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USMLE Step 1 Pharmacology

Subjects : health-sciences, usmle-step-1

Instructions:

Answer 50 questions in 15 minutes.
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Match each statement with the correct term.
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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 category - desired effect - and period of use of albuterol in the treatment of Asthma?
Beta 2 agonist; desired effect is the relaxation of bronchial smooth muscle (Beta 2). Use during acute exacerbation.
bradycardia - AV block - CHF
Blastomyces - Coccidioides - Histoplasma - C. albicans; Hypercortisolism
- DNA intercalator - testicular & lymphomas - Pulmonary fibrosis mild myelosuppression.

2. Resistance mechanisms for Macrolides

3. List the mechanism - clinical use - & toxicity of Bleomycin.
cardiac muscle: Verapamil>Diltiazem>Nifedipine
GI side effects. (Indomethacin is less toxic - more commonly used.)
- DNA intercalator - testicular & lymphomas - Pulmonary fibrosis mild myelosuppression.
competitive inhibirot of aldosterone in the cortical collecting tubule

4. Hydrochlorothiazide - clinical use?
Atropine would also block the receptors in the ciliary muscle - causing an impairment in accommodation (cycloplegia).
Tubocurarine - atracurium - mivacurium - pancuronium - vecuronium - rapacuronium
As PABA antimetabolites that inhibit Dihydropteroate Synthase - Bacteriostatic
HTN - CHF - calcium stone formation - nephrogenic DI.

5. A fellow passenger on a Carnival cruise ship looks pale and diaphoretic - What antimuscarinic agent would you give them?
Babiturate.
1. Phospholipase A2 is prevented from releasing arachidonic acid 2. Decreases protein synthesis thus lowering amount of Cyclooxygenase enzymes
- Phenytoin
scopolamine

6. List the specific antidote for this toxin: Antimuscarinic (anticholinergic)
- Physostigmine salicylate
Prevents the release of calcium from the sarcoplasmic reticulum of skeletal muscle.
vasodilator - increases cGMP to induce smooth muscle relaxation (arterioles>veins; afterload reduction)
Ibuprofen - Naproxen - and Indomethacin

7. Would blockade of muscarininc receptors in the bladder be useful in treating urinary retention?
No. Atropine is used to reduce urgency in mild cystitis. So it would aggravate the urinary retention.
1. Kidney transplantation 2. Autoimmune disorders (including glomerulonephritis and hemolytic anemia)
Ganciclovir is more toxic to host enzymes
Competitive inibitor of progestins at progesterone receptors.

8. ACE inhibitors - mechanism?
Hypersensitivity reactions
block voltage dependent L- type Ca2+ channels of cardiac and smooth muscle - decreasing contractility
reduce levels of Angiotensin II - thereby preventing the inactivation of bradykinin (a potent vasodilator); renin level is increased
- Tetracycline

9. Specifically - How does Foscarnet inhibit viral DNA pol?
Sulfonamide Loop Diuretic. Inhibits ion co - transport system of thick ascending loop. Abolishes hypertonicity of the medulla - thereby preventing concentration of the urine.
Binds to the Pyrophosphate Binding Site of the enzyme
Same as penicillin. Extended spectrum antibiotics
Triple sulfas or SMZ

10. List the specific antidote for this toxin: Copper
Prevents the release of calcium from the sarcoplasmic reticulum of skeletal muscle.
- Penicillamine
prevention of nodal arrhythmias (SVT)
Blocks translocation - binds to the 23S rRNA of the 50S subunit - Bacteriostatic

11. What populations are Floroquinolones contraindicated in? Why?
Pregnant women - Children; because animal studies show Damage to Cartilage
Epinephirine(Alpha1 -2 and Beta 1 -2)
Gram + cocci - Proteus mirabilis - E. coli - Klebsiella pneumoniae (PEcK)
hypertension - angina - arrhythmias

12. How can the toxic effects of TMP be ameliorated?
With supplemental Folic Acid
- Sulfonamides - INH - ASA - Ibuprofen - primaquine - nitrofurantoin /- pyrimethamine - chloramphenicol
Abortifacient.
thiazides - amiloride

13. Acetazolamide - toxicity?
- reduction - oxy - & hydrolysis - H2O sol. Polar product - P450
- Tetracycline
hyperchloremic metabolic acidosis - neuropathy - NH3 toxicity - sulfa allergy
They inhibit reuptake of NE at the nerve terminal (as does cocaine).

14. What is the effect of guanethidine on adrenergic NE release?
It inhibits release of NE.
None. No - because atropine would block the postganglionic muscarinic receptors involved in sweat gland stimulation.
1. Aluminum hydroxide: constipation and hypophosphatemia 2. Magnesium hydroxide: diarrhea 3. Calcium carbonate: Hypercalcemia - rebound acid increase - All may cause hypokalemia
Inhibit DNA Gyrase (topoisomerase II) - Bactericidal

15. What is the category - mechanism of action - and effect of Ipratroprium in Asthma treatment?
Edrophonium
Pentavalent Antimony
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)
Muscarinic antagonist; competatively blocks muscarinic receptors - preventing bronchoconstriction.

16. Mannitol - contraindications?
Protamine Sulfate is used for rapid reversal of heparinization (positively charged molecule that binds to negatively charged heparin).
depresses ectopic pacemakers - especially in digoxin toxicity
HSV - VZV - EBV - Mucocutaneous and Genital Herpes Lesions - Prophylaxis in Immunocompromised pts
anuria - CHF

17. What is the MOA of Polymyxins?
Choline acetyltransferase
With supplemental Folic Acid
Bind cell membrane - disrupt osmotic properties - Are Cationc - Basic and act as detergents
- Ethanol - dialysis - & fomepizole

18. Why is reserpine effective in treating HTN?
Inhalational general anesthetic.
- Alkalate DNA - Brain tumors - CNS toxicity
Reserpine inhibits dopamine transport into vesicles - attenuating its conversion to NE by dopamine beta - hydroxylase.
AluMINIMUM amount of feces.

19. Does Ampicillin or Amoxicillin have a greater oral bioavailability?
torsade de pointes
AmOxicillin has greater Oral bioavailability
Beta 2 agonist; used as a long - acting agent for prophylaxis. Adverse effects are tremor and arrhythmia.
- Triggers apoptosis - CLL - Hodgkin's in MOPP - Cushing - like syndrome

20. Which diuretics cause alkalosis?
Sulfonamide Loop Diuretic. Inhibits ion co - transport system of thick ascending loop. Abolishes hypertonicity of the medulla - thereby preventing concentration of the urine.
GI disturbances.
loop diuretics - thiazides
It affects beta receptors equally and is used in AV heart block (rare).

21. How is Ganciclovir used clinically?
decrease the slope of phase 4 - increase PR interval (the AV node is particularly sensitive)
Oxygen
CMV - esp in Immunocompromised patients
AmOxicillin has greater Oral bioavailability

22. What drugs target anticholinesterase
Chronic gout.
Neutropenia (ticlopidine); reserved for those who cannot tolerate aspirin.
Same as penicillin. Extended spectrum antibiotics
Neostigmine - pyridostigmine edrophonium - physostigmine echothiophate

23. Antimicrobial prophylaxis for PCP
TMP- SMZ (DOC) - aerosolized pentamidine
1. Mycobacterium tuberculosis 2. Delays resistance to Dapsone When used of Leprosy 3. Used in combination with other drugs
1. Taken daily 2. No protection against STDs 3. Raises triglycerides 4. Depression - weight gain - nausea - HTN 5. Hypercoagulable state
- Atropine & pralidoxime

24. A 57 yo heart failure pt develops cardiac decompensation - What drug will give you adequate perfusion of his kidneys as well as tx for his Hypotension
1. Significant: nephrotoxicity 2. Peripheral neuropathy 3. Hypertension 4. Pleural effusion 5. Hyperglycemia.
Dopamine
1. Better bioavailability 2. 2 to 4 times longer half life 3. Can be administered subcutaneously 4. Does not require laboratory monitoring
1. Antipyretic 2. Analgesic 3. Anti - inflammatory 4. Antiplatelet drug.

25. What are two processes Corticosteroids inhibit leading to decreased inflammation?
AZT
Praziquantel
1. RNA pol inhibitor 2. Revs up P450 3. Red/orange body fluids 4. Rapid resistance if used alone
1. Phospholipase A2 is prevented from releasing arachidonic acid 2. Decreases protein synthesis thus lowering amount of Cyclooxygenase enzymes

26. For Heparin What is the Onset of action
With supplemental Folic Acid
Rapid (seconds)
- Ethanol - dialysis - & fomepizole
Sotalol - Ibutilide - Bretylium - Amiodarone

27. Which drug(s) cause this reaction: Pseudomembranous colitis?
Slow - limited by half lives of clotting factors
- Clindamycin
1)Binds penicillin - binding proteins 2) Blocks transpeptidase cross - linking of cell wall 3) Activates autolytic enzymes
- reduction - oxy - & hydrolysis - H2O sol. Polar product - P450

28. List the mechanism - clinical use - & toxicity of Paclitaxel.
- MT polymerization stabilizer - Ovarian & breast CA - Myelosupperession & hypersensitivity.
- Tricyclic antidepressants
Aplastic anemia (dose independent) - Gray Baby Syndrome
Tricyclic antidepressant.

29. What are three unwanted effects of Mifepristone?
Impairs the synthesis of vitamin K- dependent clotting factors
Bleeding.
Spironolactone - Triamterene - Amiloride (the K+ STAys)
1. Heavy bleeding 2. GI effects (n/v - anorexia) 3. Abdominal pain

30. What additional side effects exist for Ampicillin?
Gemfibrozil - Clofibrate
Hemicholinium inhibits the transport of choline into the nerve - thus inhibiting formation of ACh.
Rash - Pseudomembranous colitis
edrophonium (extremely short acting anticholinesterase)

31. Ibutilide - toxicity?
Cardiac glycoside (inotropic agent).
torsade de pointes
Epinephrine
pulmonary edema - dehydration

32. Sotalol - toxicity?
Imipenem
Pentamidine
Doxycycline - because it is fecally eliminated
torsade de pointes - excessive Beta block

33. What is the clinical use for Nystatin?
Topical and Oral - for Oral Candidiasis (Thrush)
hyperchloremic metabolic acidosis - neuropathy - NH3 toxicity - sulfa allergy
Diarrhea
1. Peptic ulcer 2. Gastritis 3. Esophageal reflux 4. Zollinger - Ellison syndrome

34. Name the common Nucleoside Reverse Transcriptase Inhibitors
Blocks Influenza A and RubellA; causes problems with the cerebellA
Ceftriaxone
Zidovudine (AZT) - Didanosine (ddI) - Zalcitabine (ddC) - Stavudine (d4T) - Lamivudine (3TC)
new arrhythmias - hypotension

35. Explain pH dependent urinary drug elimination?
Keratin containing tissues - e.g. - nails
- Chloramphenicol - benzene - NSAIDS - PTU - phenytoin
- Weak Acids>Alkinalize urine(CO3) to remove more - Weak bases>acidify urine to remove more
Binding to the presynaptic alpha 2 release modulating receptors

36. For Warfarin What is the Site of action
Leukotrienes increasing bronchial tone.
Beta 2 agonist; desired effect is the relaxation of bronchial smooth muscle (Beta 2). Use during acute exacerbation.
Liver
Anaerobic infections (e.g. - B. fragilis - C. perfringens)

37. What type of patient should not take Misoprostol and why?
Protamine sulfate
Misoprostol is contraindicated in women of childbearing potential because it is an abortifacient.
collecting ducts
Inhibits Viral DNA polymerase

38. What are two conditions in Which COX-2 inhibitors might be used?
Bleeding.
Increases mean - systolic - and diastolic bp - while there is little change in pulse pressure.
Rheumatoid and osteoarthritis.
post MI and digitalis induced arrhythmias

39. What are the side effects of Rifampin?
Chronic gout.
Cyclooxygenases (COX I - COX II).
Misoprostol is contraindicated in women of childbearing potential because it is an abortifacient.
Minor hepatotoxicity - Drug interactions (activates P450)

40. Which drug(s) cause this reaction: Pulmonary fibrosis(3)?
1. Suppresses organ rejection after transplantation 2. Selected autoimmune disorders.
- Act on same receptor - Full has greater efficacy
- Bleomycin - amiodarone - busulfan
Penicillin.

41. Acetazolamide causes?

42. What is the receptor affinity and clinical use of isoproterenol?
- S- phase anti - metabolite folate analogue - Luk - Lymp - sarc - RA - & psoriasis / - Reversible myelosuppression
Antifungal.
1. Gastric ulceration 2. Bleeding 3. Hyperventilation 4. Reye's syndrome 5. Tinnitus (CN VIII)
It affects beta receptors equally and is used in AV heart block (rare).

43. What are three clinical uses of the NSAIDs?
Sotalol - Ibutilide - Bretylium - Amiodarone
Butyrophenone (neuroleptic).
1. Antipyretic 2. Analgesic 3. Anti - inflammatory
Blood

44. Explain potency in relation to full and partial agonists(2).
check PFTs - LFTs - and TFTs
No. Atropine is used to reduce urgency in mild cystitis. So it would aggravate the urinary retention.
- partial agonist can have increased - decreased - /A21or equal potency as full agonist. - Potency is an independent factor.
Beta -2 agonist.

45. Adverse effects of Nifedipine - verapamil?
dizziness - flushing - constipation (verapamil) - nausea
- Physostigmine salicylate
- Constant AMOUNT eliminated per unit time. - Etoh & ASA
Same as penicillin. Extended spectrum antibiotics

46. Mg+- clinical use?
GI upset
effective in torsade de pointes and digoxin toxicity
anuria - CHF
Methylxanthine.

47. What is the category of drug names ending in - oxin (e.g. Digoxin)
Succinylcholine
- Normalize K+ - Lidocaine - & Anti - dig Mab
1. Mycobacterium tuberculosis 2. Delays resistance to Dapsone When used of Leprosy 3. Used in combination with other drugs
Cardiac glycoside (inotropic agent).

48. Which drug(s) cause this reaction: Hot flashes?
hypertension - angina - arrhythmias
With supplemental Folic Acid
Milk or Antacids - because divalent cations inhibit Tetracycline absorption in the gut
- Tamoxifen

49. What is the category of drug names ending in - tidine (e.g. Cimetidine)
Decreased uptake or Increased transport out of cell
TMP- SMZ (DOC) - aerosolized pentamidine
H2 antagonist
No - it inhibits the release of Nor Epi

50. What are four conditions in Which H2 Blockers are used clinically?
1. Peptic ulcer 2. Gastritis 3. Esophageal reflux 4. Zollinger - Ellison syndrome
1. Bleeding 2. Teratogenicity 3. Drug - drug interactions
Mebendazole/Thiabendazole - Pyrantel Pamoate
Succinylcholine