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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. Which drug(s) cause this reaction: Cardiac toxicity?
Inhibits CMV DNA polymerase
Ataxia - Dizziness - Slurred speech
- Daunorubicin & Doxorubicin
- Sulfonamides - furosemide - methicillin - rifampin - NSAIDS (ex. ASA)

2. Adenosine - clinical use?
DOC in diagnosing and abolishing AV nodal arrhythmias
depresses ectopic pacemakers - especially in digoxin toxicity
- Niacin - Ca++ channel blockers - adenosine - vancomycin
The COX-2 inhibitors should not have the corrosive effects of other NSAIDs on the gastrointestinal lining.

3. What is the mecanism of action of the COX-2 inhibitors (celecoxib - rofecoxib)?
Acetylcholine esterase
1. Infertility (pulsatile) 2. Prostate cancer (continuous: use with flutamide) 3. Uterine fibroids
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.
Vd= (Amt. of drug in body/ Plasma drug conc.)

4. Name two classes of drugs for HIV therapy
Sulfonamide Loop Diuretic. Inhibits ion co - transport system of thick ascending loop. Abolishes hypertonicity of the medulla - thereby preventing concentration of the urine.
Butyrophenone (neuroleptic).
fetal renal damage - hyperkalemia - Cough - Angioedema - Proteinuria - Taste changes - hypOtension - Pregnancy problems - Rash - Increased renin - Lower Angiotensin II (CAPTOPRIL)
Protease Inhibitors and Reverse Transcriptase Inhibitors

5. What are four unwanted effects of Clomiphene use?
- Topo II inhibitor(GII specific) - Oat cell of Lung & prostate - & testicular - Myelosuppression & GI irritation.
Rare.
Post - op and neurogenic ileus and urinary retention - myasthenia gravis - and reversal of neuromuscular junction blockade (post - op) through anticholinesterase activity.
1. Hot flashes 2. Ovarian enlargement 3. Multiple simultaneous pregnancies 4. Visual disturbances

6. What is a possible toxicity of Alpha - glucosidase inhibitors used in type -2 diabetes?
- Infections - Trauma - Seizures - CO - Overdose - Metabolic - Alcohol (IT'S COMA)
anticholinesterase glaucoma
GI disturbances.
Verapamil - Diltiazem - Bepridil

7. Can Heparin be used during pregnancy?
effective in torsade de pointes and digoxin toxicity
toxic
Cardiac glycoside (inotropic agent).
Yes - it does not cross the placenta.

8. Which drug(s) cause this reaction: Extrapyramidal side effects (3)?
- DNA intercalator - Hodgkin's - myeloma - sarcoma - and solid tumors - Cardiotoxicity & alopecia
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.
- Chlorpromazine - thioridazine - haloperidol
Alpha -1 antagonist

9. Antiarrhythmic class IV- primary site of action?
The only local anesthetic with vasoconstrictive properties.
Blocks Peptide Bond formation at the 50S subunit - Bacteriostatic
first dose orthostatic hypotension - dizziness - headache
AV nodal cells

10. ACE inhibitors - mechanism?
1. RNA pol inhibitor 2. Revs up P450 3. Red/orange body fluids 4. Rapid resistance if used alone
reduce levels of Angiotensin II - thereby preventing the inactivation of bradykinin (a potent vasodilator); renin level is increased
cholestyramine - colestipol
pulmonary fibrosis - corneal deposits - hepatotoxicity - skin deposits resulting in photodermatitis - neurologic effects - consitpation - CV (bradycardia - heart block - CHF) - and hypo - or hyperthyroidism.

11. Bretyllium - toxicity?
Increased systolic and pulse pressure - decreased diastolic pressure - and little change in mean pressure.
INH: Injures Neurons and Hepatocytes
DOC in diagnosing and abolishing AV nodal arrhythmias
new arrhythmias - hypotension

12. What is the clinical use for Sucralfate?
Amphotericin B - Nystatin - Fluconazole/azoles
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.
Peptic ulcer disease.
- Chloramphenicol

13. Which drug(s) cause this reaction: Disulfram - like reaction (4) ?
- Weak Acids>Alkinalize urine(CO3) to remove more - Weak bases>acidify urine to remove more
physostigmine
Hypokalemic metabolic alkalosis - hyponatremia - hyperGlycemia - hyperLipidemia - hyperUricemia - hyperCalcemia - sulfa allergy.
- Metronidazole - certain cephalosporins - procarbazine - sulfonylureas

14. If a patient is given hexamethonium - What would happen to his/her heart rate?
Vibrio cholerae Acne Chlamydia Ureaplasma Urealyticum Mycoplasma pneumoniae Borrelia burgdorferi (Lyme's) Rickettsia Tularemia
cardiac depression - peripheral edema - flushing - dizziness - constipation
Hypersensitivity reactions
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.

15. What is the MOA for Acyclovir?
Blocking muscarinic receptors in the circular fibers of the eye - results in unopposed action of radial muscles to dilate.
Flutamide is a nonsteroidal competitive inhibitor of androgens at the testosterone receptor - used in prostate carcinoma.
- Methotrexate - 5 FU - 6 mercaptopurine
Inhibit viral DNA polymerase

16. Adverse effects of Captopril?
fetal renal toxicity - hyperkalemia - Cough - Angioedema - Proteinuria - Taste changes - hypOtension - Pregnancy problems - Rash - Increased renin - Lower Angiotensin II (CAPTOPRIL)
Chloramphenicol - Erythromycin/macrolides - Lincomycin - Clindamycin - Streptogramins (quinupristin - dalfopristin)
NE increases bp - Which stimulates baroreceptors in the carotid sinus and the aorta. The CNS signals through vagal stimulation to decrease heart rate.
cardiac depression - peripheral edema - flushing - dizziness - constipation

17. List the specific antidote for this toxin: TPA & Streptokinase
Decrease the production of leukotrienes and protaglandins by inhibiting phospholipase A2 and expression of COX-2.
AluMINIMUM amount of feces.
- Aminocaproic acid
Gentamicin - Neomycin - Amikacin - Tobramycin - Streptomycin

18. What neurotransmitter does Amantadine affect? How does it influence this NT?
Dopamine; causes its release from intact nerve terminals
Reversibly inhibit cyclooxygenase (COX I and COX II). Block prostaglandin synthesis.
Digoxin=urinary Digitoxin=biliary
Giardiasis - Amoebic dysentery (E. histolytica) - Bacterial vaginitis (Gardnerella vaginalis) - Trichomonas

19. What is the definition of zero - order kinetics? Example?
- Shifts the curve down - reduces Vmax
- Constant AMOUNT eliminated per unit time. - Etoh & ASA
Ataxia - Dizziness - Slurred speech
increased AP duration - increased ERP increased QT interval. Atrial and ventricular.

20. How are Interferons (INF) used clinically?

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21. Reserpine will block the syntheis of this drug and but not its precursor.
- Penicillin
Beta lactams - inhibit cell wall synthesis - Bactericidal
Blocks Norepi - but not Dopamine
1. Kidney transplantation 2. Autoimmune disorders (including glomerulonephritis and hemolytic anemia)

22. What is the category of drug names ending in - zosin (e.g. Prazosin)
Beta 2 agonist; desired effect is the relaxation of bronchial smooth muscle (Beta 2). Use during acute exacerbation.
Cestode/tapeworm (e.g. - D. latum - Taenia species Except Cysticercosis
Alpha -1 antagonist
Ipratropium

23. Amprotericin B ___________ the BBB
Albuterol - tertbutaline
Does not cross
all except the K+ sparing diuretics Spironolactone - Triamterene - Amiloride
Rare.

24. What is the MOA of Foscarnet?
Meningitis (H. influenza - N. meningitidis - S. pneumoniae) - Conserative treatment due to toxicities
Mechanism unknown; possibly inhibits gluconeogenesis and increases glycolysis; effect is to decrease serum glucose levels
Na/K ATPase
Inhibits Viral DNA polymerase

25. What are three toxicities of Leuprolied?
Acetylcholinesterase; ACh is broken down into choline and acetate.
1. Antiandrogen 2. Nausea 3. Vomiting
cardiac depression - peripheral edema - flushing - dizziness - constipation
decrease conduction velocity - increase ERP - increase PR interval

26. Adverse effects of Methyldopa?

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27. What is Metronidazole combined with for 'triple therapy'? Against What organism?
Bismuth and Amoxicillin or Tetracycline; against Helobacter pylori
GI discomfort
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.
Norepinephrine

28. What is a common side effect of Colchicine used to treat acute gout - especially When given orally?
GI side effects. (Indomethacin is less toxic - more commonly used.)
- Quinidine - quinine
hyperkalemia - endocrine effects (gynecomastia - anti - androgen)
The only local anesthetic with vasoconstrictive properties.

29. MOA: Block protein synthesis at 30s subunit
Immediate anticoagulation for PE - stroke - angina - MI - DVT.
Aminoglycosides - Tetracyclines
Acetylcholine esterase
Leukotrienes increasing bronchial tone.

30. What is the mechanism of action of Sildenafil (Viagra)?
Lipoxygenase
Rheumatoid and osteoarthritis.
Inhibits cGMP phosphodiesterase - casuing increased cGMP - smooth muscle relaxation in the corpus cavernosum - increased blood flow - and penile erection.
1. Renal damage 2. Aplastic anemia 3. GI distress

31. What is the mechanism of action of Omeprazole - Lansoprazole?
toxic
- Flumazenil
is resistant
Irreversibly inhibits H+/K+ ATPase in stomach parietal cells.

32. Acetazolamide - site of action?
Polymyxins
proximal convoluted tubule
1.Gram - rods of the Urinary and GI tracts (including Pseudomonas) 2.Neisseria 3. Some Gram + organisms
Beta - lactamase cleavage of Beta - lactam ring

33. What enzyme is responsible for the breakdown of ACh in the synaptic cleft?
Acetylcholinesterase; ACh is broken down into choline and acetate.
Mycobacterium tuberculosis - the only agent used as solo prophylaxis against TB
With an amino acid change of D- ala D- ala to D- ala D- lac
Acute coronary syndrome; coronary stenting. Decreases the incidence or recurrence of thrombotic stroke.

34. What is the mechanism of Leuprolide?
Oral treatment of superficial infections
- Niacin - Ca++ channel blockers - adenosine - vancomycin
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
Inhibits platelet aggregation by irreversibly inhibiting the ADP pathway involved in the binding of fibrinogen.

35. What is the MOA for Metronidazole?
Forms toxic metabolites in the bacterial cell - Bactericidal
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.)
Inhibits NaCl reabsorption in the early distal tubule. Decreases Ca2+ excretion.
Atropine would also block the receptors in the ciliary muscle - causing an impairment in accommodation (cycloplegia).

36. What are three clinical uses of the Leuprolide?
Pseudomonas species and Gram - rods
For serious - Gram + multidrug - resistant organisms
Treatment of infertility.
1. Infertility (pulsatile) 2. Prostate cancer (continuous: use with flutamide) 3. Uterine fibroids

37. How are Sulfonamides employed clinically?
Beta lactams - inhibit cell wall synthesis - Bactericidal
Gram + - Gram - - Norcardia - Chlamydia
Resistant Gram - infections
Bleeding.

38. What is the category of drug names ending in - azine (e.g. Chlorpromazine)
Nifedipine - Verapamil - Diltiazem
Reversibly inhibits cyclooxygenase - mostly in CNS. Inactivated peripherally.
Phenothiazine (neuroleptic - antiemetic).
Antimetabolite derivative of 6- mercaptopurine that interferes with the metablolism and synthesis of nucleic acid.

39. What musculo - skeletal side effects in Adults are associated with Floroquinolones?
Tendonitis and Tendon rupture
Giant Roundworm (Ascaris) - Hookworm (Necator/Ancylostoma) - Pinworm (Enterobius)
- Disulfram & also sulfonylureas - metronidazole
- Hydralazine - Procainamide - INH - phenytoin

40. Antiarrhythmic class IC- toxicity?
Indomethacin is used to close a patent ductus arteriosus.
new arrhythmias - hypotension
proarrhythmic
Hormone synthesis inhibition (Gynecomastia) - Liver dysfunction (Inhibits CYP450) - Fever - Chills

41. MOA: Block protein synthesis at 50s subunit
- Metronidazole - certain cephalosporins - procarbazine - sulfonylureas
Beta lactams - inhibit cell wall synthesis - Bactericidal
Chloramphenicol - Erythromycin/macrolides - Lincomycin - Clindamycin - Streptogramins (quinupristin - dalfopristin)
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.

42. What is an additional side effect of Methicillin?
- Corticosteroids - heparin
1. Suppresses organ rejection after transplantation 2. Selected autoimmune disorders.
Primaquine
Interstitial nephritis

43. Mg+- clinical use?
all of them
Vibrio cholerae Acne Chlamydia Ureaplasma Urealyticum Mycoplasma pneumoniae Borrelia burgdorferi (Lyme's) Rickettsia Tularemia
effective in torsade de pointes and digoxin toxicity
1. Hydrocortisone 2. Predisone 3. Triamcinolone 4. Dexamethasone 5. Beclomethasone

44. What are three types of antacids and the problems that can result from their overuse?
hypertension - CHF - diabetic renal disease
Epinephrine
1. Aluminum hydroxide: constipation and hypophosphatemia 2. Magnesium hydroxide: diarrhea 3. Calcium carbonate: Hypercalcemia - rebound acid increase - All may cause hypokalemia
- Isoniazid

45. What are the clinical uses for 1st Generation Cephalosporins?
As an anticholinesterase it increases endogenous ACh and thus increases strength.
Gram + cocci - Proteus mirabilis - E. coli - Klebsiella pneumoniae (PEcK)
Blocks Peptide Bond formation at the 50S subunit - Bacteriostatic
alpha -1 > alpha -2; used as a pupil dilator - vasoconstrictor - and for nasal decongestion

46. What is the memory key for the action of Sildenafil (Viagra)?
Staphlococcus aureus and Clostridium difficile (pseudomembranous colitis)
Misoprostol is contraindicated in women of childbearing potential because it is an abortifacient.
Sildenafil fills the penis
1. Peptic ulcer 2. Gastritis 3. Esophageal reflux 4. Zollinger - Ellison syndrome

47. Why are the Sulfonylureas inactive in IDDM (type -1)?
Because they require some residual islet function.
Lidocaine - Mexiletine - Tocainide
- Tetracycline - amiodarone - sulfonamides
Reversibly inhibit cyclooxygenase (COX I and COX II). Block prostaglandin synthesis.

48. Which drug(s) cause this reaction: Focal to massive hepatic necrosis (4)?
Mebendazole/Thiabendazole - Pyrantel Pamoate
Oral treatment of superficial infections
- Halothane - Valproic acid - acetaminophen - Amantia phalloides
Small lipid - soluble molecule

49. Name some common Sulfonamides (4)
torsade de pointes
Sulfamethoxazole (SMZ) - Sulfisoxazole - Triple sulfas - Sulfadiazine
1. Taken daily 2. No protection against STDs 3. Raises triglycerides 4. Depression - weight gain - nausea - HTN 5. Hypercoagulable state
Pretreat with antihistamines and a slow infusion rate

50. Sotalol - toxicity?
Penicillin.
increase AP duration - increase ERP - increase QT interval - for use When other arrhythmics fail
torsade de pointes - excessive Beta block
- Glucagon