced vasodilation reduces peripheral resistance.
K+ wasting - metabolic alkalosis - hypotension - ototoxicity

34. Clonidine is the preferred sym pathomimetic tx of HTN in pts with renal disease - why??
Centrally acting alpha agonist - thus causing a decrease in central adrenergic outflow - spairing renal blood flow
torsade de pointes - excessive Beta block
Small lipid - soluble molecule
amphetamine and ephedrine

35. Mannitol - contraindications?
- Alkalating agents+cisplatin - Doxorubicin+Dactinomycin - Bleomycin - Etoposide
- Penicillamine
anuria - CHF
Give an antichloinesterase - neostigmine - edrophonium - etc

36. Adverse effects of Hydralazine?
Activates antithrombin III
Inhibits bacterial Dihydrofolate Reductase - Bacteriostatic
nausea - headache - lupus - like syndrome - reflex tachycardia - angina - salt retention
Gentamicin - Neomycin - Amikacin - Tobramycin - Streptomycin

37. What are the products and their toxicities of the metabolism of Methanol by / alcohol dehydrogenase?
- Normalize K+ - Lidocaine - & Anti - dig Mab
- Formaldehyde & formic acid - severe acidosis & retinal damage
Giant Roundworm (Ascaris) - Hookworm (Necator/Ancylostoma) - Pinworm (Enterobius)
Ganciclovir is more toxic to host enzymes

38. Cocaine shares is mechanism of action with What antidepressant
Ceftriaxone
- MT polymerization inhibitor(M phase) - MOPP - lymphoma - Willm's & choriocarcinoma - neurotoxicity and myelosuppression
Protease inhibitor.
TCA

39. Can Warfarin be used during pregnancy?
- Ethosuxamide - sulfonamides - lamotrigine
They inhibit reuptake of NE at the nerve terminal (as does cocaine).
Beta lactams - inhibit cell wall synthesis - Bactericidal
No - warfarin - unlike heparin - can cross the placenta.

40. What is the mechanism of action of Mifepristone (RU486)?
Competitive inibitor of progestins at progesterone receptors.
Nonspecific beta - agonist; desired effect is the relaxation of bronchial smooth muscle (Beta 2). Adverse effect is tachycardia (Beta 1).
Carbenicillin - Piperacillin - and Ticarcillin
Methylxanthine.

41. Beta Blockers - site of action?
Beta adrenergic receptors and Ca2+ channels (stimulatory)
all except the K+ sparing diuretics Spironolactone - Triamterene - Amiloride
Sulfonylureas are oral hypoglycemic agents - they are used to stimulate release of endogenous insulin in NIDDM (type -2).
Neutropenia

42. Loop diuretics (furosemide)- site of action?
NE acts presynaptically on alpha -2 receptors to inhibit its own release. ACh also acts presynaptically through M1 receptors to inhibit NE release.
thick ascending limb
Methylxanthine.
Nevirapine - Delavirdine

43. What are common toxic side effects of Sulfonamides? (5)
ARF - shock - drug overdose - decrease intracranial/intraocular pressure
NO
Oral treatment of superficial infections
- Hypersensitivity reactions - Hemolysis - Nephrotoxicity (tubulointerstitial nephritis) - Kernicterus in infants Displace other drugs from albumin (e.g. - warfarin)

44. What antimuscarinic agent is used in asthma and COPD?
Sucralfate cannot work in the presence of antacids or H2 blockers because it requires an acidic environment to polymerize.
Protease Inhibitors and Reverse Transcriptase Inhibitors
Ipratropium
Inhibits CMV DNA polymerase

45. How do Sulfonamides act on bacteria?
- Lithium
Mechanism unknown; possibly inhibits gluconeogenesis and increases glycolysis; effect is to decrease serum glucose levels
As PABA antimetabolites that inhibit Dihydropteroate Synthase - Bacteriostatic
- Constant AMOUNT eliminated per unit time. - Etoh & ASA

46. Antiarrhythmic class IB- effects?
cardiac depression - peripheral edema - flushing - dizziness - constipation
decrease AP duration - affects ischemic or depolarized Purkinje and ventricular system
Penicillin.
Acute coronary syndrome; coronary stenting. Decreases the incidence or recurrence of thrombotic stroke.

47. ACE inhibitors - clinical use?
decrease conduction velocity - increase ERP - increase PR interval
- inhibits HGPRT (pur. Syn.) - Luk - Lymph
Hypersensitivity reactions
hypertension - CHF - diabetic renal disease

48. What is the clinical use for Ampicillin and Amoxicillin?
Extended spectrum penicillin: certain Gram + bacteria and Gram - rods
- Atropine & pralidoxime
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)
Competitive inibitor of progestins at progesterone receptors.

49. Explain differences between full and partial agonists(2).
Tricyclic antidepressant.
- Act on same receptor - Full has greater efficacy
Ataxia - Dizziness - Slurred speech
Same as penicillin. Extended spectrum antibiotics

50. What is the category of drug names ending in - oxin (e.g. Digoxin)
- Vinca alkaloids(inhibit MT) - Paclitaxel
With supplemental Folic Acid
Cardiac glycoside (inotropic agent).
prevention of nodal arrhythmias (SVT)