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. List the mechanism - clinical use - & toxicity of Doxorubicin.

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

2. Isopoterenol was given to a patient with a developing AV block - why?
Stimulates beta adrenergic receptors
Treatment of hypertension - especially with renal disease (lowers bp centrally - so flow is maintained to kidney).
reversible SLE- like syndrome
Megaloblastic anemia - Leukopenia - Granulocytopenia

3. Which diuretics decrease urine Ca2+?
acts at the proximal convoluted tubule to inhibit carbonic anhydrase. Causes self - limited sodium bicarb diuresis and reduction of total body bicarb stores.
It affects beta receptors equally and is used in AV heart block (rare).
Methylxanthine.
thiazides - amiloride

4. List the mechanism - clinical use - & toxicity of Methotrexate.
- Chloramphenicol - benzene - NSAIDS - PTU - phenytoin
Receptors = D1=D2>beta>alpha - thus increasing heart rate (beta) and blood pressure (alpha vasoconstriction) while maintaining kidney perfusion (dopamine receptors)
Topical and Oral - for Oral Candidiasis (Thrush)
- S- phase anti - metabolite folate analogue - Luk - Lymp - sarc - RA - & psoriasis / - Reversible myelosuppression

5. When is HIV therapy initiated?
When pts have Low CD4+ (< 500 cells/cubic mm) or a High Viral Load
Protamine sulfate
fetal renal toxicity - hyperkalemia - Cough - Angioedema - Proteinuria - Taste changes - hypOtension - Pregnancy problems - Rash - Increased renin - Lower Angiotensin II (CAPTOPRIL)
Sulfonamide Loop Diuretic. Inhibits ion co - transport system of thick ascending loop. Abolishes hypertonicity of the medulla - thereby preventing concentration of the urine.

6. What are the nondepolarizing neuromuscular blocking drugs?
Reserpine inhibits dopamine transport into vesicles - attenuating its conversion to NE by dopamine beta - hydroxylase.
- ED 50 is less than the Km (less than 50% of receptors)
Tubocurarine - atracurium - mivacurium - pancuronium - vecuronium - rapacuronium
1. Addison's disease 2. Inflammation 3. Immune suppression 4. Asthma

7. What type of gout is treated with Probenacid?
Does not cross
increase AP duration - increase ERP - increase QT interval - for use When other arrhythmics fail
Chronic gout.
Bethanechol - Neostigmine - physostigmine

8. What are five advantages of Oral Contraceptives (synthetic progestins - estrogen)?
Tendonitis and Tendon rupture
BM suppression (neutropenia - anemia) - Peripheral neuropathy
1. Antiandrogen 2. Nausea 3. Vomiting
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

9. What are common side effects of Protease Inhibitors?
TMP- SMZ (DOC) - aerosolized pentamidine
Staphlococcus aureus and Clostridium difficile (pseudomembranous colitis)
cardiac muscle: Verapamil>Diltiazem>Nifedipine
GI intolerance (nausea - diarrhea) - Hyperglycemia - Lipid abnormalities - Thrombocytopenia (Indinavir)

10. What are four unwanted effects of Clomiphene use?
Topical and Oral - for Oral Candidiasis (Thrush)
Sucralfate cannot work in the presence of antacids or H2 blockers because it requires an acidic environment to polymerize.
1. Hot flashes 2. Ovarian enlargement 3. Multiple simultaneous pregnancies 4. Visual disturbances
NE acts presynaptically on alpha -2 receptors to inhibit its own release. ACh also acts presynaptically through M1 receptors to inhibit NE release.

11. Where does Griseofulvin deposit?
Sulfonamide Loop Diuretic. Inhibits ion co - transport system of thick ascending loop. Abolishes hypertonicity of the medulla - thereby preventing concentration of the urine.
Keratin containing tissues - e.g. - nails
Hemicholinium inhibits the transport of choline into the nerve - thus inhibiting formation of ACh.
- Halothane - Valproic acid - acetaminophen - Amantia phalloides

12. What should not be taken with Tetracyclines? / Why?
block voltage dependent L- type Ca2+ channels of cardiac and smooth muscle - decreasing contractility
Treatment of hypertension - especially with renal disease (lowers bp centrally - so flow is maintained to kidney).
Pseudomonas species and Gram - rods
Milk or Antacids - because divalent cations inhibit Tetracycline absorption in the gut

13. Decrease Digitoxin dose in renal failure?
Bactericidal for: Gram + rod and cocci - Gram - cocci - and Spirochetes
edematous states (CHF - cirrhosis - nephrotic syndrome - pulm edema) - HTN - hypercalcemia
NO
Resistant Gram - infections

14. What is combined with Ampicillin - Amoxicillin - Carbenicillin - Piperacillin - and Ticarcillin to enhance their spectrum?
Beta Blockers
Clavulanic acid
Muscarinic antagonist; competatively blocks muscarinic receptors - preventing bronchoconstriction.
- Metronidazole - certain cephalosporins - procarbazine - sulfonylureas

15. Why would dopamine be useful in treating shock?
- ACE inhibitors (Losartan>no cough)
competitive inhibirot of aldosterone in the cortical collecting tubule
vascular sm. Mus.: Nifedipine>Diltiazem>Verapamil
Receptors = D1=D2>beta>alpha - thus increasing heart rate (beta) and blood pressure (alpha vasoconstriction) while maintaining kidney perfusion (dopamine receptors)

16. Nifedipine has similar action to?
Nitrates
Acetylates and irreversibly inhibits cyclooxygenase (COX I and COX II) to prevent the conversion of arachidonic acid to prostaglandins.
Beta Blockers
dry mouth - sedation - severe rebound hypertension

17. List the mechanism - clinical use - & toxicity of Bleomycin.
- DNA intercalator - testicular & lymphomas - Pulmonary fibrosis mild myelosuppression.
Babiturate.
- Haloperidol - chlorpromazine - reserpine - MPTP
propanolol - esmolol - metoprolol - atenolol - timolol

18. How do you treat coma in the ER (4)?
Warfarin interferes with the normal synthesis and gamma - carboxylation of vitamin K- dependent clotting factors II - VII - IX - and X - Protein C and S via vitamin K antagonism.
- Airway - Breathing - Circulation - Dextrose (thiamine & narcan) - ABCD
It must be Phosphorylated by Viral Thymidine Kinase
1. Aluminum hydroxide: constipation and hypophosphatemia 2. Magnesium hydroxide: diarrhea 3. Calcium carbonate: Hypercalcemia - rebound acid increase - All may cause hypokalemia

19. What are the products and their toxicities of the metabolism of Ethylene Glycol by / alcohol dehydrogenase?
- Clindamycin
- polymyxins
for RSV
- Oxalic acid - Acidosis & nephrotoxicity

20. MOA of Succinylcholine
Beta lactams - inhibit cell wall synthesis - Bactericidal
Prevents the release of Ca from SR of skeletal muscle
Finasteride inhibits 5 Alpha - reductase - this decreases the conversion of testosterone to dihydrotestosterone - useful in BPH
- Shifts the curve down - reduces Vmax

21. Antiarrhythmic class IB- toxicity?
Alpha -1 antagonist
Blocks translocation - binds to the 23S rRNA of the 50S subunit - Bacteriostatic
local anesthetic. CNS stimulation or depression. CV depression.
Bacitracin - Vancomycin

22. Name some common Tetracyclines (4)
Sulfonylureas are oral hypoglycemic agents - they are used to stimulate release of endogenous insulin in NIDDM (type -2).
Tetracycline - Doxycycline - Demeclocycline - Minocycline
- Alkalating agents+cisplatin - Doxorubicin+Dactinomycin - Bleomycin - Etoposide
Onchocerciasis ('river blindness'-- rIVER- mectin)

23. Resistance mechanisms for Tetracycline
GI distress - Skin rash - and Seizures at high plasma levels
Reversible block of histamine H2 receptors
Decreased uptake or Increased transport out of cell
1. Kidney transplantation 2. Autoimmune disorders (including glomerulonephritis and hemolytic anemia)

24. What antimicrobial class is Aztreonam syngergestic with?
- S- phase anti - metabolite folate analogue - Luk - Lymp - sarc - RA - & psoriasis / - Reversible myelosuppression
severe hypertension - CHF
Acute (hours)
Aminoglycosides

25. List the specific antidote for this toxin: Methanol & Ethylene glycol
- Tetracycline
- Cloazapine - carbamazapine - colchicine - PTU
- Ethanol - dialysis - & fomepizole
Delirium - Tremor - Nephrotoxicity

26. Mnemonic for Foscarnet?
Foscarnet = pyroFosphate analog
Post - op and neurogenic ileus and urinary retention - myasthenia gravis - and reversal of neuromuscular junction blockade (post - op) through anticholinesterase activity.
Immediate anticoagulation for PE - stroke - angina - MI - DVT.
Protamine Sulfate is used for rapid reversal of heparinization (positively charged molecule that binds to negatively charged heparin).

27. What are two mechanisms of action of Propythiouracil?
1. Bleeding 2. Thrombocytopenia 3. Drug - drug interactions
Hemicholinium inhibits the transport of choline into the nerve - thus inhibiting formation of ACh.
Inhibits organification and coupling of thyroid hormone synthesis. Also decreases peripheral conversion of T4 to T3.
- polymyxins

28. Antiarrhythmic class II- mechanism?
blocking the beta adrenergic receptor leads to decreased cAMP - and decreased Ca2+ flux
Tricyclic antidepressant.
Imipenem
Antiprotozoal: Giardia - Entamoeba - Trichomonas - Gardnerella vaginalis Anaerobes: Bacteroides - Clostridium

29. ________ ae not resistant to penicillinase - - but they are less susceptible than the other Beta lactams
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.
GI distress - Skin rash - and Seizures at high plasma levels
Cephalosporins
Overdose produces hepatic necrosis; acetaminophen metablolite depletes glutathione and forms toxic tissue adducts in liver.

30. What are three toxicities of Propylthiouracil?
1. Skin rash 2. Agranulocytosis (rare) 3. Aplastic anemia
Mg = Must go to the bathroom.
Methylzanthine; desired effect is bronchodilation - may cause bronchodilation by inhibiting phosphodiesterase - enzyme involved in degrading cAMP (controversial).
GI intolerance (nausea - diarrhea) - Hyperglycemia - Lipid abnormalities - Thrombocytopenia (Indinavir)

31. Name several common Macrolides (3)
Acute (hours)
Erythromycin - Azithromycin - Clarithromycin
For serious - Gram + multidrug - resistant organisms
Heparin catalyzes the activation of antithrombin III.

32. Cocaine shares is mechanism of action with What antidepressant
Enterobacter
Cyclooxygenases (COX I - COX II).
TCA
GET on the Metro

33. What are four H2 Blockers?
1. In liver - increases storage of glucose as glycogen. 2. In muscle - stimulates glycogen and protein synthesis - and K+ uptake. 3. In adipose tissue - facilitates triglyceride storage.
Methylzanthine; desired effect is bronchodilation - may cause bronchodilation by inhibiting phosphodiesterase - enzyme involved in degrading cAMP (controversial).
proximal convoluted tubule
1. Cimetadine 2. Ranitidine 3. Famotidine 4. Nizatidine

34. What is Ketoconazole specifically used for?
Protease Inhibitors and Reverse Transcriptase Inhibitors
Recurrent UTIs - Shigella - Salmonella - Pneumocystis carinii pneumonia
competitive inhibirot of aldosterone in the cortical collecting tubule
Blastomyces - Coccidioides - Histoplasma - C. albicans; Hypercortisolism

35. Specifically - How does Foscarnet inhibit viral DNA pol?
Treatment of infertility.
Blocks translocation - binds to the 23S rRNA of the 50S subunit - Bacteriostatic
severe orthostatic hypotension - blurred vision - constipation - sexual dysfunction
Binds to the Pyrophosphate Binding Site of the enzyme

36. Why are albuterol and terbutaline effective in tx of acute asthmatic attacks?
Rifampin (DOC) - minocycline
1. Phospholipase A2 is prevented from releasing arachidonic acid 2. Decreases protein synthesis thus lowering amount of Cyclooxygenase enzymes
These B-2 agonists cause respiratory smooth muscle to relax.
Albuterol - tertbutaline

37. What are the products and their toxicities of the metabolism of ethanol by / alcohol dehydrogenase?
- Acetaldehyde - Nausea - vomiting - headache - & hypotension
- inhibits HGPRT (pur. Syn.) - Luk - Lymph
hyperchloremic metabolic acidosis - neuropathy - NH3 toxicity - sulfa allergy
Aminoglycosides - Tetracyclines

38. What is the clinical use for Clomiphene?
Dopamine; causes its release from intact nerve terminals
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.
Treatment of infertility.
IV vitamin K and fresh frozen plasma

39. Which RT inhibitor causes Megaloblastic Anemia?
Severe Gram - rod infections.
Useful in muscle paralysis during surgery or mechanical ventilation.
Phosphorylation by a Viral Kinase
AZT

40. What are three unwanted effects of Mifepristone?
- Tetracycline - amiodarone - sulfonamides
1. Heavy bleeding 2. GI effects (n/v - anorexia) 3. Abdominal pain
nausea - headache - lupus - like syndrome - reflex tachycardia - angina - salt retention
AV nodal cells

41. What is the mechanism of action of Aspirin?
- Antipsychotics
Hypersensitivity reactions
GI disturbances.
Acetylates and irreversibly inhibits cyclooxygenase (COX I and COX II) to prevent the conversion of arachidonic acid to prostaglandins.

42. For Heparin What is the Site of action
Beta 2 agonist; desired effect is the relaxation of bronchial smooth muscle (Beta 2). Use during acute exacerbation.
Blood
reversible SLE- like syndrome
- Corticosteroids - heparin

43. MOA: Block cell wall synthesis by inhib. Peptidoglycan cross - linking (7)
Penicillin - Ampicillin - Ticarcillin - Pipercillin - Imipenem - Aztreonam - Cephalosporins
- Antipsychotics
- Penicillin
Vd= (Amt. of drug in body/ Plasma drug conc.)

44. What is the category - mechanism of action - and particular use of beclomethasone and prednisone in Asthma treatment?
- Phase I (clinical tests) - Phase II - Phase III - PhaseIV (surveillance)
Corticosteroids; prevent production of leukotrienes from arachodonic acid by blocking phospholipase A2. Drugs of choice in a patient with status asthmaticus (in combination with albuterol.)
Mebendazole/Thiabendazole - Pyrantel Pamoate
DHPG (dihydroxy-2- propoxymethyl guanine)

45. Hydrochlorothiazide - mechanism?
Inhibits NaCl reabsorption in the early distal tubule. Decreases Ca2+ excretion.
-100% oxygen - hyperbaric
Binds to the Pyrophosphate Binding Site of the enzyme
Misoprostol is contraindicated in women of childbearing potential because it is an abortifacient.

46. Which drug(s) cause this reaction: Gingival hyperplasia?
distal convoluted tubule (early)
AZT - to reduce risk of Fetal Transmission
- Phenytoin
1. Bleeding 2. Thrombocytopenia 3. Drug - drug interactions

47. What is the formula for Clearance (CL)
Nephrotoxicity
- S- phase anti - metabolite Pyr analogue - Colon - solid tumors - & BCC/ - Irreversible myelosuppression
CL= (rate of elimination of drug/ Plasma drug conc.)
Interstitial nephritis

48. Which of these three drugs will cause a reflex bradycardia in your pt (Norepi - Epi - or Isoporterenol)
Mycobacterium tuberculosis - the only agent used as solo prophylaxis against TB
Norepinephrine
Rare.
For serious - Gram + multidrug - resistant organisms

49. What is a common drug interaction associated with Griseofulvin?
reversible SLE- like syndrome
Systemic mycoses
Binds ergosterol - Disrupts fungal membranes
Increases coumadin metabolism

50. What is the mechanism of action of Probenacid used to treat chronic gout?
Inhibits reabsorption of uric acid.
Tricyclic antidepressant.
pulmonary edema - dehydration
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