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. Ibutilide - toxicity?
fetal renal toxicity - hyperkalemia - Cough - Angioedema - Proteinuria - Taste changes - hypOtension - Pregnancy problems - Rash - Increased renin - Lower Angiotensin II (CAPTOPRIL)
torsade de pointes
No. Atropine is used to reduce urgency in mild cystitis. So it would aggravate the urinary retention.
Give an antichloinesterase - neostigmine - edrophonium - etc

2. What is the only depolarizing neuromuscular blocking agent?
Benzathine penicillin G
Beta1 more than B2
Succinylcholine
IV vitamin K and fresh frozen plasma

3. Antiarrhythmic class IC- effects?
- Metronidazole - certain cephalosporins - procarbazine - sulfonylureas
When pts have Low CD4+ (< 500 cells/cubic mm) or a High Viral Load
Rifampin
NO AP duration effect. useful in V- tach that progresses to V- fib and in intractable SVT Last RESORT

4. Why is Cilastatin administered with Imipenem?
To inhibit renal Dihydropeptidase I and decrease Imipenem inactivation in the renal tubules
Acetylcholine esterase
Bacitracin - Vancomycin
- Alkalates DNA - CML - Pulmonary fibrosis hyperpigmentation

5. What are the side effects of Polymyxins?
Inhibt Assembly of new virus by Blocking Protease Enzyme
Epinephrine
Headache - flushing - dyspepsia - blue - green color vision.
Neurotoxicity - Acute renal tubular necrosis

6. What is the MOA for Ampicillin and Amoxicillin?
- Ammonium Chloride
Gram + cocci - Proteus mirabilis - E. coli - Klebsiella pneumoniae (PEcK)
Leukopenia - Neutropenia - Thrombocytopenia - Renal toxicity
Same as penicillin. Extended spectrum antibiotics

7. Foscarnet toxicity?
Nephrotoxicity
Penicillin - Ampicillin - Ticarcillin - Pipercillin - Imipenem - Aztreonam - Cephalosporins
vasodilator - increases cGMP to induce smooth muscle relaxation (arterioles>veins; afterload reduction)
Muscarinic antagonist; competatively blocks muscarinic receptors - preventing bronchoconstriction.

8. Furosemide - clinical use?
Beta Blockers
- Disulfram & also sulfonylureas - metronidazole
- Bleomycin - amiodarone - busulfan
edematous states (CHF - cirrhosis - nephrotic syndrome - pulm edema) - HTN - hypercalcemia

9. What are two indirect acting adrenergic agonists?
- Oral Contraceptives
amphetamine and ephedrine
Gemfibrozil - Clofibrate
Due to the presence of a bulkier R group

10. What are the side effects of Rifampin?
Minor hepatotoxicity - Drug interactions (activates P450)
Hypokalemic metabolic alkalosis - hyponatremia - hyperGlycemia - hyperLipidemia - hyperUricemia - hyperCalcemia - sulfa allergy.
- Triggers apoptosis - CLL - Hodgkin's in MOPP - Cushing - like syndrome
ACIDazolamide' causes acidosis

11. What are two Glitazones?
Pentavalent Antimony
- Cloazapine - carbamazapine - colchicine - PTU
- Cimetidine - ketoconazole - grapefruit juice - erythromycin - INH - sulfonamides
1. Pioglitazone 2. Rosiglitazone.

12. What is the MOA for Metronidazole?
fetal renal toxicity - hyperkalemia - Cough - Angioedema - Proteinuria - Taste changes - hypOtension - Pregnancy problems - Rash - Increased renin - Lower Angiotensin II (CAPTOPRIL)
Oral
Heparin catalyzes the activation of antithrombin III.
Forms toxic metabolites in the bacterial cell - Bactericidal

13. What is the category of drug names ending in - oxin (e.g. Digoxin)
Neutropenia
block voltage dependent L- type Ca2+ channels of cardiac and smooth muscle - decreasing contractility
- Methylene blue
Cardiac glycoside (inotropic agent).

14. How does NE modulate its own release? What other neurotransmitter has this same effect?
Due to the presence of a bulkier R group
AV nodal cells
1. Bleeding 2. Thrombocytopenia 3. Drug - drug interactions
NE acts presynaptically on alpha -2 receptors to inhibit its own release. ACh also acts presynaptically through M1 receptors to inhibit NE release.

15. Dobutamine used for the tx of shock acts on Which receptors
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.
Beta1 more than B2
- reduction - oxy - & hydrolysis - H2O sol. Polar product - P450
Hypersensitivity reactions

16. What is the MOA for the Azoles?
Inhibit Ergosterol synthesis
proarrhythmic
Chronic Hepatitis A and B - Kaposi's Sarcoma
1. Peptic ulcer 2. Gastritis 3. Esophageal reflux 4. Zollinger - Ellison syndrome

17. What antimuscarinic agent is used in asthma and COPD?
Ipratropium
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.
Protease inhibitor.
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)

18. What are common toxic side effects of Sulfonamides? (5)
It must be Phosphorylated by Viral Thymidine Kinase
new arrhythmias - hypotension
- Hypersensitivity reactions - Hemolysis - Nephrotoxicity (tubulointerstitial nephritis) - Kernicterus in infants Displace other drugs from albumin (e.g. - warfarin)
Inhibit steroid synthesis - used in the treatment of polycystic ovarian syndrome to prevent hirsutism.

19. List the specific antidote for this toxin: Lead
Inhalational general anesthetic.
Paranteral (IV - SC)
- EDTA - dimercaprol - succimer - & penicillamine
Binding to the presynaptic alpha 2 release modulating receptors

20. Thiazides - site of action?
AZT
Rare.
distal convoluted tubule (early)
The PTT.

21. Name several common Macrolides (3)
Similar to cyclosporine; binds to FK- binding protein - inhibiting secretion of IL-2 and other cytokines.
Carbenicillin - Piperacillin - and Ticarcillin
Epinephrine to treat anaphylaxis. Also useful if you have open angle glaucoma - asthma - or hypotension.
Erythromycin - Azithromycin - Clarithromycin

22. What are the clinical uses for Ticlopidine - Clopidogrel?
Acute coronary syndrome; coronary stenting. Decreases the incidence or recurrence of thrombotic stroke.
Dermatophytes (tinea - ringworm)
- NaHCO3
- Isoniazid

23. Name some common Sulfonamides (4)
Sulfamethoxazole (SMZ) - Sulfisoxazole - Triple sulfas - Sulfadiazine
Lovastatin - Pravastatin - Simvastatin - Atorvastatin
Same as penicillin. Act as narrow spectrum antibiotics
Polymyxin B - Polymyxin E

24. Describe first - order kinetics?
Mebendazole/Thiabendazole - Pyrantel Pamoate
Constant FRACTION eliminated per unit time.(exponential)
- Penicillamine
torsade de pointes - excessive Beta block

25. Which drug(s) cause this reaction: Photosensitivity(3)?
1.Gram - rods of the Urinary and GI tracts (including Pseudomonas) 2.Neisseria 3. Some Gram + organisms
Cardiac glycoside (inotropic agent).
- Tetracycline - amiodarone - sulfonamides
The PT.

26. What effect would atropine have on a patient with peptic ulcer disease?
- ED 50 is less than the Km (less than 50% of receptors)
Reversibly inhibit cyclooxygenase (COX I and COX II). Block prostaglandin synthesis.
Theoretically it could be used to block the cephalic phase of acid secretion (vagal stimulation).
Acetylates and irreversibly inhibits cyclooxygenase (COX I and COX II) to prevent the conversion of arachidonic acid to prostaglandins.

27. Name common Polymyxins
Polymyxin B - Polymyxin E
Beta antagonist.
Constant FRACTION eliminated per unit time.(exponential)
Depolymerizes microtubules - impairing leukocyte chemotaxis and degranulation.

28. How is Trimethoprim used clinically?
Tubocurarine - atracurium - mivacurium - pancuronium - vecuronium - rapacuronium
The PTT.
Useful in muscle paralysis during surgery or mechanical ventilation.
Used in combination therapy with SMZ to sequentially block folate synthesis

29. Beta Blockers - site of action?
Beta adrenergic receptors and Ca2+ channels (stimulatory)
1. Renal damage 2. Aplastic anemia 3. GI distress
YES
1. Aluminum hydroxide: constipation and hypophosphatemia 2. Magnesium hydroxide: diarrhea 3. Calcium carbonate: Hypercalcemia - rebound acid increase - All may cause hypokalemia

30. Name two organisms Vancomycin is commonly used for?
Saquinavir - Ritonavir - Indinavir - Nelfinavir
new arrhythmias - hypotension
Staphlococcus aureus and Clostridium difficile (pseudomembranous colitis)
sedation - positive Coombs' test

31. What are toxic side effects for Metronidazole?
- Shifts the curve down - reduces Vmax
amphetamine and ephedrine
Sulfamethoxazole (SMZ) - Sulfisoxazole - Triple sulfas - Sulfadiazine
Disulfiram - like reaction with EtOH - Headache

32. What should not be taken with Tetracyclines? / Why?
Headache - flushing - dyspepsia - blue - green color vision.
glaucoma - urinary alkalinization - metabolic alkalosis - altitude sickness
Gram + cocci - Haemophilus influenza - Enterobacter aerogenes - Neisseria species - P. mirabilis - E. coli - K. pneumoniae - Serratia marcescens ( HEN PEcKS )
Milk or Antacids - because divalent cations inhibit Tetracycline absorption in the gut

33. How are Sulfonamides employed clinically?
Gram + - Gram - - Norcardia - Chlamydia
Norepinephrine (Alpha1 -2 and beta 1)
reversible SLE- like syndrome
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

34. What organism is Imipenem/cilastatin the Drug of Choice for?
Enterobacter
all of them
decrease conduction velocity - increase ERP - increase PR interval
- N- acetylcystine

35. Does Warfarin have a long - medium - or short half life?
Long.
Selectively inhibit cyclooxygenase (COX) isoform 2 - Which is found in inflammatory cells nad mediates inflammation and pain; spares COX-1 Which helps maintain the gastric mucosa.
Benzathine penicillin G
all except the K+ sparing diuretics Spironolactone - Triamterene - Amiloride

36. While at a tail gait party - you bite into a sandwich that a yellow jacket is also enjoying. Knowing your allergy to this creature - What should you do?
Vibrio cholerae Acne Chlamydia Ureaplasma Urealyticum Mycoplasma pneumoniae Borrelia burgdorferi (Lyme's) Rickettsia Tularemia
Epinephrine to treat anaphylaxis. Also useful if you have open angle glaucoma - asthma - or hypotension.
- Sulfonamides - furosemide - methicillin - rifampin - NSAIDS (ex. ASA)
For serious - Gram + multidrug - resistant organisms

37. Verapamil has similar action to?
- aminoglycosides - loop diuretics - cisplatin
Aminoglycosides - Tetracyclines
Short.
Beta Blockers

38. Classes of antihypertensive drugs?
Neurotoxicity - Acute renal tubular necrosis
fetal renal toxicity - hyperkalemia
diuretics - sympathoplegics - vasodilators - ACE inhibitors - Angiotensin II receptor inhibitors
Those patients who are taking nitrates.

39. What enzyme is responsible for the degredation of Ach
vasodilator - increases cGMP to induce smooth muscle relaxation (arterioles>veins; afterload reduction)
Chronic gout.
Well tolerated in general but occasionally - Nephrotoxicity - Ototoxicity - Thrombophlebitis - diffuse flushing='Red Man Syndrome'
Acetylcholine esterase

40. MOA: Disrupt fungal cell membranes
- Oxalic acid - Acidosis & nephrotoxicity
- DNA intercalator - Hodgkin's - myeloma - sarcoma - and solid tumors - Cardiotoxicity & alopecia
Amphotericin B - Nystatin - Fluconazole/azoles
hyperchloremic metabolic acidosis - neuropathy - NH3 toxicity - sulfa allergy

41. Acetazolamide - site of action?
1. Renal damage 2. Aplastic anemia 3. GI distress
Used in combination therapy with SMZ to sequentially block folate synthesis
proximal convoluted tubule
Activates antithrombin III

42. Digoxin v. Digitoxin: excretion?
all of them
physostigmine
Teratogenic - Carcinogenic - Confusion - Headaches
Digoxin=urinary Digitoxin=biliary

43. Adverse effects of Guanethidine?
It affects beta receptors equally and is used in AV heart block (rare).
- Alkalates DNA - CML - Pulmonary fibrosis hyperpigmentation
orthostatic and exercise hypotension - sexual dysfunction - diarrhea
Dopamine; causes its release from intact nerve terminals

44. Name some common Tetracyclines (4)
Inhibits cell wall mucopeptide formation - Bactericidal
fetal renal damage - hyperkalemia - Cough - Angioedema - Proteinuria - Taste changes - hypOtension - Pregnancy problems - Rash - Increased renin - Lower Angiotensin II (CAPTOPRIL)
Aminoglycosides - Tetracyclines
Tetracycline - Doxycycline - Demeclocycline - Minocycline

45. Resistance mechanisms for Chloramphenicol
Blastomyces - Coccidioides - Histoplasma - C. albicans; Hypercortisolism
Modification via Acetylation
Beta - lactam antibiotics
Blocks translocation - binds to the 23S rRNA of the 50S subunit - Bacteriostatic

46. Which drug(s) cause this reaction: Adrenocortical Insufficiency
Slow - limited by half lives of clotting factors
- Glucocorticoid withdrawal
ARF - shock - drug overdose - decrease intracranial/intraocular pressure
Hydralazine and Minoxidil

47. Mannitol - contraindications?
- Weak Acids>Alkinalize urine(CO3) to remove more - Weak bases>acidify urine to remove more
- Glucagon
Reserpine inhibits dopamine transport into vesicles - attenuating its conversion to NE by dopamine beta - hydroxylase.
anuria - CHF

48. What are three unwanted effects of Mifepristone?
1. Aluminum hydroxide: constipation and hypophosphatemia 2. Magnesium hydroxide: diarrhea 3. Calcium carbonate: Hypercalcemia - rebound acid increase - All may cause hypokalemia
1. Heavy bleeding 2. GI effects (n/v - anorexia) 3. Abdominal pain
scopolamine
osmotic diuretic - increase tubular fluid osmolarity - thereby increasing urine flow

49. List the specific antidote for this toxin: Salicylates
severe orthostatic hypotension - blurred vision - constipation - sexual dysfunction
- Alkalinize urine & dialysis
Ciprofloxacin - Norfloxacin - Ofloxacin - Grepafloxacin - Enoxacin - Nalidixic acid
1. Mycobacterium tuberculosis 2. Delays resistance to Dapsone When used of Leprosy 3. Used in combination with other drugs

50. Norepi feedbacks and inhibits the presynaptic receptor by What mechanism
With supplemental Folic Acid
Binding to the presynaptic alpha 2 release modulating receptors
Reversible block of histamine H2 receptors
1. Peptic ulcer 2. Gastritis 3. Esophageal reflux 4. Zollinger - Ellison syndrome