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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. Oral Penicillin
- Alkalating agents+cisplatin - Doxorubicin+Dactinomycin - Bleomycin - Etoposide
Binds to the Pyrophosphate Binding Site of the enzyme
Penicillin - V
No

2. For Warfarin What is the Duration of action
Acute (hours)
Chronic (weeks or months)
Penicillin - G
1. Peptic ulcer 2. Gastritis 3. Esophageal reflux 4. Zollinger - Ellison syndrome

3. Amiodarone - toxicity?
Edrophonium
pulmonary fibrosis - corneal deposits - hepatotoxicity - skin deposits resulting in photodermatitis - neurologic effects - consitpation - CV (bradycardia - heart block - CHF) - and hypo - or hyperthyroidism.
GI intolerance (nausea - diarrhea) - Hyperglycemia - Lipid abnormalities - Thrombocytopenia (Indinavir)
Interstitial nephritis

4. Adverse effects of Minoxidil?
Penicillin - Cephalosporins - Vancomycin - Aminoglycosides - Fluoroquinolones - Metronidazole
Reserpine inhibits dopamine transport into vesicles - attenuating its conversion to NE by dopamine beta - hydroxylase.
Sucralfate cannot work in the presence of antacids or H2 blockers because it requires an acidic environment to polymerize.
hypertrichosis - pericardial effusion - reflex tachycardia - angina - salt retention

5. Describe first - order kinetics?
Modification via Acetylation
Constant FRACTION eliminated per unit time.(exponential)
Activates cholinergic receptors on bladder and bowel smooth muscle - alleviating post - op and neurogenic ileus and urinary retention.
Inhibit steroid synthesis - used in the treatment of polycystic ovarian syndrome to prevent hirsutism.

6. Which of epi - norepi - or isoproterenol results in bradycardia?
Binds 30S subunit and prevents attachment of aminoacyl - tRNA - Bacteriostatic
Norepinephrine
Bind cell membrane - disrupt osmotic properties - Are Cationc - Basic and act as detergents
It acts presynaptically to increase NE release.

7. Sotalol - toxicity?
- N- acetylcystine
Inhibits cell wall synthesis ( binds to PBP3). A monobactam
is resistant
torsade de pointes - excessive Beta block

8. What are the clinical uses for Aztreonam?
- Shifts the curve to the right - increases Km
Diuresis in pateints with sulfa allergy
Gram - rods: Klebsiella species - Pseudomonas species - Serratia species
Heparin catalyzes the activation of antithrombin III.

9. What are signs of Sildenafil (Viagra) toxicity?
1) Chloramphenical = bacteriostatic 2) Erythromycin = bacteriostatic 3) Lincomycin = bacteriostatic 4)cLindamycin = bacteriostatic
Headache - flushing - dyspepsia - blue - green color vision.
Ld= (CpxVd)/F Cp=plasma conc. F= Bioaval.
1. Antipyretic 2. Analgesic 3. Anti - inflammatory

10. What are three clinical uses of the NSAIDs?
1. Antipyretic 2. Analgesic 3. Anti - inflammatory
- Methotrexate - 5 FU - 6 mercaptopurine
viral kinase
CL= (rate of elimination of drug/ Plasma drug conc.)

11. Resistance mechanisms for Chloramphenicol
Modification via Acetylation
1. Suppresses organ rejection after transplantation 2. Selected autoimmune disorders.
Phosphorylation by a Viral Kinase
- Normalize K+ - Lidocaine - & Anti - dig Mab

12. Why is there a drop in systolic - mean - and diastolic bp with infusion of isoproterenol?
1. Weight gain 2. Hepatotoxicity (troglitazone)
GI upset - Superinfections - Skin rashes - Headache - Dizziness
DOC in diagnosing and abolishing AV nodal arrhythmias
Stimulating beta receptors stimulates heart rate - but beta receptor induced vasodilation reduces peripheral resistance.

13. Can Warfarin be used during pregnancy?
Amphotericin B - Nystatin - Fluconazole/azoles
1) Aminoglycosides = bactericidal 2) Tetracyclines = bacteriostatic
No - warfarin - unlike heparin - can cross the placenta.
Sildenafil fills the penis

14. What are two processes Corticosteroids inhibit leading to decreased inflammation?
1. Phospholipase A2 is prevented from releasing arachidonic acid 2. Decreases protein synthesis thus lowering amount of Cyclooxygenase enzymes
ACIDazolamide' causes acidosis
Rifampin - Ethambutol - Streptomycin - Pyrazinamide - Isoniazid (INH)
- Quinidine - quinine

15. What are the clinical uses for Ticlopidine - Clopidogrel?
- Atropine & pralidoxime
Acute coronary syndrome; coronary stenting. Decreases the incidence or recurrence of thrombotic stroke.
- Sulfonamides - INH - ASA - Ibuprofen - primaquine - nitrofurantoin /- pyrimethamine - chloramphenicol
Delirium - Tremor - Nephrotoxicity

16. What is the possible mechanism and effect of Metformin in treating diabetes?
Mechanism unknown; possibly inhibits gluconeogenesis and increases glycolysis; effect is to decrease serum glucose levels
Acute coronary syndrome; coronary stenting. Decreases the incidence or recurrence of thrombotic stroke.
Modification via Acetylation
GI disturbances.

17. K+ sparing diuretics - toxicity?
hyperkalemia - endocrine effects (gynecomastia - anti - androgen)
GI discomfort - Acute cholestatic hepatitis - Eosinophilia - Skin rashes
- Chloramphenicol
Tendonitis and Tendon rupture

18. What is the major side effect for Carbenicillin - Piperacillin - and Ticarcillin?
YES
Tetracycline - Doxycycline - Demeclocycline - Minocycline
Hypersensitivity reactions
Amphetamine and Ephedrine

19. List the specific antidote for this toxin: Amphetamine
- Ammonium Chloride
Diuresis in pateints with sulfa allergy
Antifungal.
Beta 2 agonist; used as a long - acting agent for prophylaxis. Adverse effects are tremor and arrhythmia.

20. Common side effects associated with Clindamycin include?
Norepinephrine (Alpha1 -2 and beta 1)
hypertension - angina - arrhythmias
proximal convoluted tubule - thin descending limb - and collecting duct
Pseudomembranous colitis (C. difficile) - fever - diarrhea

21. Side effects of Isoniazid (INH)?
Hemolysis (if G6PD deficient) - Neurotoxicity - Hepatotoxicity - SLE- like syndrome
proximal convoluted tubule
Acute coronary syndrome; coronary stenting. Decreases the incidence or recurrence of thrombotic stroke.
Prevents the release of Ca from SR of skeletal muscle

22. What is the memory key involving the '4 R's of Rifampin?'
Prevention of NSAID- induced peptic ulcers - maintains a PDA.
Pituitary hormone.
1. RNA pol inhibitor 2. Revs up P450 3. Red/orange body fluids 4. Rapid resistance if used alone
Terminal D- ala of cell wall replaced with D- lac; Decreased affinity

23. How do we stop angina?
decrease myocardial O2 consumption by: 1- decreasing end diastolic volume 2- decreasing BP 3- decreasing HR 4- decreasing contractility 5- decreasing ejection time
1. Buffalo hump 2. Moon facies 3. Truncal obesity 4. Muscle wasting 5. Thin skin 6. Easy bruisability 7. Osteoporosis 8. Adrenocortical atrophy 9. Peptic ulcers
- N- acetylcystine
- Vitamin K & fresh frozen plasma

24. What are the clinical indications for neostigmine?
None. No - because atropine would block the postganglionic muscarinic receptors involved in sweat gland stimulation.
Post - op and neurogenic ileus and urinary retention - myasthenia gravis - and reversal of neuromuscular junction blockade (post - op) through anticholinesterase activity.
Protamine sulfate
- Flumazenil

25. Describe Phase I metabolism in liver(3)?
- reduction - oxy - & hydrolysis - H2O sol. Polar product - P450
cyanide toxicity (releases CN)
- inhibits HGPRT (pur. Syn.) - Luk - Lymph
- polymyxins

26. Antiarrhythmic class IV- primary site of action?
Ibuprofen - Naproxen - and Indomethacin
AV nodal cells
loop diuretics - spironolactone
Nevirapine - Delavirdine

27. Antiarrhythmic class IC- toxicity?
proarrhythmic
Enterobacter
Hypokalemic metabolic alkalosis - hyponatremia - hyperGlycemia - hyperLipidemia - hyperUricemia - hyperCalcemia - sulfa allergy.
To inhibit renal Dihydropeptidase I and decrease Imipenem inactivation in the renal tubules

28. List the specific antidote for this toxin: Salicylates
- Alkalinize urine & dialysis
- Sulfonamides - furosemide - methicillin - rifampin - NSAIDS (ex. ASA)
Hemolysis (if G6PD deficient) - Neurotoxicity - Hepatotoxicity - SLE- like syndrome
cyanide toxicity (releases CN)

29. What microorganisms are Aminoglycosides ineffective against?
Norepinephrine (Alpha1 -2 and beta 1)
Anaerobes
Mg = Must go to the bathroom.
Lovastatin - Pravastatin - Simvastatin - Atorvastatin

30. What is the category of drug names ending in - ipramine (e.g. Imipramine)
Inhibits IMP Dehydrogenase (competitively) - and therefore blocks Guanine Nucleotide synthesis
- Ammonium Chloride
depresses ectopic pacemakers - especially in digoxin toxicity
Tricyclic antidepressant.

31. Are penicillinase resistant
Methicillin - Nafcillin - and Dicloxacillin
1. Addison's disease 2. Inflammation 3. Immune suppression 4. Asthma
- partial agonist can have increased - decreased - /A21or equal potency as full agonist. - Potency is an independent factor.
NE increases bp - Which stimulates baroreceptors in the carotid sinus and the aorta. The CNS signals through vagal stimulation to decrease heart rate.

32. Ryanodine - site of action?
Prevents the release of calcium from the sarcoplasmic reticulum of skeletal muscle.
first dose orthostatic hypotension - dizziness - headache
blocks SR Ca2+ channels
Saquinavir - Ritonavir - Indinavir - Nelfinavir

33. What is the memory key for the action of Sildenafil (Viagra)?
prevention of nodal arrhythmias (SVT)
Spironolactone - Triamterene - Amiloride (the K+ STAys)
Sildenafil fills the penis
- Sulfonamides - INH - ASA - Ibuprofen - primaquine - nitrofurantoin /- pyrimethamine - chloramphenicol

34. What is the formula for Volume of distribution (Vd)
Hydralazine and Minoxidil
1. RNA pol inhibitor 2. Revs up P450 3. Red/orange body fluids 4. Rapid resistance if used alone
Vd= (Amt. of drug in body/ Plasma drug conc.)
Hexamethonium is a nicotinic antagonist - and thus is a ganglionic blocker.

35. Hydrochlorothiazide - clinical use?
Ibuprofen - Naproxen - and Indomethacin
HTN - CHF - calcium stone formation - nephrogenic DI.
Milk or Antacids - because divalent cations inhibit Tetracycline absorption in the gut
Bactericidal for: Gram + rod and cocci - Gram - cocci - and Spirochetes

36. What is the MOA for Carbenicillin - Piperacillin - and Ticarcillin?
Prevents the release of Ca from SR of skeletal muscle
Ataxia - Dizziness - Slurred speech
Same as penicillin. Extended spectrum antibiotics
Binds ergosterol - Disrupts fungal membranes

37. For Heparin What is the Duration of action
Those patients who are taking nitrates.
Corticosteroids; prevent production of leukotrienes from arachodonic acid by blocking phospholipase A2. Drugs of choice in a patient with status asthmaticus (in combination with albuterol.)
Acute (hours)
It inhibits release of NE.

38. What are the four conditions in Which Omeprazole - Lansoprazole is used?
1. Peptic ulcer 2. Gastritis 3. Esophageal reflux 4. Zollinger - Ellison syndrome
Methylxanthine.
Pentavalent Antimony
HSV - VZV - EBV - Mucocutaneous and Genital Herpes Lesions - Prophylaxis in Immunocompromised pts

39. ___________ are Teratogenic
Competitive inibitor of progestins at progesterone receptors.
Finasteride inhibits 5 Alpha - reductase - this decreases the conversion of testosterone to dihydrotestosterone - useful in BPH
Aminoglycosides
- S- phase anti - metabolite folate analogue - Luk - Lymp - sarc - RA - & psoriasis / - Reversible myelosuppression

40. Decrease Digitoxin dose in renal failure?
Phase 1 = prolonged depolarization - no antidote - effect potentiated by anticholinesterase; Phase 2 = repolarized but blocked - an anticholinesterase is the antidote for this phase.
dizziness - flushing - constipation (verapamil) - nausea
NO
cross - allergenic

41. Ca2+ sensitizers'- site of action?
all of them
Protease Inhibitors and Reverse Transcriptase Inhibitors
hypertrichosis - pericardial effusion - reflex tachycardia - angina - salt retention
troponin - tropomyosin system

42. What is the MOA for the Fluoroquinolones?
Botulinum
Inhibits cell wall synthesis ( binds to PBP3). A monobactam
Inhibit DNA Gyrase (topoisomerase II) - Bactericidal
- Physostigmine salicylate

43. What is the effect of TCA's on the adrenergic nerve?
- Isoniazid
They inhibit reuptake of NE at the nerve terminal (as does cocaine).
Aminoglycosides
Rapid (seconds)

44. What is the mechanism of action of the Sulfonylureas?
- Weak Acids>Alkinalize urine(CO3) to remove more - Weak bases>acidify urine to remove more
1. Addison's disease 2. Inflammation 3. Immune suppression 4. Asthma
hyperkalemia - endocrine effects (gynecomastia - anti - androgen)
Close K+ channels in Beta - cell membrane leading to cell depolarization causing insulin release triggered by increase in Calcium ion influx.

45. For Warfarin What is the Route of administration
1. Bleeding 2. Thrombocytopenia 3. Drug - drug interactions
- Steroids - Tamoxifen
Oral
Similar to cyclosporine; binds to FK- binding protein - inhibiting secretion of IL-2 and other cytokines.

46. Which drug(s) cause this reaction: Photosensitivity(3)?
Reversibly inhibit cyclooxygenase (COX I and COX II). Block prostaglandin synthesis.
Minor hepatotoxicity - Drug interactions (activates P450)
fetal renal toxicity - hyperkalemia - Cough - Angioedema - Proteinuria - Taste changes - hypOtension - Pregnancy problems - Rash - Increased renin - Lower Angiotensin II (CAPTOPRIL)
- Tetracycline - amiodarone - sulfonamides

47. What sympathomimetic would you not prescribe for hypotension in a pt with renal artery sclerosis.
Norepinephrine (Alpha1 -2 and beta 1)
Penicillin - Ampicillin - Ticarcillin - Pipercillin - Imipenem - Aztreonam - Cephalosporins
Post - op and neurogenic ileus and urinary retention - myasthenia gravis - and reversal of neuromuscular junction blockade (post - op) through anticholinesterase activity.
Gram + cocci - Gram - rods - and Anerobes

48. Is resistant to penicillinase?
torsade de pointes
- MT polymerization stabilizer - Ovarian & breast CA - Myelosupperession & hypersensitivity.
Imipenem
NE acts presynaptically on alpha -2 receptors to inhibit its own release. ACh also acts presynaptically through M1 receptors to inhibit NE release.

49. Which antimuscarinic agents are used in producing mydriasis and cycloplegia?
Yes
atropine - homatropine - tropicamide
cholestyramine - colestipol
anuria - CHF

50. What drugs target anticholinesterase
Neostigmine - pyridostigmine edrophonium - physostigmine echothiophate
They activate the ciliary muscle of the eye (open angle) and pupillary sphincter (narrow angle).
Norepinephrine
1. Aluminum hydroxide: constipation and hypophosphatemia 2. Magnesium hydroxide: diarrhea 3. Calcium carbonate: Hypercalcemia - rebound acid increase - All may cause hypokalemia