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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 of drug names ending in - olol (e.g. Propranolol)
Beta antagonist.
torsade de pointes - excessive Beta block
aPTT (intrinsic pathway)
Ca2+ (Loops Lose calcium)

2. Why would dopamine be useful in treating shock?
Receptors = D1=D2>beta>alpha - thus increasing heart rate (beta) and blood pressure (alpha vasoconstriction) while maintaining kidney perfusion (dopamine receptors)
Bind cell membrane - disrupt osmotic properties - Are Cationc - Basic and act as detergents
- Fluoroquinolones
atropine - homatropine - tropicamide

3. Triamterene and amiloride - mechanism?
dry mouth - sedation - severe rebound hypertension
- Barbiturates - phenytoin - carbamazipine - rifampin - griseofulvin - quinidine
block Na+ channels in the cortical collecting tubule
GI discomfort - Acute cholestatic hepatitis - Eosinophilia - Skin rashes

4. Hydrochlorothiazide - clinical use?
HTN - CHF - calcium stone formation - nephrogenic DI.
- Constant AMOUNT eliminated per unit time. - Etoh & ASA
fetal renal toxicity - hyperkalemia
increased AP duration - increased ERP increased QT interval. Atrial and ventricular.

5. For Heparin What is the Onset of action
Rare.
dizziness - flushing - constipation (verapamil) - nausea
pulmonary edema - dehydration
Rapid (seconds)

6. What are are the Sulfonylureas (general description) and What is their use?
Decreased uptake or Increased transport out of cell
Methylxanthine.
Sulfonylureas are oral hypoglycemic agents - they are used to stimulate release of endogenous insulin in NIDDM (type -2).
- acetylation - glucuron. - & sulfation - Conjugation - Polar product

7. Resistance mechanisms for Chloramphenicol
Modification via Acetylation
reversible SLE- like syndrome
1. Meningococcal carrier state 2. Chemoprophylaxis in contacts of children with H. influenzae type B
Indirect agonist - uptake inhibitor

8. What is the MOA for Metronidazole?
Hexamethonium is a nicotinic antagonist - and thus is a ganglionic blocker.
1. Kidney transplantation 2. Autoimmune disorders (including glomerulonephritis and hemolytic anemia)
CMV - esp in Immunocompromised patients
Forms toxic metabolites in the bacterial cell - Bactericidal

9. What is the effect of TCA's on the adrenergic nerve?
1. Predisposes to viral infections and lymphoma 2. Nephrotoxic (preventable with mannitol diuresis)
Acts as a wide spectrum carbapenem
Erythromycin - Azithromycin - Clarithromycin
They inhibit reuptake of NE at the nerve terminal (as does cocaine).

10. Which drug(s) cause this reaction: Thrombotic complications?
- Oral Contraceptives
Interstitial nephritis
- Glucagon
Parkinson patients benefit from antimuscarinic agents through its inhibitory action within the indirect pathway.

11. What neurotransmitter does Amantadine affect? How does it influence this NT?
Dopamine; causes its release from intact nerve terminals
Lidocaine - Mexiletine - Tocainide
Protamine Sulfate is used for rapid reversal of heparinization (positively charged molecule that binds to negatively charged heparin).
decrease AP duration - affects ischemic or depolarized Purkinje and ventricular system

12. Decrease Digoxin dose in renal failure?
YES
NE increases bp - Which stimulates baroreceptors in the carotid sinus and the aorta. The CNS signals through vagal stimulation to decrease heart rate.
Chronic gout.
Sucralfate cannot work in the presence of antacids or H2 blockers because it requires an acidic environment to polymerize.

13. Oral Penicillin
Close K+ channels in Beta - cell membrane leading to cell depolarization causing insulin release triggered by increase in Calcium ion influx.
1. Heavy bleeding 2. GI effects (n/v - anorexia) 3. Abdominal pain
Penicillin - V
- Penicillamine

14. Mg+- clinical use?
effective in torsade de pointes and digoxin toxicity
TMP- SMZ
reduce levels of Angiotensin II - thereby preventing the inactivation of bradykinin (a potent vasodilator); renin level is increased
GI upset

15. Amiodarone - toxicity?
pulmonary fibrosis - corneal deposits - hepatotoxicity - skin deposits resulting in photodermatitis - neurologic effects - consitpation - CV (bradycardia - heart block - CHF) - and hypo - or hyperthyroidism.
Pentamidine
Methylxanthine.
Dermatophytes (tinea - ringworm)

16. What are two Alpha - glucosidase inhibitors?
Antimetabolite derivative of 6- mercaptopurine that interferes with the metablolism and synthesis of nucleic acid.
Protease Inhibitors and Reverse Transcriptase Inhibitors
1. Acarbose 2. Miglitol
Intrathecally

17. What is the mechanism of action and clinical use of the antiandrogens Ketoconazole and Spironolactone?
Succinylcholine
BM suppression (neutropenia - anemia) - Peripheral neuropathy
Blocks Norepi - but not Dopamine
Inhibit steroid synthesis - used in the treatment of polycystic ovarian syndrome to prevent hirsutism.

18. Antiarrhythmic class II- mechanism?
Vibrio cholerae Acne Chlamydia Ureaplasma Urealyticum Mycoplasma pneumoniae Borrelia burgdorferi (Lyme's) Rickettsia Tularemia
Altered bacterial Dihydropteroate Synthetase - Decreased uptake - or Increased PABA synthesis
Digitoxin>95% Digoxin 75%
blocking the beta adrenergic receptor leads to decreased cAMP - and decreased Ca2+ flux

19. Are not penicillinase resistant
Carbenicillin - Piperacillin - and Ticarcillin
- Alkalating agent - NHL - Breast - ovary - & lung. - Myelosuppression - & hemorrhagic cystitis.
alpha -1 > alpha -2; used as a pupil dilator - vasoconstrictor - and for nasal decongestion
Neomycin

20. Secretion of What drug is inhibited by Probenacid used to treat chronic gout?
- Ammonium Chloride
Short.
Mebendazole/Thiabendazole - Pyrantel Pamoate
Penicillin.

21. How does resistance to Vancomycin occur?
Penicillin - V
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.
With an amino acid change of D- ala D- ala to D- ala D- lac
1. Hydrocortisone 2. Predisone 3. Triamcinolone 4. Dexamethasone 5. Beclomethasone

22. What Sulfonamides are used for simple UTIs?
Ciprofloxacin - Norfloxacin - Ofloxacin - Grepafloxacin - Enoxacin - Nalidixic acid
As an anticholinesterase it increases endogenous ACh and thus increases strength.
The COX-2 inhibitors should not have the corrosive effects of other NSAIDs on the gastrointestinal lining.
Triple sulfas or SMZ

23. List the specific antidote for this toxin: Warfarin
Misoprostol is a PGE1 analog that increases the production and secretion of the gastic mucous barrier.
fetal renal damage - hyperkalemia - Cough - Angioedema - Proteinuria - Taste changes - hypOtension - Pregnancy problems - Rash - Increased renin - Lower Angiotensin II (CAPTOPRIL)
- NaHCO3
- Vitamin K & fresh frozen plasma

24. K+ sparing diuretics - clinical use?
- Cimetidine - ketoconazole - grapefruit juice - erythromycin - INH - sulfonamides
Sucralfate cannot work in the presence of antacids or H2 blockers because it requires an acidic environment to polymerize.
Epinephrine to treat anaphylaxis. Also useful if you have open angle glaucoma - asthma - or hypotension.
hyperaldosteronism - K+ depletion - CHF

25. MOA: Block peptidoglycan synthesis
compensatory tachycardia - fluid retention - lupus - like syndrome
- Topo II inhibitor(GII specific) - Oat cell of Lung & prostate - & testicular - Myelosuppression & GI irritation.
Bacitracin - Vancomycin
hyperkalemia - endocrine effects (gynecomastia - anti - androgen)

26. What is Clindamycin used for clinically?
G6PD deficient individuals
Enterobacter
Anaerobic infections (e.g. - B. fragilis - C. perfringens)
Protease Inhibitors and Reverse Transcriptase Inhibitors

27. What are the clinical uses for 2nd Generation Cephalosporins?
Ibuprofen - Naproxen - and Indomethacin
Inhibits organification and coupling of thyroid hormone synthesis. Also decreases peripheral conversion of T4 to T3.
loop diuretics - thiazides
Gram + cocci - Haemophilus influenza - Enterobacter aerogenes - Neisseria species - P. mirabilis - E. coli - K. pneumoniae - Serratia marcescens ( HEN PEcKS )

28. What is the clinical use for Sucralfate?
Binding to the presynaptic alpha 2 release modulating receptors
Digoxin=urinary Digitoxin=biliary
Peptic ulcer disease.
Norepinephrine

29. Furosemide - class and mechanism?
Ataxia - Dizziness - Slurred speech
Sulfonamide Loop Diuretic. Inhibits ion co - transport system of thick ascending loop. Abolishes hypertonicity of the medulla - thereby preventing concentration of the urine.
Chronic gout.
carbonic anhydrase inhibitors - K+ sparing diuretics

30. What is the MOA for Methicillin - Nafcillin - and Dicloxacillin?
- Deferoxamine
1. Aluminum hydroxide: constipation and hypophosphatemia 2. Magnesium hydroxide: diarrhea 3. Calcium carbonate: Hypercalcemia - rebound acid increase - All may cause hypokalemia
Same as penicillin. Act as narrow spectrum antibiotics
Acute gout.

31. What are the clinical uses for 1st Generation Cephalosporins?
1. Antipyretic 2. Analgesic 3. Anti - inflammatory
1. Antiandrogen 2. Nausea 3. Vomiting
Gram + cocci - Proteus mirabilis - E. coli - Klebsiella pneumoniae (PEcK)
1. Predisposes to viral infections and lymphoma 2. Nephrotoxic (preventable with mannitol diuresis)

32. Name some common Tetracyclines (4)
- Estrogen receptor antagonist - Breast CA - increased endometrial CA risk
Early myocardial infarction.
Tetracycline - Doxycycline - Demeclocycline - Minocycline
sedation - depression - nasal stuffiness - diarrhea

33. Which RT inhibitor causes Megaloblastic Anemia?
Teratogenic - Carcinogenic - Confusion - Headaches
Inhibits cell wall mucopeptide formation - Bactericidal
AZT
Chagas' disease - American Trypanosomiasis (Trypanosoma cruzi)

34. What are the side effects of Rifampin?
Ceftriaxone
Minor hepatotoxicity - Drug interactions (activates P450)
1. Tolbutamide 2. Chlorpropamide 3. Glyburide 4. Glipizide
Triple sulfas or SMZ

35. What is the mechanism of Azathioprine?
Rare.
Bactericidal for: Gram + rod and cocci - Gram - cocci - and Spirochetes
Antimetabolite derivative of 6- mercaptopurine that interferes with the metablolism and synthesis of nucleic acid.
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.

36. Which RT inhibitors cause Lactic Acidosis?
GI discomfort
Nucleosides
Inhibits cell wall mucopeptide formation - Bactericidal
1. Hypoglycemia (more common with 2nd - generation drugs: glyburide - glipizide) 2. Disulfiram - like effects (not seen with 2nd - generation drugs).

37. What is the MOA of Amantadine?
Headache - flushing - dyspepsia - blue - green color vision.
Blocks viral penetration/uncoating; may act to buffer the pH of the endosome
Hemicholinium inhibits the transport of choline into the nerve - thus inhibiting formation of ACh.
check PFTs - LFTs - and TFTs

38. What is the category of drug names ending in - ipramine (e.g. Imipramine)
- Chlorpromazine - thioridazine - haloperidol
Tricyclic antidepressant.
Indomethacin is used to close a patent ductus arteriosus.
Rifampin

39. List the mechanism - clinical use - & toxicity of 6 MP.
- inhibits HGPRT (pur. Syn.) - Luk - Lymph
Primaquine
sedation - positive Coombs' test
anuria - CHF

40. Resistance mechanisms for Vancomycin
Terminal D- ala of cell wall replaced with D- lac; Decreased affinity
Penicillin - Cephalosporins - Vancomycin - Aminoglycosides - Fluoroquinolones - Metronidazole
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
NO HYPERURICEMIA - NO SULFA AllERGY; same as furosemide otherwise

41. Which drug(s) cause this reaction: Stevens - Johnson syn. (3)?
Nonspecific beta - agonist; desired effect is the relaxation of bronchial smooth muscle (Beta 2). Adverse effect is tachycardia (Beta 1).
Tricyclic antidepressant.
- Ethosuxamide - sulfonamides - lamotrigine
When pts have Low CD4+ (< 500 cells/cubic mm) or a High Viral Load

42. What is the category and mechanism of action of Zileuton in Asthma treatment?
Penicillin.
- Sulfonamides - furosemide - methicillin - rifampin - NSAIDS (ex. ASA)
Penicillin - G
Antileukotriene; blocks synthesis by lipoxygenase.

43. What are Aminoglycosides used for clinically?
Hydralazine and Minoxidil
Severe Gram - rod infections.
Penicillin - V
Staphlococcus aureus

44. What are toxic side effects for Metronidazole?
Disulfiram - like reaction with EtOH - Headache
Rifampin
Zidovudine (AZT) - Didanosine (ddI) - Zalcitabine (ddC) - Stavudine (d4T) - Lamivudine (3TC)
cinchonism: HA - tinnitus - thrombocytopenia - torsade de pointes due to increased QT interval

45. For Warfarin What is the Site of action
Liver
- DNA intercalator - Hodgkin's - myeloma - sarcoma - and solid tumors - Cardiotoxicity & alopecia
No
- Fluoroquinolones

46. What are Polymyxins used for?
Antifungal.
all of them
Resistant Gram - infections
Acute (hours)

47. Name five Antiarrhythmic drugs in class II?
torsade de pointes
propanolol - esmolol - metoprolol - atenolol - timolol
Carbachol - pilocarpine - physostigmine - echothiophate
Butyrophenone (neuroleptic).

48. Which drug(s) cause this reaction: Photosensitivity(3)?
scopolamine
- Tetracycline - amiodarone - sulfonamides
Close K+ channels in Beta - cell membrane leading to cell depolarization causing insulin release triggered by increase in Calcium ion influx.
1. Streptokinase 2. Urokinase 3. tPA (alteplase) - APSAC (anistreplase)

49. What are the clinical uses for 3rd Generation Cephalosporins?
Constant FRACTION eliminated per unit time.(exponential)
loop diuretics - spironolactone
Used in combination therapy with SMZ to sequentially block folate synthesis
1) Serious Gram - infections resistant to other Beta lactams 2) Meningitis (most penetrate the BBB)

50. List the specific antidote for this toxin: Beta Blockers
Carbenicillin - Piperacillin - and Ticarcillin
Fever/Chills - Hypotension - Nephrotoxicity - Arrhythmias
- Glucagon
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