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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. Does Heparin have a long - medium - or short half life?
Short.
The COX-2 inhibitors should not have the corrosive effects of other NSAIDs on the gastrointestinal lining.
Neomycin
viral kinase

2. Which drug(s) cause this reaction: Hepatitis?
Beta 2 agonist; desired effect is the relaxation of bronchial smooth muscle (Beta 2). Use during acute exacerbation.
- Isoniazid
distal convoluted tubule (early)
constipation - flushing - edema - CV effects (CHF - AV block - sinus node depression) - and torsade de pointes (Bepridil)

3. What are two toxicities associated with Cyclosporine?
Misoprostol is a PGE1 analog that increases the production and secretion of the gastic mucous barrier.
Ceftriaxone
Norepinephrine
1. Predisposes to viral infections and lymphoma 2. Nephrotoxic (preventable with mannitol diuresis)

4. Ethacrynic Acid - mechanism?
Sotalol - Ibutilide - Bretylium - Amiodarone
not a sulfonamide - but action is the same as furosemide
Phenothiazine (neuroleptic - antiemetic).
troponin - tropomyosin system

5. ACE inhibitors - clinical use?
Epinephrine to treat anaphylaxis. Also useful if you have open angle glaucoma - asthma - or hypotension.
Small lipid - soluble molecule
hypertension - CHF - diabetic renal disease
- Lithium

6. What process does Zafirlukast interfere with?
Sulfonamides - Trimethoprim
Inhibit Ergosterol synthesis
Penicillin - Cephalosporins - Vancomycin - Aminoglycosides - Fluoroquinolones - Metronidazole
Leukotrienes increasing bronchial tone.

7. What type of patient should not take Misoprostol and why?
- N- acetylcystine
local anesthetic. CNS stimulation or depression. CV depression.
Inhibit Ergosterol synthesis
Misoprostol is contraindicated in women of childbearing potential because it is an abortifacient.

8. For Heparin What is the Lab value to monitor
compensatory tachycardia - fluid retention - lupus - like syndrome
aPTT (intrinsic pathway)
orthostatic and exercise hypotension - sexual dysfunction - diarrhea
- Infections - Trauma - Seizures - CO - Overdose - Metabolic - Alcohol (IT'S COMA)

9. What would be the effect on blood pressure with infusion of the alpha -2 agonist clonidine?
Botulinum
Binding to the presynaptic alpha 2 release modulating receptors
Paranteral (IV - SC)
Initially vasoconstriction would increase bp - but then it acts on central alpha -2 receptors to decrease adrenergic outflow resulting in decreased bp.

10. What antimuscarinic drug is useful for the tx of asthma
Ipratropium
1. Significant: nephrotoxicity 2. Peripheral neuropathy 3. Hypertension 4. Pleural effusion 5. Hyperglycemia.
INH: Injures Neurons and Hepatocytes
Binds 30S subunit and prevents attachment of aminoacyl - tRNA - Bacteriostatic

11. What are the clinical uses for 1st Generation Cephalosporins?
acts at the proximal convoluted tubule to inhibit carbonic anhydrase. Causes self - limited sodium bicarb diuresis and reduction of total body bicarb stores.
Gram + cocci - Proteus mirabilis - E. coli - Klebsiella pneumoniae (PEcK)
In treatment of malignant hyperthermia - due to concomitant use of halothane and succinylcholine. Also in neuroleptic malignant syndrome - a toxicity of antipsychotic drugs.
Hormone synthesis inhibition (Gynecomastia) - Liver dysfunction (Inhibits CYP450) - Fever - Chills

12. Adverse effects of Reserpine?
Triple Therapy' 2 Nucleoside RT Inhibitors with a Protease Inhibitor
acts at the proximal convoluted tubule to inhibit carbonic anhydrase. Causes self - limited sodium bicarb diuresis and reduction of total body bicarb stores.
Inhibt Assembly of new virus by Blocking Protease Enzyme
sedation - depression - nasal stuffiness - diarrhea

13. MOA: Block protein synthesis at 30s subunit
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
Hexamethonium is a nicotinic antagonist - and thus is a ganglionic blocker.
Disulfiram - like reaction with EtOH - Headache
Aminoglycosides - Tetracyclines

14. What is the category of drug names ending in - barbital (e.g. Phenobarbital)
Constant FRACTION eliminated per unit time.(exponential)
K+ wasting - metabolic alkalosis - hypotension - ototoxicity
Topical and Oral - for Oral Candidiasis (Thrush)
Babiturate.

15. What are three types of antacids and the problems that can result from their overuse?
1. Aluminum hydroxide: constipation and hypophosphatemia 2. Magnesium hydroxide: diarrhea 3. Calcium carbonate: Hypercalcemia - rebound acid increase - All may cause hypokalemia
Mechanism unknown; possibly inhibits gluconeogenesis and increases glycolysis; effect is to decrease serum glucose levels
vascular sm. Mus.: Nifedipine>Diltiazem>Verapamil
- S- phase anti - metabolite Pyr analogue - Colon - solid tumors - & BCC/ - Irreversible myelosuppression

16. How do you treat coma in the ER (4)?
- Tetracycline - amiodarone - sulfonamides
Prefers beta's at low doses - but at higher doses alpha agonist effects are predominantly seen.
Giant Roundworm (Ascaris) - Hookworm (Necator/Ancylostoma) - Pinworm (Enterobius)
- Airway - Breathing - Circulation - Dextrose (thiamine & narcan) - ABCD

17. How does dantrolene work?
- S- phase anti - metabolite folate analogue - Luk - Lymp - sarc - RA - & psoriasis / - Reversible myelosuppression
Inhibition of 50S peptidyl transferase - Bacteriostatic
- NaHCO3
Prevents the release of calcium from the sarcoplasmic reticulum of skeletal muscle.

18. What is the MOA of Polymyxins?
thiazides - amiloride
new arrhythmias - hypotension
Bind cell membrane - disrupt osmotic properties - Are Cationc - Basic and act as detergents
Inhibit steroid synthesis - used in the treatment of polycystic ovarian syndrome to prevent hirsutism.

19. What are nine findings of Iatrogenic Cushing's syndrome caused by glucocorticoid therapy?
Binding to the presynaptic alpha 2 release modulating receptors
Amphotericin B - Nystatin - Fluconazole/azoles
Dopamine
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

20. What is the mechanism of action of the thrombolytics?
Acts as a wide spectrum carbapenem
Only in limited amounts
Tubocurarine - atracurium - mivacurium - pancuronium - vecuronium - rapacuronium
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.)

21. How do we stop angina?
- Alkalating agent - NHL - Breast - ovary - & lung. - Myelosuppression - & hemorrhagic cystitis.
- B51Naloxone / naltrexone (Narcan)
GI upset
decrease myocardial O2 consumption by: 1- decreasing end diastolic volume 2- decreasing BP 3- decreasing HR 4- decreasing contractility 5- decreasing ejection time

22. Which drug(s) cause this reaction: Disulfram - like reaction (4) ?
Inhibits Viral DNA polymerase
- Metronidazole - certain cephalosporins - procarbazine - sulfonylureas
Hypersensitivity reactions
Nitrates

23. List the specific antidote for this toxin: Arsenic (all heavy metals)
Choline acetyltransferase
Delirium - Tremor - Nephrotoxicity
- Dimercaprol - succimer
Beta adrenergic receptors and Ca2+ channels (stimulatory)

24. What is used to reverse the action of Heparin?
Mycobacterium tuberculosis - the only agent used as solo prophylaxis against TB
Binds ergosterol - Disrupts fungal membranes
Protamine Sulfate is used for rapid reversal of heparinization (positively charged molecule that binds to negatively charged heparin).
Ipratropium

25. Will Hemicholinum affect the release of stored Ach during Cholinergic Stimulation
Ataxia - Dizziness - Slurred speech
impotence - asthma - CV effects (bradycardia - CHF - AV block) - CNS effects (sedation - sleep alterations)
No - hemicholinum block the uptake of Choline and thus Ach synthesis
Lovastatin - Pravastatin - Simvastatin - Atorvastatin

26. What are toxicities associated with Chloramphenicol?
Aplastic anemia (dose independent) - Gray Baby Syndrome
NO
Protease Inhibitors and Reverse Transcriptase Inhibitors
They activate the ciliary muscle of the eye (open angle) and pupillary sphincter (narrow angle).

27. How does botulinum toxin result in respiratory arrest?
The only local anesthetic with vasoconstrictive properties.
Hypersensitivity reactions
Prevents the release of ACh - Which results in muscle paralysis.
Pentavalent Antimony

28. What is the clinical use for Ampicillin and Amoxicillin?
1. Tolbutamide 2. Chlorpropamide 3. Glyburide 4. Glipizide
Extended spectrum penicillin: certain Gram + bacteria and Gram - rods
Inhibits Viral DNA polymerase
Nonspecific beta - agonist; desired effect is the relaxation of bronchial smooth muscle (Beta 2). Adverse effect is tachycardia (Beta 1).

29. What populations are Floroquinolones contraindicated in? Why?
Small lipid - soluble molecule
It must be Phosphorylated by Viral Thymidine Kinase
- Sulfonamides - furosemide - methicillin - rifampin - NSAIDS (ex. ASA)
Pregnant women - Children; because animal studies show Damage to Cartilage

30. Which receptors does phenylephrine act upon?
Peptic ulcer disease.
for RSV
Same as penicillin. Act as narrow spectrum antibiotics
alpha -1 > alpha -2; used as a pupil dilator - vasoconstrictor - and for nasal decongestion

31. Resistance mechanisms for Vancomycin
Ganciclovir is more toxic to host enzymes
Terminal D- ala of cell wall replaced with D- lac; Decreased affinity
No
Imipenem

32. Why is reserpine effective in treating HTN?
Inhibits CMV DNA polymerase
Reserpine inhibits dopamine transport into vesicles - attenuating its conversion to NE by dopamine beta - hydroxylase.
To inhibit renal Dihydropeptidase I and decrease Imipenem inactivation in the renal tubules
Disulfiram - like reaction with EtOH - Headache

33. What drug is given for Pneumocystis carinii prophylaxis?
Pentamidine
Benzodiazepine.
Rifampin
Interstitial nephritis

34. Antiarrhythmic Class III- effects?
Inhibit steroid synthesis - used in the treatment of polycystic ovarian syndrome to prevent hirsutism.
increase AP duration - increase ERP - increase QT interval - for use When other arrhythmics fail
- NaHCO3
Amphotericin B - Nystatin - Fluconazole/azoles

35. What are three possible toxicities of NSAID usage?
- Barbiturates - phenytoin - carbamazipine - rifampin - griseofulvin - quinidine
1. Renal damage 2. Aplastic anemia 3. GI distress
Short.
Gram + cocci - Proteus mirabilis - E. coli - Klebsiella pneumoniae (PEcK)

36. What are five advantages of Oral Contraceptives (synthetic progestins - estrogen)?
Inhibit intestinal bursh border Alpha - glucosidases; delayed hydrolysis of sugars and absorption of sugars leading to decresed postprandial hyperglycemia.
Inhibits Viral DNA polymerase
torsade de pointes
1. Reliable (<1% failure) 2. Lowers risk of endometrial and ovarian cancer 3. Decreased incidence of ectopic pregnancy 4. Lower risk of pelvic infections 5. Regulation of menses

37. What are Methicillin - Nafcillin - and Dicloxacillin used for clinically?
Yes - it does not cross the placenta.
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.
Staphlococcus aureus
- acetylation - glucuron. - & sulfation - Conjugation - Polar product

38. Ganciclovir associated toxicities?
proximal convoluted tubule - thin descending limb - and collecting duct
1. Hot flashes 2. Ovarian enlargement 3. Multiple simultaneous pregnancies 4. Visual disturbances
- N- acetylcystine
Leukopenia - Neutropenia - Thrombocytopenia - Renal toxicity

39. What is a common side effect of Colchicine used to treat acute gout - especially When given orally?
Blocks Peptide Bond formation at the 50S subunit - Bacteriostatic
GI side effects. (Indomethacin is less toxic - more commonly used.)
impotence - asthma - CV effects (bradycardia - CHF - AV block) - CNS effects (sedation - sleep alterations)
Ototoxicity - Hypokalemia - Dehydration - Allergy (sulfa) - Nephritis (interstitial) - Gout

40. What are three clinical uses of the NSAIDs?
Diuresis in pateints with sulfa allergy
1. Antipyretic 2. Analgesic 3. Anti - inflammatory
- Tetracycline - amiodarone - sulfonamides
- Upper respiratory tract infections - pneumonias - STDs: Gram+ cocci (streptococcal infect in pts allergic to penicillin) - Mycoplasma - Legionella - Chlamydia - Neisseria

41. Antiarrhythmic class IV- effects?
Decreased uptake or Increased transport out of cell
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
decrease conduction velocity - increase ERP - increase PR interval
1. Antipyretic 2. Analgesic 3. Anti - inflammatory 4. Antiplatelet drug.

42. MOA for Penicillin (3 answers)?
- Sulfonamides - INH - ASA - Ibuprofen - primaquine - nitrofurantoin /- pyrimethamine - chloramphenicol
Inhibits CMV DNA polymerase
Binds Ergosterol - forms Membrane Pores that Disrupt Homeostatis
1)Binds penicillin - binding proteins 2) Blocks transpeptidase cross - linking of cell wall 3) Activates autolytic enzymes

43. What are the clinical uses for 2nd Generation Cephalosporins?
Gram + cocci - Haemophilus influenza - Enterobacter aerogenes - Neisseria species - P. mirabilis - E. coli - K. pneumoniae - Serratia marcescens ( HEN PEcKS )
Activates cholinergic receptors on bladder and bowel smooth muscle - alleviating post - op and neurogenic ileus and urinary retention.
Succinylcholine
Pseudomembranous colitis (C. difficile) - fever - diarrhea

44. What is the category - mechanism of action - and effect of Ipratroprium in Asthma treatment?
Muscarinic antagonist; competatively blocks muscarinic receptors - preventing bronchoconstriction.
- Alkalinize urine & dialysis
It affects beta receptors equally and is used in AV heart block (rare).
Blocks viral penetration/uncoating; may act to buffer the pH of the endosome

45. Name two bile acid resins.
Na/K ATPase
Triple Therapy' 2 Nucleoside RT Inhibitors with a Protease Inhibitor
cholestyramine - colestipol
Chronic anticoagulation.

46. How does angiotensin II affect NE release?
Cell membrane Ca2+ channels of cardiac sarcomere
It acts presynaptically to increase NE release.
- Sulfonamides - furosemide - methicillin - rifampin - NSAIDS (ex. ASA)
Non - Nucleosides

47. Name the steps in drug approval(4)?
- Phase I (clinical tests) - Phase II - Phase III - PhaseIV (surveillance)
Reversibly inhibits cyclooxygenase - mostly in CNS. Inactivated peripherally.
Hemolysis (if G6PD deficient) - Neurotoxicity - Hepatotoxicity - SLE- like syndrome
Leukopenia - Neutropenia - Thrombocytopenia - Renal toxicity

48. How is Leishmaniasis treated?
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
Pentavalent Antimony
thiazides - amiloride
Rash - Pseudomembranous colitis

49. What are two toxicities of the Glitazones?
troponin - tropomyosin system
1. Weight gain 2. Hepatotoxicity (troglitazone)
Quinolones
- EDTA - dimercaprol - succimer - & penicillamine

50. Toxic effects of TMP include?
for RSV
Finasteride inhibits 5 Alpha - reductase - this decreases the conversion of testosterone to dihydrotestosterone - useful in BPH
Megaloblastic anemia - Leukopenia - Granulocytopenia
1. Significant: nephrotoxicity 2. Peripheral neuropathy 3. Hypertension 4. Pleural effusion 5. Hyperglycemia.