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 is the formula for Clearance (CL)
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
CL= (rate of elimination of drug/ Plasma drug conc.)
Sulfonamide Loop Diuretic. Inhibits ion co - transport system of thick ascending loop. Abolishes hypertonicity of the medulla - thereby preventing concentration of the urine.
cinchonism: HA - tinnitus - thrombocytopenia - torsade de pointes due to increased QT interval

2. Which drug(s) cause this reaction: Hepatitis?
- Isoniazid
They activate the ciliary muscle of the eye (open angle) and pupillary sphincter (narrow angle).
1. Acarbose 2. Miglitol
HTN - CHF - calcium stone formation - nephrogenic DI.

3. What is the MOA for the Cephalosporins?
proximal convoluted tubule
Beta lactams - inhibit cell wall synthesis - Bactericidal
Hemolytic anemia
Babiturate.

4. Are penicillinase resistant
Cell membrane Ca2+ channels of cardiac sarcomere
Methicillin - Nafcillin - and Dicloxacillin
Gram + - Gram - - Norcardia - Chlamydia
Lidocaine - Mexiletine - Tocainide

5. What is the enzyme inhibited - the effect of this inhibition - and the clinical use of the antiandrogren Finasteride?
CL= (rate of elimination of drug/ Plasma drug conc.)
Nitrates
Finasteride inhibits 5 Alpha - reductase - this decreases the conversion of testosterone to dihydrotestosterone - useful in BPH
fetal renal damage - hyperkalemia - Cough - Angioedema - Proteinuria - Taste changes - hypOtension - Pregnancy problems - Rash - Increased renin - Lower Angiotensin II (CAPTOPRIL)

6. Adverse effects of Captopril?
sedation - positive Coombs' test
Nephrotoxicity
fetal renal toxicity - hyperkalemia - Cough - Angioedema - Proteinuria - Taste changes - hypOtension - Pregnancy problems - Rash - Increased renin - Lower Angiotensin II (CAPTOPRIL)
1. Peptic ulcer 2. Gastritis 3. Esophageal reflux 4. Zollinger - Ellison syndrome

7. Antimicrobial prophylaxis for Meningococcal infection
Rifampin (DOC) - minocycline
1. Predisposes to viral infections and lymphoma 2. Nephrotoxic (preventable with mannitol diuresis)
severe orthostatic hypotension - blurred vision - constipation - sexual dysfunction
severe hypertension - CHF

8. Name two LPL stimulators.
Antifungal.
- Cloazapine - carbamazapine - colchicine - PTU
Gemfibrozil - Clofibrate
Leukotrienes increasing bronchial tone.

9. Mg+- clinical use?
Intrathecally
1. Renal damage 2. Aplastic anemia 3. GI distress
- Alkalating agent - NHL - Breast - ovary - & lung. - Myelosuppression - & hemorrhagic cystitis.
effective in torsade de pointes and digoxin toxicity

10. Resistance mechanisms for Sulfonamides
reversible SLE- like syndrome
Onchocerciasis ('river blindness'-- rIVER- mectin)
- Metronidazole - certain cephalosporins - procarbazine - sulfonylureas
Altered bacterial Dihydropteroate Synthetase - Decreased uptake - or Increased PABA synthesis

11. Why are the Sulfonylureas inactive in IDDM (type -1)?
- Physostigmine salicylate
Because they require some residual islet function.
Inhibits xanthine oxidase - decresing conversion of xanthine to uric acid.
Methylzanthine; desired effect is bronchodilation - may cause bronchodilation by inhibiting phosphodiesterase - enzyme involved in degrading cAMP (controversial).

12. Which drug(s) cause this reaction: Disulfram - like reaction (4) ?
- Metronidazole - certain cephalosporins - procarbazine - sulfonylureas
Epinephrine
thick ascending limb
- Airway - Breathing - Circulation - Dextrose (thiamine & narcan) - ABCD

13. How do you treat coma in the ER (4)?
GI upset - Superinfections - Skin rashes - Headache - Dizziness
- Airway - Breathing - Circulation - Dextrose (thiamine & narcan) - ABCD
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.
Rheumatoid and osteoarthritis.

14. What enzyme is responsible for the production of Ach from Acetyl CoA and Choline
Sulfonamides - Trimethoprim
- Corticosteroids - heparin
Choline acetyltransferase
- Tricyclic antidepressants

15. Antiarrhythmic class IB- toxicity?
Bleeding.
NE acts presynaptically on alpha -2 receptors to inhibit its own release. ACh also acts presynaptically through M1 receptors to inhibit NE release.
local anesthetic. CNS stimulation or depression. CV depression.
1. Acarbose 2. Miglitol

16. Toxicities associated with Acyclovir?
Inhibition of 50S peptidyl transferase - Bacteriostatic
Give an antichloinesterase - neostigmine - edrophonium - etc
Delirium - Tremor - Nephrotoxicity
Indomethacin is used to close a patent ductus arteriosus.

17. How is Trimethoprim used clinically?
increased AP duration - increased ERP increased QT interval. Atrial and ventricular.
Used in combination therapy with SMZ to sequentially block folate synthesis
Clomiphene is a partial agonist at estrogen receptors in the pituitary gland. Prevents normal feedback inhibition and increses release of LH and FSHfrom the pituitary - Which stimulates ovulation.
1. Acarbose 2. Miglitol

18. Which cancer drugs work at the level of proteins(2)?
- Vinca alkaloids(inhibit MT) - Paclitaxel
Stimulates beta adrenergic receptors
Prevention of NSAID- induced peptic ulcers - maintains a PDA.
Aminoglycosides

19. What are three unwanted effects of Mifepristone?
- Methotrexate - 5 FU - 6 mercaptopurine
- Deferoxamine
Finasteride inhibits 5 Alpha - reductase - this decreases the conversion of testosterone to dihydrotestosterone - useful in BPH
1. Heavy bleeding 2. GI effects (n/v - anorexia) 3. Abdominal pain

20. Name some common Sulfonamides (4)
Decreases synthesis of Mycolic Acid
Sulfamethoxazole (SMZ) - Sulfisoxazole - Triple sulfas - Sulfadiazine
These B-2 agonists cause respiratory smooth muscle to relax.
bradycardia - AV block - CHF

21. Adverse effects of Nifedipine - verapamil?
- Metronidazole - certain cephalosporins - procarbazine - sulfonylureas
Beta antagonist.
dizziness - flushing - constipation (verapamil) - nausea
SLUD (salivation - Lacrimation - urination - Defecation)as well as airway secretion - GI motility - acid secretions

22. What is the MOA of Polymyxins?
Bind cell membrane - disrupt osmotic properties - Are Cationc - Basic and act as detergents
Modification via Acetylation
carbonic anhydrase inhibitors - K+ sparing diuretics
Acute coronary syndrome; coronary stenting. Decreases the incidence or recurrence of thrombotic stroke.

23. What are two toxicities of the Glitazones?
nausea - headache - lupus - like syndrome - reflex tachycardia - angina - salt retention
Sucralfate cannot work in the presence of antacids or H2 blockers because it requires an acidic environment to polymerize.
1. Weight gain 2. Hepatotoxicity (troglitazone)
Bactericidal for: Gram + rod and cocci - Gram - cocci - and Spirochetes

24. List the mechanism - clinical use - & toxicity of 6 MP.
Well tolerated in general but occasionally - Nephrotoxicity - Ototoxicity - Thrombophlebitis - diffuse flushing='Red Man Syndrome'
Leukopenia - Neutropenia - Thrombocytopenia - Renal toxicity
- Estrogen receptor antagonist - Breast CA - increased endometrial CA risk
- inhibits HGPRT (pur. Syn.) - Luk - Lymph

25. What is the difference in receptor affinity of epinephrine at low doses? High doses?

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

26. What do Aminoglycosides require for uptake?
- Protamine
Oxygen
Cestode/tapeworm (e.g. - D. latum - Taenia species Except Cysticercosis
- Upper respiratory tract infections - pneumonias - STDs: Gram+ cocci (streptococcal infect in pts allergic to penicillin) - Mycoplasma - Legionella - Chlamydia - Neisseria

27. List the specific antidote for this toxin: Digitalis
Tricyclic antidepressant.
- Normalize K+ - Lidocaine - & Anti - dig Mab
Ibuprofen - Naproxen - and Indomethacin
Binds ergosterol - Disrupts fungal membranes

28. What Sulfonamides are used for simple UTIs?
Triple sulfas or SMZ
GI distress - Skin rash - and Seizures at high plasma levels
Inhibits reabsorption of uric acid.
- Methotrexate - 5 FU - 6 mercaptopurine

29. As an Anes you want to use a depolarizing neuromuscular blocking drug on your pt - What do you use
- Fluoroquinolones
Edrophonium
Succinylcholine
Reversible block of histamine H2 receptors

30. What antimicrobial class is Aztreonam syngergestic with?
edrophonium (extremely short acting anticholinesterase)
DOC in diagnosing and abolishing AV nodal arrhythmias
Aminoglycosides
- Deferoxamine

31. What is the MOA for Nystatin?
Binds ergosterol - Disrupts fungal membranes
These B-2 agonists cause respiratory smooth muscle to relax.
1. Pioglitazone 2. Rosiglitazone.
- Constant AMOUNT eliminated per unit time. - Etoh & ASA

32. Name several common Macrolides (3)
Nephrotoxicity (esp. with Cephalosporins) - Ototoxicity (esp. with Loop Diuretics)
Wide spectrum of systemic mycoses: Cryptococcus - Blastomyces - Coccidioides - Aspergillus - Histoplasma - Candida - Mucor
Giardiasis - Amoebic dysentery (E. histolytica) - Bacterial vaginitis (Gardnerella vaginalis) - Trichomonas
Erythromycin - Azithromycin - Clarithromycin

33. Name some common Tetracyclines (4)
Decreases synthesis of Mycolic Acid
Tetracycline - Doxycycline - Demeclocycline - Minocycline
Milk or Antacids - because divalent cations inhibit Tetracycline absorption in the gut
- Hydralazine - Procainamide - INH - phenytoin

34. Which receptors does phenylephrine act upon?
Blocks viral penetration/uncoating; may act to buffer the pH of the endosome
alpha -1 > alpha -2; used as a pupil dilator - vasoconstrictor - and for nasal decongestion
Triple sulfas or SMZ
Carbenicillin - Piperacillin - and Ticarcillin

35. Explain differences between full and partial agonists(2).
Pralidoxime regenerates active cholinesterase.
Edrophonium
Imipenem
- Act on same receptor - Full has greater efficacy

36. How does a noncompetitive antagonist effect an agonist?
- Alkalating agents+cisplatin - Doxorubicin+Dactinomycin - Bleomycin - Etoposide
- Shifts the curve down - reduces Vmax
Only in limited amounts
Activates cholinergic receptors on bladder and bowel smooth muscle - alleviating post - op and neurogenic ileus and urinary retention.

37. What is the MOA for Rifampin?
1) Chloramphenical = bacteriostatic 2) Erythromycin = bacteriostatic 3) Lincomycin = bacteriostatic 4)cLindamycin = bacteriostatic
Inhibits DNA dependent RNA polymerase
for RSV
- NaHCO3

38. Ca2+ channel blockers - site of action?
Foscarnet = pyroFosphate analog
Inhibits cell wall synthesis ( binds to PBP3). A monobactam
Cell membrane Ca2+ channels of cardiac sarcomere
HSV - VZV - EBV - Mucocutaneous and Genital Herpes Lesions - Prophylaxis in Immunocompromised pts

39. What are the clinical uses for 1st Generation Cephalosporins?
TCA
Decreased uptake or Increased transport out of cell
Gram + cocci - Proteus mirabilis - E. coli - Klebsiella pneumoniae (PEcK)
BM suppression (neutropenia - anemia) - Peripheral neuropathy

40. What reversal agent could a Anes give to reverse the effects of Atropine
Beta1 more than B2
Bethanechol - Neostigmine - physostigmine
hypertension - CHF - diabetic renal disease
- Chloramphenicol

41. How does angiotensin II affect NE release?
collecting ducts
impotence - asthma - CV effects (bradycardia - CHF - AV block) - CNS effects (sedation - sleep alterations)
It acts presynaptically to increase NE release.
- Shifts the curve down - reduces Vmax

42. What populations are Floroquinolones contraindicated in? Why?
Hypersensitivity reactions
- Glucocorticoid withdrawal
Pregnant women - Children; because animal studies show Damage to Cartilage
Receptors = D1=D2>beta>alpha - thus increasing heart rate (beta) and blood pressure (alpha vasoconstriction) while maintaining kidney perfusion (dopamine receptors)

43. Resistance mechanisms for Cephalosporins/Penicillins
Sulfonamides - Trimethoprim
Beta - lactamase cleavage of Beta - lactam ring
ACE inhibitor.
Beta lactams - inhibit cell wall synthesis - Bactericidal

44. How is Amphotericin B used clinically?
Wide spectrum of systemic mycoses: Cryptococcus - Blastomyces - Coccidioides - Aspergillus - Histoplasma - Candida - Mucor
first dose orthostatic hypotension - dizziness - headache
Cephalosporins
Gram + and Anerobes

45. Digoxin v. Digitoxin: bioavailability?
Digitoxin>95% Digoxin 75%
1. Pioglitazone 2. Rosiglitazone.
CMV - esp in Immunocompromised patients
- Methylene blue

46. What is the category of drug names ending in - navir (e.g. Saquinavir)
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
sedation - positive Coombs' test
- Normalize K+ - Lidocaine - & Anti - dig Mab
Protease inhibitor.

47. Which diuretics cause alkalosis?
Vd= (Amt. of drug in body/ Plasma drug conc.)
- Formaldehyde & formic acid - severe acidosis & retinal damage
Staphlococcus aureus
loop diuretics - thiazides

48. What is the receptor affinity and clinical use of isoproterenol?
It affects beta receptors equally and is used in AV heart block (rare).
Chronic (weeks or months)
Clavulanic acid
GI side effects. (Indomethacin is less toxic - more commonly used.)

49. Which drug(s) cause this reaction: Pulmonary fibrosis(3)?
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.
Beta -2 agonist.
- Bleomycin - amiodarone - busulfan
Protease inhibitor.

50. ACE inhibitors - clinical use?
hypertension - CHF - diabetic renal disease
fetal renal toxicity - hyperkalemia - Cough - Angioedema - Proteinuria - Taste changes - hypOtension - Pregnancy problems - Rash - Increased renin - Lower Angiotensin II (CAPTOPRIL)
Penicillin - V
- Shifts the curve down - reduces Vmax