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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. Acetaminophen has What two clinical uses and lacks What one clinical use of the NSAIDs?
Chronic anticoagulation.
hyperkalemia - endocrine effects (gynecomastia - anti - androgen)
Acetaminophen has antipyretic and analgesic properties - but lacks anti - inflammatory properties.
- Phase I (clinical tests) - Phase II - Phase III - PhaseIV (surveillance)

2. What is a common drug interaction associated with Griseofulvin?
cortical collecting tubule
Increases coumadin metabolism
Clavulanic acid
first dose orthostatic hypotension - dizziness - headache

3. List the mechanism - clinical use - & toxicity of Bleomycin.
- DNA intercalator - testicular & lymphomas - Pulmonary fibrosis mild myelosuppression.
- polymyxins
Digoxin=urinary Digitoxin=biliary
Staphlococcus aureus

4. How do the Protease Inhibitors work?
Inhibt Assembly of new virus by Blocking Protease Enzyme
Staphlococcus aureus
Carbachol - pilocarpine - physostigmine - echothiophate
None. No - because atropine would block the postganglionic muscarinic receptors involved in sweat gland stimulation.

5. Esmolol - short or long acting?
Phosphorylation by a Viral Kinase
- S- phase anti - metabolite folate analogue - Luk - Lymp - sarc - RA - & psoriasis / - Reversible myelosuppression
hyperchloremic metabolic acidosis - neuropathy - NH3 toxicity - sulfa allergy
very short acting

6. Describe the MOA of Interferons (INF)
GI distress - Skin rash - and Seizures at high plasma levels
Giardiasis - Amoebic dysentery (E. histolytica) - Bacterial vaginitis (Gardnerella vaginalis) - Trichomonas
is resistant
Glycoproteins from leukocytes that block various stages of viral RNA and DNA synthesis

7. Antiarrhythmic class II- effects?
decrease the slope of phase 4 - increase PR interval (the AV node is particularly sensitive)
Gram + cocci - Proteus mirabilis - E. coli - Klebsiella pneumoniae (PEcK)
1. Heavy bleeding 2. GI effects (n/v - anorexia) 3. Abdominal pain
Paranteral (IV - SC)

8. Clinical use of Isoniazid (INH)?
Does not cross
Mebendazole/Thiabendazole - Pyrantel Pamoate
Mycobacterium tuberculosis - the only agent used as solo prophylaxis against TB
Teratogenic - Carcinogenic - Confusion - Headaches

9. While at a tail gait party - you bite into a sandwich that a yellow jacket is also enjoying. Knowing your allergy to this creature - What should you do?
Sucralfate cannot work in the presence of antacids or H2 blockers because it requires an acidic environment to polymerize.
1. Taken daily 2. No protection against STDs 3. Raises triglycerides 4. Depression - weight gain - nausea - HTN 5. Hypercoagulable state
Epinephrine to treat anaphylaxis. Also useful if you have open angle glaucoma - asthma - or hypotension.
They inhibit reuptake of NE at the nerve terminal (as does cocaine).

10. What is the MOA for Methicillin - Nafcillin - and Dicloxacillin?
CL= (rate of elimination of drug/ Plasma drug conc.)
Vd= (Amt. of drug in body/ Plasma drug conc.)
Same as penicillin. Act as narrow spectrum antibiotics
H2 antagonist

11. Antiarrhythmic class IB- clinical uses?
hyperchloremic metabolic acidosis - neuropathy - NH3 toxicity - sulfa allergy
post MI and digitalis induced arrhythmias
Prevents release of mediators from mast cells. Effective only for the prophylaxis of asthma. Not effective during an acute attack.
Initially vasoconstriction would increase bp - but then it acts on central alpha -2 receptors to decrease adrenergic outflow resulting in decreased bp.

12. Ethacrynic Acid - clinical use?
thiazides - amiloride
Diuresis in pateints with sulfa allergy
- Flumazenil
nausea - headache - lupus - like syndrome - reflex tachycardia - angina - salt retention

13. Why would a patient with cog - wheel rigidity and a shuffling gait be given benztropine?
Hypokalemic metabolic alkalosis - hyponatremia - hyperGlycemia - hyperLipidemia - hyperUricemia - hyperCalcemia - sulfa allergy.
Parkinson patients benefit from antimuscarinic agents through its inhibitory action within the indirect pathway.
proximal convoluted tubule
Inhibits reabsorption of uric acid.

14. What is the mechanism of action of Omeprazole - Lansoprazole?
Terminal D- ala of cell wall replaced with D- lac; Decreased affinity
Inhibits Viral DNA polymerase
Verapamil - Diltiazem - Bepridil
Irreversibly inhibits H+/K+ ATPase in stomach parietal cells.

15. MOA: Block nucleotide synthesis
Digitoxin 70% Digoxin 20-40%
1. Hot flashes 2. Ovarian enlargement 3. Multiple simultaneous pregnancies 4. Visual disturbances
Sulfonamides - Trimethoprim
ACE inhibitor.

16. Adverse effects of Hydrochlorothiazide?
hypokalemia - slight hyperlipidemia - hyperuricemia - lassitude - hypercalcemia - hyperglycemia
Reversibly inhibits cyclooxygenase - mostly in CNS. Inactivated peripherally.
Buy AT 30 - CELL at 50'
Neutropenia

17. What conditions are treated with Metronidazole?
Aminoglycosides - Tetracyclines
Giardiasis - Amoebic dysentery (E. histolytica) - Bacterial vaginitis (Gardnerella vaginalis) - Trichomonas
WEPT: Warfarin affects the Extrinsic pathway and prolongs the PT.
Misoprostol is a PGE1 analog that increases the production and secretion of the gastic mucous barrier.

18. What are three possible complications of Heparin therapy?
Neutropenia (ticlopidine); reserved for those who cannot tolerate aspirin.
1. Bleeding 2. Thrombocytopenia 3. Drug - drug interactions
Verapamil - Diltiazem - Bepridil
Increased systolic and pulse pressure - decreased diastolic pressure - and little change in mean pressure.

19. What is the effect of epinephrine infusion on bp and pulse pressure?
Depolymerizes microtubules - impairing leukocyte chemotaxis and degranulation.
Antimetabolite derivative of 6- mercaptopurine that interferes with the metablolism and synthesis of nucleic acid.
1.Gram - rods of the Urinary and GI tracts (including Pseudomonas) 2.Neisseria 3. Some Gram + organisms
Increased systolic and pulse pressure - decreased diastolic pressure - and little change in mean pressure.

20. Secretion of What drug is inhibited by Probenacid used to treat chronic gout?
decrease myocardial O2 consumption by: 1- decreasing end diastolic volume 2- decreasing BP 3- decreasing HR 4- decreasing contractility 5- decreasing ejection time
fetal renal damage - hyperkalemia - Cough - Angioedema - Proteinuria - Taste changes - hypOtension - Pregnancy problems - Rash - Increased renin - Lower Angiotensin II (CAPTOPRIL)
Penicillin.
proarrhythmic

21. Digoxin v. Digitoxin: excretion?
Digoxin=urinary Digitoxin=biliary
proximal convoluted tubule - thin descending limb - and collecting duct
Anaerobic infections (e.g. - B. fragilis - C. perfringens)
1. Bleeding 2. Thrombocytopenia 3. Drug - drug interactions

22. Specifically - How does Foscarnet inhibit viral DNA pol?
Binds to the Pyrophosphate Binding Site of the enzyme
Resistant Gram - infections
Beta -2 agonist.
Binds ergosterol - Disrupts fungal membranes

23. Can Warfarin be used during pregnancy?
fetal renal toxicity - hyperkalemia
- Ammonium Chloride
Zidovudine (AZT) - Didanosine (ddI) - Zalcitabine (ddC) - Stavudine (d4T) - Lamivudine (3TC)
No - warfarin - unlike heparin - can cross the placenta.

24. What are the clinical uses for Aztreonam?
Gram - rods: Klebsiella species - Pseudomonas species - Serratia species
Albuterol - tertbutaline
Oral treatment of superficial infections
GI intolerance (nausea - diarrhea) - Hyperglycemia - Lipid abnormalities - Thrombocytopenia (Indinavir)

25. Which drug(s) cause this reaction: Neuro and Nephrotoxic?
Gemfibrozil - Clofibrate
Rifampin - Ethambutol - Streptomycin - Pyrazinamide - Isoniazid (INH)
- polymyxins
- Ammonium Chloride

26. What is the mechanism of Azathioprine?
Amphotericin B - Nystatin - Fluconazole/azoles
- Flumazenil
Antimetabolite derivative of 6- mercaptopurine that interferes with the metablolism and synthesis of nucleic acid.
- acetylation - glucuron. - & sulfation - Conjugation - Polar product

27. Name five Antiarrhythmic drugs in class II?
Bacitracin - Vancomycin
Digitoxin>95% Digoxin 75%
propanolol - esmolol - metoprolol - atenolol - timolol
Keratin containing tissues - e.g. - nails

28. What are two Glitazones?
orthostatic and exercise hypotension - sexual dysfunction - diarrhea
GI discomfort - Acute cholestatic hepatitis - Eosinophilia - Skin rashes
Ceftriaxone
1. Pioglitazone 2. Rosiglitazone.

29. Adverse effects of beta - blockers?
Amphetamine and Ephedrine
Methicillin - Nafcillin - and Dicloxacillin
Aplastic anemia (dose independent) - Gray Baby Syndrome
impotence - asthma - CV effects (bradycardia - CHF - AV block) - CNS effects (sedation - sleep alterations)

30. What is the MOA for Ampicillin and Amoxicillin?
Same as penicillin. Extended spectrum antibiotics
cinchonism: HA - tinnitus - thrombocytopenia - torsade de pointes due to increased QT interval
Decrease the production of leukotrienes and protaglandins by inhibiting phospholipase A2 and expression of COX-2.
Prevention of NSAID- induced peptic ulcers - maintains a PDA.

31. What are two mechanisms of action of Propythiouracil?
- Protamine
Inhibits organification and coupling of thyroid hormone synthesis. Also decreases peripheral conversion of T4 to T3.
vasodilator - increases cGMP to induce smooth muscle relaxation (arterioles>veins; afterload reduction)
HSV - VZV - EBV - Mucocutaneous and Genital Herpes Lesions - Prophylaxis in Immunocompromised pts

32. K+ sparing diuretics - toxicity?
Those patients who are taking nitrates.
Inhibits reabsorption of uric acid.
hyperkalemia - endocrine effects (gynecomastia - anti - androgen)
cardiac depression - peripheral edema - flushing - dizziness - constipation

33. What additional side effects exist for Ampicillin?
Lipoxygenase
Constant FRACTION eliminated per unit time.(exponential)
Rash - Pseudomembranous colitis
- Clindamycin

34. What is the lab value used to monitor the effectiveness of Heparin therapy?
Neostigmine - pyridostigmine edrophonium - physostigmine echothiophate
- Sulfonamides - INH - ASA - Ibuprofen - primaquine - nitrofurantoin /- pyrimethamine - chloramphenicol
Buy AT 30 - CELL at 50'
The PTT.

35. What effect would atropine have on a patient with peptic ulcer disease?
Ototoxicity - Hypokalemia - Dehydration - Allergy (sulfa) - Nephritis (interstitial) - Gout
Local anesthetic.
Theoretically it could be used to block the cephalic phase of acid secretion (vagal stimulation).
Binds 30S subunit and prevents attachment of aminoacyl - tRNA - Bacteriostatic

36. ACE inhibitors - toxicity?
hypertension - CHF - diabetic renal disease
aPTT (intrinsic pathway)
fetal renal damage - hyperkalemia - Cough - Angioedema - Proteinuria - Taste changes - hypOtension - Pregnancy problems - Rash - Increased renin - Lower Angiotensin II (CAPTOPRIL)
Close K+ channels in Beta - cell membrane leading to cell depolarization causing insulin release triggered by increase in Calcium ion influx.

37. Which drug(s) cause this reaction: Tardive dyskinesia?
- Antipsychotics
- EDTA - dimercaprol - succimer - & penicillamine
AZT
dry mouth - sedation - severe rebound hypertension

38. Adverse effects of Nifedipine - verapamil?
Topical and Oral - for Oral Candidiasis (Thrush)
dizziness - flushing - constipation (verapamil) - nausea
Ataxia - Dizziness - Slurred speech
Those patients who are taking nitrates.

39. Are not penicillinase resistant
Yes
- Ethanol - dialysis - & fomepizole
Carbenicillin - Piperacillin - and Ticarcillin
- Tetracycline - amiodarone - sulfonamides

40. What are the clinical uses for 2nd Generation Cephalosporins?
compensatory tachycardia - fluid retention - lupus - like syndrome
Beta 2 agonist; used as a long - acting agent for prophylaxis. Adverse effects are tremor and arrhythmia.
Diarrhea - Urination - Miosis - Bronchospasm - Bradycardia - Excitation of skeletal muscle and CNS - Lacrimation - Sweating - and Salivation = DUMBBELS; also abdominal cramping
Gram + cocci - Haemophilus influenza - Enterobacter aerogenes - Neisseria species - P. mirabilis - E. coli - K. pneumoniae - Serratia marcescens ( HEN PEcKS )

41. Beta Blockers - CV toxicity?
bradycardia - AV block - CHF
Acetylates and irreversibly inhibits cyclooxygenase (COX I and COX II) to prevent the conversion of arachidonic acid to prostaglandins.
- Chloramphenicol
Binds to cyclophilins (peptidyl proline cis - trans isomerase) - blocking the differentiation and activation of T cells mainly by inhibiting the production of IL-2 and its receptor.

42. What drug is used to treat Trematode/fluke (e.g. - Schistosomes - Paragonimus - Clonorchis) or Cysticercosis
Praziquantel
- Shifts the curve down - reduces Vmax
Indirect agonist - uptake inhibitor
Acute coronary syndrome; coronary stenting. Decreases the incidence or recurrence of thrombotic stroke.

43. What antimicrobial class is Aztreonam syngergestic with?
- Oxalic acid - Acidosis & nephrotoxicity
Giant Roundworm (Ascaris) - Hookworm (Necator/Ancylostoma) - Pinworm (Enterobius)
PT
Aminoglycosides

44. Mannitol - toxicity?
pulmonary edema - dehydration
sedation - sleep alterations
decrease AP duration - affects ischemic or depolarized Purkinje and ventricular system
Methylzanthine; desired effect is bronchodilation - may cause bronchodilation by inhibiting phosphodiesterase - enzyme involved in degrading cAMP (controversial).

45. Toxicities associated with Acyclovir?
1. Hydrocortisone 2. Predisone 3. Triamcinolone 4. Dexamethasone 5. Beclomethasone
Leukopenia - Neutropenia - Thrombocytopenia - Renal toxicity
Delirium - Tremor - Nephrotoxicity
SLUD (salivation - Lacrimation - urination - Defecation)as well as airway secretion - GI motility - acid secretions

46. Antimicrobial prophylaxis for PCP
TMP- SMZ (DOC) - aerosolized pentamidine
Aplastic anemia (dose independent) - Gray Baby Syndrome
Sulfamethoxazole (SMZ) - Sulfisoxazole - Triple sulfas - Sulfadiazine
Gram + and Anerobes

47. What is the mechanism of action of the glucocorticoids?
WEPT: Warfarin affects the Extrinsic pathway and prolongs the PT.
Decrease the production of leukotrienes and protaglandins by inhibiting phospholipase A2 and expression of COX-2.
1. Bleeding 2. Teratogenicity 3. Drug - drug interactions
anticholinesterase glaucoma

48. What are toxic side effects for Metronidazole?
It must be Phosphorylated by Viral Thymidine Kinase
- Hydralazine - Procainamide - INH - phenytoin
Cell membrane Ca2+ channels of cardiac sarcomere
Disulfiram - like reaction with EtOH - Headache

49. What type of gout is treated with Probenacid?
- DNA intercalator - Hodgkin's - myeloma - sarcoma - and solid tumors - Cardiotoxicity & alopecia
Decreased uptake or Increased transport out of cell
Chronic gout.
Mg = Must go to the bathroom.

50. Which diuretics increase urine Ca2+?
prevention of nodal arrhythmias (SVT)
Ca2+ (Loops Lose calcium)
Treatment of hypertension - especially with renal disease (lowers bp centrally - so flow is maintained to kidney).
loop diuretics - spironolactone