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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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1. Ethacrynic Acid - mechanism?
Nifedipine - Verapamil - Diltiazem
- acetylation - glucuron. - & sulfation - Conjugation - Polar product
fetal renal toxicity - hyperkalemia - Cough - Angioedema - Proteinuria - Taste changes - hypOtension - Pregnancy problems - Rash - Increased renin - Lower Angiotensin II (CAPTOPRIL)
not a sulfonamide - but action is the same as furosemide

2. What is are two clinical uses of Cyclosporine?
1. Suppresses organ rejection after transplantation 2. Selected autoimmune disorders.
Penicillin.
Binds Ergosterol - forms Membrane Pores that Disrupt Homeostatis
- Disulfram & also sulfonylureas - metronidazole

3. What is the mechanism of action of Sildenafil (Viagra)?
- Niacin - Ca++ channel blockers - adenosine - vancomycin
Inhibits cGMP phosphodiesterase - casuing increased cGMP - smooth muscle relaxation in the corpus cavernosum - increased blood flow - and penile erection.
toxic
Oral

4. What is the clinical use for Sildenafil (Viagra)?
Erectile dysfunction.
Reserpine inhibits dopamine transport into vesicles - attenuating its conversion to NE by dopamine beta - hydroxylase.
- Shifts the curve down - reduces Vmax
Flecainide - Encainide - Propafenone

5. List the mechanism - clinical use - & toxicity of Paclitaxel.
Vd= (Amt. of drug in body/ Plasma drug conc.)
- MT polymerization stabilizer - Ovarian & breast CA - Myelosupperession & hypersensitivity.
Inhibits IMP Dehydrogenase (competitively) - and therefore blocks Guanine Nucleotide synthesis
- ACE inhibitors (Losartan>no cough)

6. Which drug(s) cause this reaction: Cutaneous flushing (4)?
- Corticosteroids - heparin
- Ethanol - dialysis - & fomepizole
Well tolerated in general but occasionally - Nephrotoxicity - Ototoxicity - Thrombophlebitis - diffuse flushing='Red Man Syndrome'
- Niacin - Ca++ channel blockers - adenosine - vancomycin

7. What are the clinical uses for 2nd Generation Cephalosporins?
impotence - exacerbation of asthma - CV effects - CNS effects - may mask hypoclycemia
Acute coronary syndrome; coronary stenting. Decreases the incidence or recurrence of thrombotic stroke.
Gram + cocci - Haemophilus influenza - Enterobacter aerogenes - Neisseria species - P. mirabilis - E. coli - K. pneumoniae - Serratia marcescens ( HEN PEcKS )
AZT

8. How does Ganciclovir's toxicity relate to that of Acyclovir?
In treatment of malignant hyperthermia - due to concomitant use of halothane and succinylcholine. Also in neuroleptic malignant syndrome - a toxicity of antipsychotic drugs.
- Glucagon
Ganciclovir is more toxic to host enzymes
Onchocerciasis ('river blindness'-- rIVER- mectin)

9. What is an additional side effect of Methicillin?
Interstitial nephritis
competitive inhibirot of aldosterone in the cortical collecting tubule
GI distress - Tooth discoloration and Inhibition of bone growth in children - Fanconi's syndrome - Photosensitivity
Liver

10. What microorganisms are clinical indications for Tetracycline therapy?

11. Name the steps in drug approval(4)?
Inhibits Viral DNA polymerase
- Phase I (clinical tests) - Phase II - Phase III - PhaseIV (surveillance)
Fever/Chills - Hypotension - Nephrotoxicity - Arrhythmias
SLUD (salivation - Lacrimation - urination - Defecation)as well as airway secretion - GI motility - acid secretions

12. Acetaminophen has What two clinical uses and lacks What one clinical use of the NSAIDs?
Inhibit Ergosterol synthesis
Acetaminophen has antipyretic and analgesic properties - but lacks anti - inflammatory properties.
effective in torsade de pointes and digoxin toxicity
Resistant Gram - infections

13. How is Amphotericin B administered for fungal meningitis?
Intrathecally
Meningitis (H. influenza - N. meningitidis - S. pneumoniae) - Conserative treatment due to toxicities
Benzathine penicillin G
Extended spectrum penicillin: certain Gram + bacteria and Gram - rods

14. For Heparin What is the Duration of action
carbonic anhydrase inhibitors - K+ sparing diuretics
PT
- Protamine
Acute (hours)

15. Are not penicillinase resistant
Leukopenia - Neutropenia - Thrombocytopenia - Renal toxicity
Carbenicillin - Piperacillin - and Ticarcillin
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.
Mebendazole/Thiabendazole - Pyrantel Pamoate

16. What is the category of drug names ending in - pril (e.g. Captopril)
Blocking muscarinic receptors in the circular fibers of the eye - results in unopposed action of radial muscles to dilate.
- Tamoxifen
1. Antipyretic 2. Analgesic 3. Anti - inflammatory 4. Antiplatelet drug.
ACE inhibitor.

17. Which of these three drugs will cause a reflex bradycardia in your pt (Norepi - Epi - or Isoporterenol)
Large anionic polymer - acidic
Directly of indirectly aid conversion of plasminogen to plasmin Which cleaves thrombin and fibrin clots. (It is claimed that tPA specifically converts fibrin - bound plasminogen to plasmin.)
Norepinephrine
1. Predisposes to viral infections and lymphoma 2. Nephrotoxic (preventable with mannitol diuresis)

18. How is Ribavirin used clinically?
- Ethosuxamide - sulfonamides - lamotrigine
NO HYPERURICEMIA - NO SULFA AllERGY; same as furosemide otherwise
for RSV
Benzodiazepine.

19. What are two toxicities of the Glitazones?
- Nitrate - hydroxocobalamin thiosulfate
Carbenicillin - Piperacillin - and Ticarcillin
Chronic gout.
1. Weight gain 2. Hepatotoxicity (troglitazone)

20. For Warfarin What is the Ability to inhibit coagulation in vitro
Norepinephrine (Alpha1 -2 and beta 1)
VACUUM your Bed Room'
No
Increased systolic and pulse pressure - decreased diastolic pressure - and little change in mean pressure.

21. What physiological effects was the Anes using Atropine to tx
Binding to the presynaptic alpha 2 release modulating receptors
Liver
SLUD (salivation - Lacrimation - urination - Defecation)as well as airway secretion - GI motility - acid secretions
Beta adrenergic receptors and Ca2+ channels (stimulatory)

22. What is the MOA for the Aminoglycosides?
Chronic gout.
NE increases bp - Which stimulates baroreceptors in the carotid sinus and the aorta. The CNS signals through vagal stimulation to decrease heart rate.
Inhibits formation of Initiation Complex - causes misreading of mRNA - Bactericidal
Hemolysis (if G6PD deficient) - Neurotoxicity - Hepatotoxicity - SLE- like syndrome

23. How would you treat African Trypanosomiasis (sleeping sickness)?
Megaloblastic anemia - Leukopenia - Granulocytopenia
hyperkalemia - endocrine effects (gynecomastia - anti - androgen)
Lovastatin - Pravastatin - Simvastatin - Atorvastatin
Suramin

24. Why are albuterol and terbutaline effective in tx of acute asthmatic attacks?
vascular sm. Mus.: Nifedipine>Diltiazem>Verapamil
These B-2 agonists cause respiratory smooth muscle to relax.
Inhibits reabsorption of uric acid.
Gentamicin - Neomycin - Amikacin - Tobramycin - Streptomycin

25. Common side effects associated with Clindamycin include?
1. Hydrocortisone 2. Predisone 3. Triamcinolone 4. Dexamethasone 5. Beclomethasone
Malaria (P. falciparum)
Leukotrienes increasing bronchial tone.
Pseudomembranous colitis (C. difficile) - fever - diarrhea

26. For Warfarin What is the Treatment for overdose
IV vitamin K and fresh frozen plasma
Phosphorylation by a Viral Kinase
1) Hypersensitivity reactions 2) Increased nephrotoxicity of Aminoglycosides 3) Disulfiram - like reaction with ethanol (those with a methylthiotetrazole group - e.g. - cefamandole)
INH: Injures Neurons and Hepatocytes

27. What drugs target anticholinesterase
Nephrotoxicity (esp. with Cephalosporins) - Ototoxicity (esp. with Loop Diuretics)
Neostigmine - pyridostigmine edrophonium - physostigmine echothiophate
proximal convoluted tubule
Botulinum

28. What is the major side effect for Ampicillin and Amoxicillin?
For serious - Gram + multidrug - resistant organisms
Hypersensitivity reactions
Penicillin - V
Diarrhea - Urination - Miosis - Bronchospasm - Bradycardia - Excitation of skeletal muscle and CNS - Lacrimation - Sweating - and Salivation = DUMBBELS; also abdominal cramping

29. What is the MOA for Trimethoprim (TMP)?
Butyrophenone (neuroleptic).
Inhibits bacterial Dihydrofolate Reductase - Bacteriostatic
1. Significant: nephrotoxicity 2. Peripheral neuropathy 3. Hypertension 4. Pleural effusion 5. Hyperglycemia.
Antimetabolite derivative of 6- mercaptopurine that interferes with the metablolism and synthesis of nucleic acid.

30. Which drug(s) cause this reaction: Tubulointerstitial Nephritis (5)?
- Sulfonamides - furosemide - methicillin - rifampin - NSAIDS (ex. ASA)
NO
G6PD deficient individuals
Increased systolic and pulse pressure - decreased diastolic pressure - and little change in mean pressure.

31. What is the category of drug names ending in - cycline (e.g. Tetracycline)
- Ethanol - dialysis - & fomepizole
Antibiotic - protein synthesis inhibitor.
Inhibits DNA dependent RNA polymerase
- Steroids - Tamoxifen

32. List the mechanism - clinical use - & toxicity of Cisplatin.
- Alkalating agent - testicular - bladder - ovary -& lung - Nephrotoxicity & CN VIII damage.
- Protamine
- Chloramphenicol
GI upset - Superinfections - Skin rashes - Headache - Dizziness

33. What is the clinical use of Mifepristone (RU486)?
- Shifts the curve to the right - increases Km
- S- phase anti - metabolite folate analogue - Luk - Lymp - sarc - RA - & psoriasis / - Reversible myelosuppression
No
Abortifacient.

34. What is a prerequisite for Acyclovir activation?
Benzodiazepine.
ACIDazolamide' causes acidosis
It must be Phosphorylated by Viral Thymidine Kinase
Pyridoxine (B6) administration

35. MOA: Block cell wall synthesis by inhib. Peptidoglycan cross - linking (7)
collecting ducts
Gram + cocci - Gram - rods - and Anerobes
Penicillin - Ampicillin - Ticarcillin - Pipercillin - Imipenem - Aztreonam - Cephalosporins
-100% oxygen - hyperbaric

36. Resistance mechanisms for Aminoglycosides
Antileukotriene; blocks synthesis by lipoxygenase.
Misoprostol is contraindicated in women of childbearing potential because it is an abortifacient.
proximal convoluted tubule
Modification via Acetylation - Adenylation - or Phosphorylation

37. Which drug(s) cause this reaction: Tendonitis and rupture?
- Fluoroquinolones
Modification via Acetylation
Ca2+ (Loops Lose calcium)
fetal renal toxicity - hyperkalemia - Cough - Angioedema - Proteinuria - Taste changes - hypOtension - Pregnancy problems - Rash - Increased renin - Lower Angiotensin II (CAPTOPRIL)

38. What class of drug is echothiophate? What is its indication?
- Tetracycline - amiodarone - sulfonamides
Indirect agonist - uptake inhibitor
anticholinesterase glaucoma
Parkinson patients benefit from antimuscarinic agents through its inhibitory action within the indirect pathway.

39. What is the mechanism of action of Misoprostol?
Keratin containing tissues - e.g. - nails
carbonic anhydrase inhibitors - K+ sparing diuretics
Misoprostol is a PGE1 analog that increases the production and secretion of the gastic mucous barrier.
Nephrotoxicity (esp. with Cephalosporins) - Ototoxicity (esp. with Loop Diuretics)

40. Toxic side effects of the Azoles?
Hormone synthesis inhibition (Gynecomastia) - Liver dysfunction (Inhibits CYP450) - Fever - Chills
Nucleosides
Competitive inibitor of progestins at progesterone receptors.
Can affect absorption - bioavailability - or urinary excretion of other drugs by altering gastric and urinary pH or by delaying gastric emptying.

41. Adverse effect of Nitroprusside?
As PABA antimetabolites that inhibit Dihydropteroate Synthase - Bacteriostatic
Liver
cyanide toxicity (releases CN)
vascular sm. Mus.: Nifedipine>Diltiazem>Verapamil

42. Furosemide - class and mechanism?
Altered bacterial Dihydropteroate Synthetase - Decreased uptake - or Increased PABA synthesis
torsade de pointes
Sulfonamide Loop Diuretic. Inhibits ion co - transport system of thick ascending loop. Abolishes hypertonicity of the medulla - thereby preventing concentration of the urine.
Theoretically it could be used to block the cephalic phase of acid secretion (vagal stimulation).

43. Cocaine shares is mechanism of action with What antidepressant
Oxygen
TCA
Treatment of hypertension - especially with renal disease (lowers bp centrally - so flow is maintained to kidney).
Doxycycline - because it is fecally eliminated

44. For Heparin What is the Lab value to monitor
WEPT: Warfarin affects the Extrinsic pathway and prolongs the PT.
local anesthetic. CNS stimulation or depression. CV depression.
aPTT (intrinsic pathway)
Pralidoxime regenerates active cholinesterase.

45. How does a noncompetitive antagonist effect an agonist?
Protamine sulfate
- Shifts the curve down - reduces Vmax
- Ammonium Chloride
Used in combination therapy with SMZ to sequentially block folate synthesis

46. What is the effect of epinephrine infusion on bp and pulse pressure?
torsade de pointes
Increased systolic and pulse pressure - decreased diastolic pressure - and little change in mean pressure.
sedation - positive Coombs' test
Potent immunosuppressive used in organ transplant recipients.

47. Acetazolamide causes?

48. Digoxin v. Digitoxin: excretion?
- Cimetidine - ketoconazole - spironolactone - digitalis - EtOH - estrogens
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.
The PT.
Digoxin=urinary Digitoxin=biliary

49. What drug is used to diagnose myasthenia gravis?
Activates cholinergic receptors on bladder and bowel smooth muscle - alleviating post - op and neurogenic ileus and urinary retention.
Inhibit Ergosterol synthesis
Initially vasoconstriction would increase bp - but then it acts on central alpha -2 receptors to decrease adrenergic outflow resulting in decreased bp.
edrophonium (extremely short acting anticholinesterase)

50. Which diuretics cause acidosis?
orthostatic and exercise hypotension - sexual dysfunction - diarrhea
carbonic anhydrase inhibitors - K+ sparing diuretics
decrease the slope of phase 4 - increase PR interval (the AV node is particularly sensitive)
Hypokalemic metabolic alkalosis - hyponatremia - hyperGlycemia - hyperLipidemia - hyperUricemia - hyperCalcemia - sulfa allergy.