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. Name the common Nucleoside Reverse Transcriptase Inhibitors
physostigmine
proarrhythmic
Immediate anticoagulation for PE - stroke - angina - MI - DVT.
Zidovudine (AZT) - Didanosine (ddI) - Zalcitabine (ddC) - Stavudine (d4T) - Lamivudine (3TC)

2. What is the clinical use for Warfarin?
1. Better bioavailability 2. 2 to 4 times longer half life 3. Can be administered subcutaneously 4. Does not require laboratory monitoring
Chronic anticoagulation.
Acetylcholine esterase
Beta -2 agonist.

3. K+- clinical use?
- Steroids - Tamoxifen
- Haloperidol - chlorpromazine - reserpine - MPTP
depresses ectopic pacemakers - especially in digoxin toxicity
It acts presynaptically to increase NE release.

4. How does dantrolene work?
Prevents the release of calcium from the sarcoplasmic reticulum of skeletal muscle.
- Ethanol - dialysis - & fomepizole
Penicillin - Cephalosporins - Vancomycin - Aminoglycosides - Fluoroquinolones - Metronidazole
prevention of nodal arrhythmias (SVT)

5. Which drug(s) cause this reaction: Hot flashes?
Treatment of hypertension - especially with renal disease (lowers bp centrally - so flow is maintained to kidney).
Beta Blockers
Hypersensitivity reactions
- Tamoxifen

6. What is the category of drug names ending in - zosin (e.g. Prazosin)
- Alkalate DNA - Brain tumors - CNS toxicity
Modification via Acetylation - Adenylation - or Phosphorylation
Digoxin=urinary Digitoxin=biliary
Alpha -1 antagonist

7. What is a mnemonic to remember Amantadine's function?
Chronic (weeks or months)
Blocks Influenza A and RubellA; causes problems with the cerebellA
NO
Inhibit viral DNA polymerase

8. What is the clinical use for Ampicillin and Amoxicillin?
pulmonary fibrosis - corneal deposits - hepatotoxicity - skin deposits resulting in photodermatitis - neurologic effects - consitpation - CV (bradycardia - heart block - CHF) - and hypo - or hyperthyroidism.
Glycoproteins from leukocytes that block various stages of viral RNA and DNA synthesis
1. Hydrocortisone 2. Predisone 3. Triamcinolone 4. Dexamethasone 5. Beclomethasone
Extended spectrum penicillin: certain Gram + bacteria and Gram - rods

9. Name several common Macrolides (3)
- acetylation - glucuron. - & sulfation - Conjugation - Polar product
Erythromycin - Azithromycin - Clarithromycin
Hemolytic anemia
hyperkalemia - endocrine effects (gynecomastia - anti - androgen)

10. Antiarrhythmic class IB- clinical uses?
1. Meningococcal carrier state 2. Chemoprophylaxis in contacts of children with H. influenzae type B
post MI and digitalis induced arrhythmias
Beta 2 agonist; used as a long - acting agent for prophylaxis. Adverse effects are tremor and arrhythmia.
Treatment of hypertension - especially with renal disease (lowers bp centrally - so flow is maintained to kidney).

11. What is the mechanism of Leuprolide?
1. Skin rash 2. Agranulocytosis (rare) 3. Aplastic anemia
Prophylaxis for Influenza A - Rubella; Parkinson's disease
scopolamine
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

12. Name some common Tetracyclines (4)
Antibiotic - protein synthesis inhibitor.
Tetracycline - Doxycycline - Demeclocycline - Minocycline
- NaHCO3
Gram + cocci - Haemophilus influenza - Enterobacter aerogenes - Neisseria species - P. mirabilis - E. coli - K. pneumoniae - Serratia marcescens ( HEN PEcKS )

13. MOA: Bactericidal antibiotics
Hexamethonium is a nicotinic antagonist - and thus is a ganglionic blocker.
Babiturate.
Penicillin - Cephalosporins - Vancomycin - Aminoglycosides - Fluoroquinolones - Metronidazole
Nifedipine - Verapamil - Diltiazem

14. What do you treat Nematode/roundworm (pinworm - whipworm) infections with?
Modification via Acetylation - Adenylation - or Phosphorylation
AZT
1. Weight gain 2. Hepatotoxicity (troglitazone)
Mebendazole/Thiabendazole - Pyrantel Pamoate

15. What is clinical use for Carbenicillin - Piperacillin - and Ticarcillin?
Bleeding.
Inhibit intestinal bursh border Alpha - glucosidases; delayed hydrolysis of sugars and absorption of sugars leading to decresed postprandial hyperglycemia.
Pseudomonas species and Gram - rods
- Normalize K+ - Lidocaine - & Anti - dig Mab

16. Isopoterenol was given to a patient with a developing AV block - why?
Acute coronary syndrome; coronary stenting. Decreases the incidence or recurrence of thrombotic stroke.
distal convoluted tubule (early)
Severe Gram - rod infections.
Stimulates beta adrenergic receptors

17. Name three calcium channel blockers?
Paranteral (IV - SC)
Nifedipine - Verapamil - Diltiazem
Long.
Bind cell membrane - disrupt osmotic properties - Are Cationc - Basic and act as detergents

18. What is the mechanism of action of Cyclosporine?
- Sulfonamides - INH - ASA - Ibuprofen - primaquine - nitrofurantoin /- pyrimethamine - chloramphenicol
Protease Inhibitors and Reverse Transcriptase Inhibitors
bradycardia - AV block - CHF
Binds to cyclophilins (peptidyl proline cis - trans isomerase) - blocking the differentiation and activation of T cells mainly by inhibiting the production of IL-2 and its receptor.

19. What are Fluoroquinolones indicated for? (3)
diuretics - sympathoplegics - vasodilators - ACE inhibitors - Angiotensin II receptor inhibitors
Acetylcholine esterase
1.Gram - rods of the Urinary and GI tracts (including Pseudomonas) 2.Neisseria 3. Some Gram + organisms
Hypersensitivity reactions

20. What is a common side effect of Misoprostol?
NO
Diarrhea
1) Aminoglycosides = bactericidal 2) Tetracyclines = bacteriostatic
The COX-2 inhibitors should not have the corrosive effects of other NSAIDs on the gastrointestinal lining.

21. Secretion of What drug is inhibited by Probenacid used to treat chronic gout?
Inhibits reabsorption of uric acid.
Penicillin.
Pralidoxime regenerates active cholinesterase.
- Nitrate - hydroxocobalamin thiosulfate

22. Name three Antiarrhythmic drugs in class IB.
Babiturate.
increase AP duration - increase ERP - increase QT interval - for use When other arrhythmics fail
Phosphorylation by a Viral Kinase
Lidocaine - Mexiletine - Tocainide

23. Side effects of Isoniazid (INH)?
Hemolysis (if G6PD deficient) - Neurotoxicity - Hepatotoxicity - SLE- like syndrome
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.
Norepinephrine
Pentamidine

24. Which of the following would atropine administration cause? Hypothermia - bradycardia - excess salivation - dry flushed skin - or diarrhea
Dry flushed skin - due to inhibition of sympathetic post - ganglionic blockade on muscarinic receptors of sweat glands. All others are opposite of What would be expected.
Phosphorylation by a Viral Kinase
Amphetamine and Ephedrine
Primaquine

25. Resistance mechanisms for Sulfonamides
Altered bacterial Dihydropteroate Synthetase - Decreased uptake - or Increased PABA synthesis
Nonspecific beta - agonist; desired effect is the relaxation of bronchial smooth muscle (Beta 2). Adverse effect is tachycardia (Beta 1).
- Topo II inhibitor(GII specific) - Oat cell of Lung & prostate - & testicular - Myelosuppression & GI irritation.
Cephalosporins

26. How is Ganciclovir activated?
blocks SR Ca2+ channels
Foscarnet = pyroFosphate analog
reversible SLE- like syndrome
Phosphorylation by a Viral Kinase

27. List the specific antidote for this toxin: Benzodiazepines
Increases mean - systolic - and diastolic bp - while there is little change in pulse pressure.
- Tricyclic antidepressants
Blocking muscarinic receptors in the circular fibers of the eye - results in unopposed action of radial muscles to dilate.
- Flumazenil

28. Which drug(s) cause this reaction: Hepatitis?
AluMINIMUM amount of feces.
- Penicillamine
- Isoniazid
1) Chloramphenical = bacteriostatic 2) Erythromycin = bacteriostatic 3) Lincomycin = bacteriostatic 4)cLindamycin = bacteriostatic

29. For Heparin What is the Onset of action
ACIDazolamide' causes acidosis
Rapid (seconds)
Tricyclic antidepressant.
Reversible block of histamine H2 receptors

30. What is the clinical use for Nystatin?
scopolamine
Topical and Oral - for Oral Candidiasis (Thrush)
- Penicillamine
1. Renal damage 2. Aplastic anemia 3. GI distress

31. Adverse effects of Captopril?
Treatment of infertility.
fetal renal toxicity - hyperkalemia - Cough - Angioedema - Proteinuria - Taste changes - hypOtension - Pregnancy problems - Rash - Increased renin - Lower Angiotensin II (CAPTOPRIL)
Praziquantel
Bacitracin - Vancomycin

32. When is Rifampin not used in combination with other drugs?
1. Hypoglycemia (more common with 2nd - generation drugs: glyburide - glipizide) 2. Disulfiram - like effects (not seen with 2nd - generation drugs).
1. Meningococcal carrier state 2. Chemoprophylaxis in contacts of children with H. influenzae type B
Polymyxins
Used in combination therapy with SMZ to sequentially block folate synthesis

33. Antimicrobial prophylaxis for Syphilis
1. Bleeding 2. Thrombocytopenia 3. Drug - drug interactions
carbonic anhydrase inhibitors - K+ sparing diuretics
reduce levels of Angiotensin II - thereby preventing the inactivation of bradykinin (a potent vasodilator); renin level is increased
Benzathine penicillin G

34. What is the MOA of Isoniazid (INH)?
Pyridoxine (B6) administration
Decreases synthesis of Mycolic Acid
Staphlococcus aureus and Clostridium difficile (pseudomembranous colitis)
Inhibits organification and coupling of thyroid hormone synthesis. Also decreases peripheral conversion of T4 to T3.

35. Beta Blockers - site of action?
Disulfiram - like reaction with EtOH - Headache
AmOxicillin has greater Oral bioavailability
Beta adrenergic receptors and Ca2+ channels (stimulatory)
Heparin catalyzes the activation of antithrombin III.

36. Why would you use pralidoxime after exposure to an organophosphate?
Digitoxin>95% Digoxin 75%
ACIDazolamide' causes acidosis
Penicillin - Cephalosporins - Vancomycin - Aminoglycosides - Fluoroquinolones - Metronidazole
Pralidoxime regenerates active cholinesterase.

37. Which drug(s) cause this reaction: G6PD hemolysis(8)?
Sulfonamides - Trimethoprim
Pyridoxine (B6) administration
- Sulfonamides - INH - ASA - Ibuprofen - primaquine - nitrofurantoin /- pyrimethamine - chloramphenicol
- EDTA - dimercaprol - succimer - & penicillamine

38. What are signs of Sildenafil (Viagra) toxicity?
- Haloperidol - chlorpromazine - reserpine - MPTP
1. Phospholipase A2 is prevented from releasing arachidonic acid 2. Decreases protein synthesis thus lowering amount of Cyclooxygenase enzymes
Headache - flushing - dyspepsia - blue - green color vision.
1. Hydrocortisone 2. Predisone 3. Triamcinolone 4. Dexamethasone 5. Beclomethasone

39. Beta Blockers - CNS toxicity?
Gram + cocci - Gram - rods - and Anerobes
sedation - sleep alterations
Rapid (seconds)
Sulfamethoxazole (SMZ) - Sulfisoxazole - Triple sulfas - Sulfadiazine

40. What are two conditions in Which COX-2 inhibitors might be used?
- Alkalates DNA - CML - Pulmonary fibrosis hyperpigmentation
Oral treatment of superficial infections
Rheumatoid and osteoarthritis.
new arrhythmias - hypotension

41. What populations are Floroquinolones contraindicated in? Why?
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)
- Ethanol - dialysis - & fomepizole
Ld= (CpxVd)/F Cp=plasma conc. F= Bioaval.
Pregnant women - Children; because animal studies show Damage to Cartilage

42. What is the category of drug names ending in - operidol (e.g. Haloperidol)
Butyrophenone (neuroleptic).
- S- phase anti - metabolite Pyr analogue - Colon - solid tumors - & BCC/ - Irreversible myelosuppression
Beta 2 agonist; desired effect is the relaxation of bronchial smooth muscle (Beta 2). Use during acute exacerbation.
- Niacin - Ca++ channel blockers - adenosine - vancomycin

43. For Heparin What is the Duration of action
Used in combination therapy with SMZ to sequentially block folate synthesis
Acute (hours)
Aminoglycosides - Tetracyclines
Overdose produces hepatic necrosis; acetaminophen metablolite depletes glutathione and forms toxic tissue adducts in liver.

44. What is the mechanism of action of Acetaminophen?
proarrhythmic
Anaerobic infections (e.g. - B. fragilis - C. perfringens)
Reversibly inhibits cyclooxygenase - mostly in CNS. Inactivated peripherally.
Lipoxygenase

45. Triamterene and amiloride - mechanism?
Same as penicillin. Extended spectrum antibiotics
- NaHCO3
Close K+ channels in Beta - cell membrane leading to cell depolarization causing insulin release triggered by increase in Calcium ion influx.
block Na+ channels in the cortical collecting tubule

46. What is the memory key to remember Which pathway (extrinsic vs. intrinsic) and Which lab value Warfarin affects?
distal convoluted tubule (early)
Mebendazole/Thiabendazole - Pyrantel Pamoate
WEPT: Warfarin affects the Extrinsic pathway and prolongs the PT.
AZT

47. Ethacrynic Acid - mechanism?
not a sulfonamide - but action is the same as furosemide
Chloramphenicol - Erythromycin/macrolides - Lincomycin - Clindamycin - Streptogramins (quinupristin - dalfopristin)
Phosphorylation by a Viral Kinase
- Topo II inhibitor(GII specific) - Oat cell of Lung & prostate - & testicular - Myelosuppression & GI irritation.

48. Is resistant to penicillinase?
Cestode/tapeworm (e.g. - D. latum - Taenia species Except Cysticercosis
Zidovudine (AZT) - Didanosine (ddI) - Zalcitabine (ddC) - Stavudine (d4T) - Lamivudine (3TC)
Imipenem
The COX-2 inhibitors should not have the corrosive effects of other NSAIDs on the gastrointestinal lining.

49. Guanethidine enhances the release of Norepi?
very short acting
Antileukotriene; blocks leukotriene receptors.
No - it inhibits the release of Nor Epi
toxic

50. What is Metronidazole used for clinically?
GI discomfort
Receptors = D1=D2>beta>alpha - thus increasing heart rate (beta) and blood pressure (alpha vasoconstriction) while maintaining kidney perfusion (dopamine receptors)
Antiprotozoal: Giardia - Entamoeba - Trichomonas - Gardnerella vaginalis Anaerobes: Bacteroides - Clostridium
- DNA intercalator - testicular & lymphomas - Pulmonary fibrosis mild myelosuppression.