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. Antiarrhythmic Class III- effects?
Prophylaxis for Influenza A - Rubella; Parkinson's disease
- Fluoroquinolones
Rifampin - Ethambutol - Streptomycin - Pyrazinamide - Isoniazid (INH)
increase AP duration - increase ERP - increase QT interval - for use When other arrhythmics fail

2. What is the major side effect for Carbenicillin - Piperacillin - and Ticarcillin?
reduce levels of Angiotensin II - thereby preventing the inactivation of bradykinin (a potent vasodilator); renin level is increased
Chronic anticoagulation.
Hypersensitivity reactions
CMV Retinitis in IC pts When Ganciclovir fails

3. What is the mechanism of action of Ticlopidine - Clopidogrel
Inhibits platelet aggregation by irreversibly inhibiting the ADP pathway involved in the binding of fibrinogen.
Overdose produces hepatic necrosis; acetaminophen metablolite depletes glutathione and forms toxic tissue adducts in liver.
for RSV
Protamine sulfate

4. Resistance mechanisms for Macrolides

Warning: Invalid argument supplied for foreach() in /var/www/html/basicversity.com/show_quiz.php on line 183

5. What is the mechanism of action of NSAIDs other than Aspirin?
Reversibly inhibit cyclooxygenase (COX I and COX II). Block prostaglandin synthesis.
Meningitis (H. influenza - N. meningitidis - S. pneumoniae) - Conserative treatment due to toxicities
BM suppression (neutropenia - anemia) - Peripheral neuropathy
1)Binds penicillin - binding proteins 2) Blocks transpeptidase cross - linking of cell wall 3) Activates autolytic enzymes

6. Adverse effect of Nitroprusside?
Ototoxicity - Hypokalemia - Dehydration - Allergy (sulfa) - Nephritis (interstitial) - Gout
1. Mycobacterium tuberculosis 2. Delays resistance to Dapsone When used of Leprosy 3. Used in combination with other drugs
Inhibits Viral DNA polymerase
cyanide toxicity (releases CN)

7. MOA of Succinylcholine
Prevents the release of Ca from SR of skeletal muscle
Carbenicillin - Piperacillin - and Ticarcillin
vascular sm. Mus.: Nifedipine>Diltiazem>Verapamil
- Estrogen receptor antagonist - Breast CA - increased endometrial CA risk

8. List the mechanism - clinical use - & toxicity of Cyclophosphamide.
very short acting
- Alkalating agent - NHL - Breast - ovary - & lung. - Myelosuppression - & hemorrhagic cystitis.
Nifedipine - Verapamil - Diltiazem
Inhibit Ergosterol synthesis

9. What is the MOA of Ganciclovir?
Inhibits CMV DNA polymerase
Captopril - Enalapril - Lisinopril
sedation - depression - nasal stuffiness - diarrhea
Keratin containing tissues - e.g. - nails

10. What is combined with Ampicillin - Amoxicillin - Carbenicillin - Piperacillin - and Ticarcillin to enhance their spectrum?
Binds to the Pyrophosphate Binding Site of the enzyme
Clavulanic acid
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.
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

11. Cocaine shares is mechanism of action with What antidepressant
TCA
Pralidoxime regenerates active cholinesterase.
1. Streptokinase 2. Urokinase 3. tPA (alteplase) - APSAC (anistreplase)
Inhibits platelet aggregation by irreversibly inhibiting the ADP pathway involved in the binding of fibrinogen.

12. Decrease Digoxin dose in renal failure?
Peptic ulcer disease.
YES
nausea - headache - lupus - like syndrome - reflex tachycardia - angina - salt retention
Keratin containing tissues - e.g. - nails

13. ADH antagonists - site of action?
collecting ducts
Liver
Megaloblastic anemia - Leukopenia - Granulocytopenia
Mebendazole/Thiabendazole - Pyrantel Pamoate

14. What are common toxicities related to Vancomycin therapy?

Warning: Invalid argument supplied for foreach() in /var/www/html/basicversity.com/show_quiz.php on line 183

15. What is the MOA for Rifampin?
DOC in diagnosing and abolishing AV nodal arrhythmias
Large anionic polymer - acidic
Inhibits DNA dependent RNA polymerase
- Lithium

16. Ryanodine - site of action?
Oxygen
Binds 30S subunit and prevents attachment of aminoacyl - tRNA - Bacteriostatic
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
blocks SR Ca2+ channels

17. What is the category of drug names ending in - cillin (e.g. Methicillin)
Penicillin.
proximal convoluted tubule - thin descending limb - and collecting duct
Mg = Must go to the bathroom.
Inhibit steroid synthesis - used in the treatment of polycystic ovarian syndrome to prevent hirsutism.

18. Which drug(s) cause this reaction: Gingival hyperplasia?
penicillinase resistant
thiazides - amiloride
- Phenytoin
Interferes with microtubule function - disrupts mitosis - inhibits growth

19. What is a sign of toxicity with the use of thrombolytics?
- Nitrate - hydroxocobalamin thiosulfate
cross - allergenic
Vibrio cholerae Acne Chlamydia Ureaplasma Urealyticum Mycoplasma pneumoniae Borrelia burgdorferi (Lyme's) Rickettsia Tularemia
Bleeding.

20. List the specific antidote for this toxin: Opioids
- B51Naloxone / naltrexone (Narcan)
Disulfiram - like reaction with EtOH - Headache
- Chloramphenicol - benzene - NSAIDS - PTU - phenytoin
reduce levels of Angiotensin II - thereby preventing the inactivation of bradykinin (a potent vasodilator); renin level is increased

21. What enzyme is responsible for the degredation of Ach
Acetylcholine esterase
Prevents the release of Ca from SR of skeletal muscle
Chloramphenicol - Erythromycin/macrolides - Lincomycin - Clindamycin - Streptogramins (quinupristin - dalfopristin)
toxic

22. Adenosine - clinical use?
Misoprostol is a PGE1 analog that increases the production and secretion of the gastic mucous barrier.
effective in torsade de pointes and digoxin toxicity
post MI and digitalis induced arrhythmias
DOC in diagnosing and abolishing AV nodal arrhythmias

23. What is the category - desired effect - and possible mechanism of Theophylline in treating Asthma?
Methylzanthine; desired effect is bronchodilation - may cause bronchodilation by inhibiting phosphodiesterase - enzyme involved in degrading cAMP (controversial).
1. Bleeding 2. Teratogenicity 3. Drug - drug interactions
fetal renal toxicity - hyperkalemia
Ciprofloxacin - Norfloxacin - Ofloxacin - Grepafloxacin - Enoxacin - Nalidixic acid

24. Which of epi - norepi - or isoproterenol results in bradycardia?
Ciprofloxacin - Norfloxacin - Ofloxacin - Grepafloxacin - Enoxacin - Nalidixic acid
- DNA intercalator - testicular & lymphomas - Pulmonary fibrosis mild myelosuppression.
Norepinephrine
Beta 2 agonist; used as a long - acting agent for prophylaxis. Adverse effects are tremor and arrhythmia.

25. Acetaldehyde is metabolized by Acetaldehyde dehydrogenase - Which drug inhibs this enzyme?
GI distress - Skin rash - and Seizures at high plasma levels
- Constant AMOUNT eliminated per unit time. - Etoh & ASA
- Disulfram & also sulfonylureas - metronidazole
Meningitis (H. influenza - N. meningitidis - S. pneumoniae) - Conserative treatment due to toxicities

26. What are four advantages of newer low - molecular - weight heparins (Enoxaparin)?
Acetylcholinesterase; ACh is broken down into choline and acetate.
fetal renal toxicity - hyperkalemia
- Daunorubicin & Doxorubicin
1. Better bioavailability 2. 2 to 4 times longer half life 3. Can be administered subcutaneously 4. Does not require laboratory monitoring

27. How are Interferons (INF) used clinically?

Warning: Invalid argument supplied for foreach() in /var/www/html/basicversity.com/show_quiz.php on line 183

28. List the specific antidote for this toxin: Acetaminophen
- Cimetidine - ketoconazole - spironolactone - digitalis - EtOH - estrogens
- N- acetylcystine
AV nodal cells
- Weak Acids>Alkinalize urine(CO3) to remove more - Weak bases>acidify urine to remove more

29. What is the MOA for the Fluoroquinolones?
severe orthostatic hypotension - blurred vision - constipation - sexual dysfunction
Epinephrine
Gram + cocci - Gram - rods - and Anerobes
Inhibit DNA Gyrase (topoisomerase II) - Bactericidal

30. What is the category of drug names ending in - oxin (e.g. Digoxin)
Norepinephrine (Alpha1 -2 and beta 1)
decrease conduction velocity - increase ERP - increase PR interval
Cardiac glycoside (inotropic agent).
Inhibits cell wall synthesis ( binds to PBP3). A monobactam

31. MOA: Block mRNA synthesis
- Vinca alkaloids(inhibit MT) - Paclitaxel
Blocks Norepi - but not Dopamine
- EDTA - dimercaprol - succimer - & penicillamine
Rifampin

32. What is the clinical use for Sucralfate?
Peptic ulcer disease.
Mechanism unknown; possibly inhibits gluconeogenesis and increases glycolysis; effect is to decrease serum glucose levels
Foscarnet = pyroFosphate analog
1. Mycobacterium tuberculosis 2. Delays resistance to Dapsone When used of Leprosy 3. Used in combination with other drugs

33. Acetazolamide causes?

Warning: Invalid argument supplied for foreach() in /var/www/html/basicversity.com/show_quiz.php on line 183

34. What is the difference between the affinity for beta receptors between albuterol/terbutaline and dantroline?
Inhibits cell wall mucopeptide formation - Bactericidal
Dobutamine has more of an affintiy for beta -1 than beta -2 - and is used for treating heart failure and shock. Albuterol and terbutaline is the reverse - and is used in treatment of acute asthma.
INH: Injures Neurons and Hepatocytes
Blocks translocation - binds to the 23S rRNA of the 50S subunit - Bacteriostatic

35. Which RT inhibitors cause Lactic Acidosis?
Nucleosides
Oxygen
Malaria (P. falciparum)
alpha -1 > alpha -2; used as a pupil dilator - vasoconstrictor - and for nasal decongestion

36. Hydrochlorothiazide - toxicity? (hyperGLUC - plus others)
Hypokalemic metabolic alkalosis - hyponatremia - hyperGlycemia - hyperLipidemia - hyperUricemia - hyperCalcemia - sulfa allergy.
Benzodiazepine.
Tetracycline - Doxycycline - Demeclocycline - Minocycline
HSV - VZV - EBV - Mucocutaneous and Genital Herpes Lesions - Prophylaxis in Immunocompromised pts

37. Bretyllium - toxicity?
new arrhythmias - hypotension
increase AP duration - increase ERP - increase QT interval - for use When other arrhythmics fail
Short.
toxic

38. What are the clinical uses for 3rd Generation Cephalosporins?
glaucoma - urinary alkalinization - metabolic alkalosis - altitude sickness
troponin - tropomyosin system
BM suppression (neutropenia - anemia) - Peripheral neuropathy
1) Serious Gram - infections resistant to other Beta lactams 2) Meningitis (most penetrate the BBB)

39. What is an additional side effect of Methicillin?
Local anesthetic.
Interstitial nephritis
Terminal D- ala of cell wall replaced with D- lac; Decreased affinity
decrease AP duration - affects ischemic or depolarized Purkinje and ventricular system

40. Does Heparin have a long - medium - or short half life?
Short.
Overdose produces hepatic necrosis; acetaminophen metablolite depletes glutathione and forms toxic tissue adducts in liver.
Finasteride inhibits 5 Alpha - reductase - this decreases the conversion of testosterone to dihydrotestosterone - useful in BPH
WEPT: Warfarin affects the Extrinsic pathway and prolongs the PT.

41. What is the category of drug names ending in - azol (e.g. Ketoconazole)
None. No - because atropine would block the postganglionic muscarinic receptors involved in sweat gland stimulation.
Antifungal.
Disulfiram - like reaction with EtOH - Headache
1) Hypersensitivity reactions 2) Increased nephrotoxicity of Aminoglycosides 3) Disulfiram - like reaction with ethanol (those with a methylthiotetrazole group - e.g. - cefamandole)

42. What cholinergic inhibitor acts by directly inhibiting Ach release at the presynaptic terminal
1. Peptic ulcer 2. Gastritis 3. Esophageal reflux 4. Zollinger - Ellison syndrome
Beta -2 agonist.
Premature infants - because they lack UDP- glucuronyl transferase
Botulinum

43. MOA: Block cell wall synthesis by inhib. Peptidoglycan cross - linking (7)
Tricyclic antidepressant.
DOC in diagnosing and abolishing AV nodal arrhythmias
loop diuretics - spironolactone
Penicillin - Ampicillin - Ticarcillin - Pipercillin - Imipenem - Aztreonam - Cephalosporins

44. What are the clinical uses for Aztreonam?
Polymyxins
Treatment of hypertension - especially with renal disease (lowers bp centrally - so flow is maintained to kidney).
Choline acetyltransferase
Gram - rods: Klebsiella species - Pseudomonas species - Serratia species

45. What type of gout is treated with Probenacid?
Inhibits IMP Dehydrogenase (competitively) - and therefore blocks Guanine Nucleotide synthesis
1. Acarbose 2. Miglitol
Chronic gout.
When pts have Low CD4+ (< 500 cells/cubic mm) or a High Viral Load

46. How can the t1/2 of INH be altered?
- Formaldehyde & formic acid - severe acidosis & retinal damage
Blocks viral penetration/uncoating; may act to buffer the pH of the endosome
Beta1 more than B2
Fast vs. Slow Acetylators

47. Antiarrhythmic class II- toxicity?
Rifampin - Ethambutol - Streptomycin - Pyrazinamide - Isoniazid (INH)
impotence - exacerbation of asthma - CV effects - CNS effects - may mask hypoclycemia
Increased systolic and pulse pressure - decreased diastolic pressure - and little change in mean pressure.
Flutamide is a nonsteroidal competitive inhibitor of androgens at the testosterone receptor - used in prostate carcinoma.

48. How is Vancomycin used clinically?
For serious - Gram + multidrug - resistant organisms
diuretics - sympathoplegics - vasodilators - ACE inhibitors - Angiotensin II receptor inhibitors
Binding to the presynaptic alpha 2 release modulating receptors
Antimetabolite derivative of 6- mercaptopurine that interferes with the metablolism and synthesis of nucleic acid.

49. Classes of antihypertensive drugs?
Cephalosporins
Topical and Oral - for Oral Candidiasis (Thrush)
diuretics - sympathoplegics - vasodilators - ACE inhibitors - Angiotensin II receptor inhibitors
pulmonary fibrosis - corneal deposits - hepatotoxicity - skin deposits resulting in photodermatitis - neurologic effects - consitpation - CV (bradycardia - heart block - CHF) - and hypo - or hyperthyroidism.

50. What is a common drug interaction associated with Griseofulvin?
- NaHCO3
CMV - esp in Immunocompromised patients
1. Bleeding 2. Thrombocytopenia 3. Drug - drug interactions
Increases coumadin metabolism