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. Antimicrobial prophylaxis for a history of recurrent UTIs
Bind cell membrane - disrupt osmotic properties - Are Cationc - Basic and act as detergents
Butyrophenone (neuroleptic).
TMP- SMZ
decrease AP duration - affects ischemic or depolarized Purkinje and ventricular system

2. What are the products and their toxicities of the metabolism of Ethylene Glycol by / alcohol dehydrogenase?
fetal renal toxicity - hyperkalemia
No. Atropine is used to reduce urgency in mild cystitis. So it would aggravate the urinary retention.
1) Hypersensitivity reactions 2) Increased nephrotoxicity of Aminoglycosides 3) Disulfiram - like reaction with ethanol (those with a methylthiotetrazole group - e.g. - cefamandole)
- Oxalic acid - Acidosis & nephrotoxicity

3. What is the effect of norepinephrine on bp and pulse pressure?
- Bleomycin - amiodarone - busulfan
very short acting
- A57Blue lines in gingiva & long bones - Encephalopathy & Foot drop - Abdominal colic / - Sideroblastic anemia
Increases mean - systolic - and diastolic bp - while there is little change in pulse pressure.

4. How is Ribavirin used clinically?
for RSV
Inhibit intestinal bursh border Alpha - glucosidases; delayed hydrolysis of sugars and absorption of sugars leading to decresed postprandial hyperglycemia.
cyanide toxicity (releases CN)
They inhibit reuptake of NE at the nerve terminal (as does cocaine).

5. List the specific antidote for this toxin: Warfarin
Nucleosides
Inhibits cell wall mucopeptide formation - Bactericidal
- Vitamin K & fresh frozen plasma
1. Phospholipase A2 is prevented from releasing arachidonic acid 2. Decreases protein synthesis thus lowering amount of Cyclooxygenase enzymes

6. What antimuscarinic agent is used in asthma and COPD?
VACUUM your Bed Room'
Pentavalent Antimony
Ipratropium
- Alkalating agent - testicular - bladder - ovary -& lung - Nephrotoxicity & CN VIII damage.

7. Name the steps in drug approval(4)?
Staphlococcus aureus and Clostridium difficile (pseudomembranous colitis)
Systemic mycoses
The PTT.
- Phase I (clinical tests) - Phase II - Phase III - PhaseIV (surveillance)

8. What are three clinical uses of the NSAIDs?
1. Antipyretic 2. Analgesic 3. Anti - inflammatory
cardiac depression - peripheral edema - flushing - dizziness - constipation
No - warfarin - unlike heparin - can cross the placenta.
Oxygen

9. What microorganisms is Aztreonam not effective against?
- Shifts the curve to the right - increases Km
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.
Gram + and Anerobes
- Methylene blue

10. Aztreonam is not usually...
Md= (CpxCL)/F Cp= plas. Conc. CL=clear. F=bioaval.
Theoretically it could be used to block the cephalic phase of acid secretion (vagal stimulation).
toxic
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. Name three Antiarrhythmic drugs in class IV.
No - hemicholinum block the uptake of Choline and thus Ach synthesis
Cestode/tapeworm (e.g. - D. latum - Taenia species Except Cysticercosis
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.
Verapamil - Diltiazem - Bepridil

12. What class of drug is echothiophate? What is its indication?
anticholinesterase glaucoma
Binding to the presynaptic alpha 2 release modulating receptors
Minor hepatotoxicity - Drug interactions (activates P450)
- Weak Acids>Alkinalize urine(CO3) to remove more - Weak bases>acidify urine to remove more

13. Which cancer drugs work at the level of mRNA(2)?
new arrhythmias - hypotension
Quinolones
Ld= (CpxVd)/F Cp=plasma conc. F= Bioaval.
- Steroids - Tamoxifen

14. Furosemide - toxicity? (OH DANG)
Stimulates beta adrenergic receptors
effective in torsade de pointes and digoxin toxicity
Ototoxicity - Hypokalemia - Dehydration - Allergy (sulfa) - Nephritis (interstitial) - Gout
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.

15. How does NE modulate its own release? What other neurotransmitter has this same effect?
Hormone synthesis inhibition (Gynecomastia) - Liver dysfunction (Inhibits CYP450) - Fever - Chills
NE acts presynaptically on alpha -2 receptors to inhibit its own release. ACh also acts presynaptically through M1 receptors to inhibit NE release.
- Tetracycline
- Normalize K+ - Lidocaine - & Anti - dig Mab

16. What are the side effects of Rifampin?
- Methotrexate - 5 FU - 6 mercaptopurine
Ganciclovir is more toxic to host enzymes
Minor hepatotoxicity - Drug interactions (activates P450)
Polymyxin B - Polymyxin E

17. ADH antagonists - site of action?
collecting ducts
sedation - depression - nasal stuffiness - diarrhea
Md= (CpxCL)/F Cp= plas. Conc. CL=clear. F=bioaval.
Nucleosides

18. Name common Polymyxins
for RSV
Polymyxin B - Polymyxin E
They activate the ciliary muscle of the eye (open angle) and pupillary sphincter (narrow angle).
Chronic anticoagulation.

19. Which of epi - norepi - or isoproterenol results in bradycardia?
Foscarnet = pyroFosphate analog
cinchonism: HA - tinnitus - thrombocytopenia - torsade de pointes due to increased QT interval
hypertrichosis - pericardial effusion - reflex tachycardia - angina - salt retention
Norepinephrine

20. Foscarnet toxicity?
Cimetidine is a potent inhibitor of P450; it also has an antiandrogenic effect and decreases renal excretion of creatinine. Other H2 blockers are relatively free of these effects.
- Clindamycin
Methicillin - Nafcillin - and Dicloxacillin
Nephrotoxicity

21. What are four H2 Blockers?
Binds Ergosterol - forms Membrane Pores that Disrupt Homeostatis
1. Cimetadine 2. Ranitidine 3. Famotidine 4. Nizatidine
Captopril - Enalapril - Lisinopril
None. No - because atropine would block the postganglionic muscarinic receptors involved in sweat gland stimulation.

22. List the mechanism - clinical use - & toxicity of Bleomycin.
- DNA intercalator - testicular & lymphomas - Pulmonary fibrosis mild myelosuppression.
Theoretically it could be used to block the cephalic phase of acid secretion (vagal stimulation).
edematous states (CHF - cirrhosis - nephrotic syndrome - pulm edema) - HTN - hypercalcemia
Penicillin - G

23. Where does Griseofulvin deposit?
1. Streptokinase 2. Urokinase 3. tPA (alteplase) - APSAC (anistreplase)
Rifampin
Keratin containing tissues - e.g. - nails
Chronic (weeks or months)

24. Which drug(s) cause this reaction: Hot flashes?
Amphotericin B - Nystatin - Fluconazole/azoles
Chronic anticoagulation.
CL= (rate of elimination of drug/ Plasma drug conc.)
- Tamoxifen

25. How is Acyclovir used clinically?
Disulfiram - like reaction with EtOH - Headache
depresses ectopic pacemakers - especially in digoxin toxicity
HSV - VZV - EBV - Mucocutaneous and Genital Herpes Lesions - Prophylaxis in Immunocompromised pts
Extended spectrum penicillin: certain Gram + bacteria and Gram - rods

26. What are two conditions in Which COX-2 inhibitors might be used?
Rheumatoid and osteoarthritis.
These B-2 agonists cause respiratory smooth muscle to relax.
Close K+ channels in Beta - cell membrane leading to cell depolarization causing insulin release triggered by increase in Calcium ion influx.
Neostigmine - pyridostigmine edrophonium - physostigmine echothiophate

27. Which antimicrobials inhibit protein synthesis at the 50S subunit? (4)
1) Chloramphenical = bacteriostatic 2) Erythromycin = bacteriostatic 3) Lincomycin = bacteriostatic 4)cLindamycin = bacteriostatic
TMP- SMZ (DOC) - aerosolized pentamidine
Erythromycin - Azithromycin - Clarithromycin
- Hydralazine - Procainamide - INH - phenytoin

28. What is the mechanism of action of Sildenafil (Viagra)?
Succinylcholine
Sotalol - Ibutilide - Bretylium - Amiodarone
Beta 2 agonist; used as a long - acting agent for prophylaxis. Adverse effects are tremor and arrhythmia.
Inhibits cGMP phosphodiesterase - casuing increased cGMP - smooth muscle relaxation in the corpus cavernosum - increased blood flow - and penile erection.

29. How are Sulfonamides employed clinically?
check PFTs - LFTs - and TFTs
Gram + - Gram - - Norcardia - Chlamydia
Neomycin
post MI and digitalis induced arrhythmias

30. What is the mechanism of action of Clomiphene?
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.
Acute (hours)
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
Beta -2 agonist.

31. Side effects of Isoniazid (INH)?
Pentamidine
Milk or Antacids - because divalent cations inhibit Tetracycline absorption in the gut
Hemolysis (if G6PD deficient) - Neurotoxicity - Hepatotoxicity - SLE- like syndrome
Mycobacterium tuberculosis - the only agent used as solo prophylaxis against TB

32. Which H2 Blocker has the most toxic effects and What are they?
Cimetidine is a potent inhibitor of P450; it also has an antiandrogenic effect and decreases renal excretion of creatinine. Other H2 blockers are relatively free of these effects.
1.Gram - rods of the Urinary and GI tracts (including Pseudomonas) 2.Neisseria 3. Some Gram + organisms
Premature infants - because they lack UDP- glucuronyl transferase
anuria - CHF

33. 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

34. What is the mechanism of Leuprolide?
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
- Glucocorticoid withdrawal
Rifampin
1. Meningococcal carrier state 2. Chemoprophylaxis in contacts of children with H. influenzae type B

35. What is the formula for Volume of distribution (Vd)
Penicillin - G
Indomethacin is used to close a patent ductus arteriosus.
Vd= (Amt. of drug in body/ Plasma drug conc.)
Inhibits cell wall mucopeptide formation - Bactericidal

36. What is the category - desired effect - and possible mechanism of Theophylline in treating Asthma?
Increased systolic and pulse pressure - decreased diastolic pressure - and little change in mean pressure.
Methylzanthine; desired effect is bronchodilation - may cause bronchodilation by inhibiting phosphodiesterase - enzyme involved in degrading cAMP (controversial).
When pts have Low CD4+ (< 500 cells/cubic mm) or a High Viral Load
- Topo II inhibitor(GII specific) - Oat cell of Lung & prostate - & testicular - Myelosuppression & GI irritation.

37. Why does NE result in bradycardia?
NE increases bp - Which stimulates baroreceptors in the carotid sinus and the aorta. The CNS signals through vagal stimulation to decrease heart rate.
sedation - depression - nasal stuffiness - diarrhea
H2 antagonist
- S- phase anti - metabolite folate analogue - Luk - Lymp - sarc - RA - & psoriasis / - Reversible myelosuppression

38. What is the lab value used to monitor the effectiveness of Warfarin therapy?
The PT.
impotence - asthma - CV effects (bradycardia - CHF - AV block) - CNS effects (sedation - sleep alterations)
Abortifacient.
They activate the ciliary muscle of the eye (open angle) and pupillary sphincter (narrow angle).

39. Which cancer drugs effect nuclear DNA (4)?
proarrhythmic
GI upset
Indirect agonist - uptake inhibitor
- Alkalating agents+cisplatin - Doxorubicin+Dactinomycin - Bleomycin - Etoposide

40. Which drug(s) cause this reaction: Cutaneous flushing (4)?
Minor hepatotoxicity - Drug interactions (activates P450)
- Niacin - Ca++ channel blockers - adenosine - vancomycin
Flutamide is a nonsteroidal competitive inhibitor of androgens at the testosterone receptor - used in prostate carcinoma.
block voltage dependent L- type Ca2+ channels of cardiac and smooth muscle - decreasing contractility

41. What is the mechanism of action of Mifepristone (RU486)?
It affects beta receptors equally and is used in AV heart block (rare).
first dose orthostatic hypotension - dizziness - headache
Competitive inibitor of progestins at progesterone receptors.
Bacitracin - Vancomycin

42. Thiazides - site of action?
Diarrhea - Urination - Miosis - Bronchospasm - Bradycardia - Excitation of skeletal muscle and CNS - Lacrimation - Sweating - and Salivation = DUMBBELS; also abdominal cramping
acts at the proximal convoluted tubule to inhibit carbonic anhydrase. Causes self - limited sodium bicarb diuresis and reduction of total body bicarb stores.
distal convoluted tubule (early)
Misoprostol is contraindicated in women of childbearing potential because it is an abortifacient.

43. Which drug(s) cause this reaction: SLE- like syndrome?
- Phase I (clinical tests) - Phase II - Phase III - PhaseIV (surveillance)
hyperkalemia - endocrine effects (gynecomastia - anti - androgen)
- Hydralazine - Procainamide - INH - phenytoin
- EDTA - dimercaprol - succimer - & penicillamine

44. Which drug(s) cause this reaction: Agranulocytosis (3)?
Carbachol - pilocarpine - physostigmine - echothiophate
Ipratropium
- Cloazapine - carbamazapine - colchicine - PTU
Competitive inibitor of progestins at progesterone receptors.

45. How does a competitive antagonist effect an agonist?
decrease AP duration - affects ischemic or depolarized Purkinje and ventricular system
Ca2+ (Loops Lose calcium)
- Shifts the curve to the right - increases Km
Delirium - Tremor - Nephrotoxicity

46. Adverse effects of Loop Diuretics?
Md= (CpxCL)/F Cp= plas. Conc. CL=clear. F=bioaval.
Fluconazole - Ketoconazole - Clotrimazole - Miconazole - Itraconazole
K+ wasting - metabolic alkalosis - hypotension - ototoxicity
Extended spectrum penicillin: certain Gram + bacteria and Gram - rods

47. What is the category of drug names ending in - oxin (e.g. Digoxin)
Hemolytic anemia
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
NE increases bp - Which stimulates baroreceptors in the carotid sinus and the aorta. The CNS signals through vagal stimulation to decrease heart rate.
Cardiac glycoside (inotropic agent).

48. Antiarrhythmic class II- toxicity?
hyperkalemia - endocrine effects (gynecomastia - anti - androgen)
Interferes with microtubule function - disrupts mitosis - inhibits growth
GI distress - Tooth discoloration and Inhibition of bone growth in children - Fanconi's syndrome - Photosensitivity
impotence - exacerbation of asthma - CV effects - CNS effects - may mask hypoclycemia

49. What is the category and mechanism of action of Zileuton in Asthma treatment?
Antileukotriene; blocks synthesis by lipoxygenase.
CMV - esp in Immunocompromised patients
Blocks viral penetration/uncoating; may act to buffer the pH of the endosome
Inhibits Viral DNA polymerase

50. List the mechanism - clinical use - & toxicity of Methotrexate.
- NaHCO3
- S- phase anti - metabolite folate analogue - Luk - Lymp - sarc - RA - & psoriasis / - Reversible myelosuppression
Acts as a wide spectrum carbapenem
- Ethosuxamide - sulfonamides - lamotrigine