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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. Which cancer drugs work at the level of proteins(2)?
- Vinca alkaloids(inhibit MT) - Paclitaxel
Yes
Blocking muscarinic receptors in the circular fibers of the eye - results in unopposed action of radial muscles to dilate.
- Estrogen receptor antagonist - Breast CA - increased endometrial CA risk

2. List the mechanism - clinical use - & toxicity of Busulfan.
- Alkalates DNA - CML - Pulmonary fibrosis hyperpigmentation
Anaerobic infections (e.g. - B. fragilis - C. perfringens)
Slow - limited by half lives of clotting factors
- Topo II inhibitor(GII specific) - Oat cell of Lung & prostate - & testicular - Myelosuppression & GI irritation.

3. What is the category - desired effect - and adverse effect of Isoproterenol in the treatment of Asthma?
Reversible block of histamine H2 receptors
hypertension - CHF - diabetic renal disease
Epinephirine(Alpha1 -2 and Beta 1 -2)
Nonspecific beta - agonist; desired effect is the relaxation of bronchial smooth muscle (Beta 2). Adverse effect is tachycardia (Beta 1).

4. What is the mechanism of action of Omeprazole - Lansoprazole?
Irreversibly inhibits H+/K+ ATPase in stomach parietal cells.
Dobutamine has more of an affintiy for beta -1 than beta -2 - and is used for treating heart failure and shock. Albuterol and terbutaline is the reverse - and is used in treatment of acute asthma.
- MT polymerization inhibitor(M phase) - MOPP - lymphoma - Willm's & choriocarcinoma - neurotoxicity and myelosuppression
Nephrotoxicity

5. What is are two clinical uses of Cyclosporine?
decrease AP duration - affects ischemic or depolarized Purkinje and ventricular system
- Fluoroquinolones
Rash - Pseudomembranous colitis
1. Suppresses organ rejection after transplantation 2. Selected autoimmune disorders.

6. What are toxic side effects for Metronidazole?
Disulfiram - like reaction with EtOH - Headache
INH: Injures Neurons and Hepatocytes
dry mouth - sedation - severe rebound hypertension
Acts as a wide spectrum carbapenem

7. What antimuscarinic drug is useful for the tx of asthma
Ipratropium
Gram + cocci - Proteus mirabilis - E. coli - Klebsiella pneumoniae (PEcK)
- Ethanol - dialysis - & fomepizole
increase AP duration - increase ERP - increase QT interval - for use When other arrhythmics fail

8. How does NE modulate its own release? What other neurotransmitter has this same effect?
NE acts presynaptically on alpha -2 receptors to inhibit its own release. ACh also acts presynaptically through M1 receptors to inhibit NE release.
Oxygen
They inhibit reuptake of NE at the nerve terminal (as does cocaine).
1. Cimetadine 2. Ranitidine 3. Famotidine 4. Nizatidine

9. What conditions are treated with Metronidazole?
Indirect agonist - uptake inhibitor
Giardiasis - Amoebic dysentery (E. histolytica) - Bacterial vaginitis (Gardnerella vaginalis) - Trichomonas
- ED 50 is less than the Km (less than 50% of receptors)
It must be Phosphorylated by Viral Thymidine Kinase

10. Which of epi - norepi - or isoproterenol results in bradycardia?
Norepinephrine
Increase target cell response to insulin.
increase AP duration - increase ERP - increase QT interval - for use When other arrhythmics fail
Butyrophenone (neuroleptic).

11. What is the mechanism of action of the glucocorticoids?
- Deferoxamine
Gemfibrozil - Clofibrate
Acetylates and irreversibly inhibits cyclooxygenase (COX I and COX II) to prevent the conversion of arachidonic acid to prostaglandins.
Decrease the production of leukotrienes and protaglandins by inhibiting phospholipase A2 and expression of COX-2.

12. What is an occasional side effect of Aztreonam?
Amphotericin B - Nystatin - Fluconazole/azoles
GI upset
Sucralfate cannot work in the presence of antacids or H2 blockers because it requires an acidic environment to polymerize.
Beta - lactamase cleavage of Beta - lactam ring

13. What is the category of drug names ending in - navir (e.g. Saquinavir)
Long.
Beta - lactam antibiotics
Protease inhibitor.
Gram + cocci - Proteus mirabilis - E. coli - Klebsiella pneumoniae (PEcK)

14. Name four HMG- CoA reductase inhibitors.
Lovastatin - Pravastatin - Simvastatin - Atorvastatin
1. Significant: nephrotoxicity 2. Peripheral neuropathy 3. Hypertension 4. Pleural effusion 5. Hyperglycemia.
fetal renal damage - hyperkalemia - Cough - Angioedema - Proteinuria - Taste changes - hypOtension - Pregnancy problems - Rash - Increased renin - Lower Angiotensin II (CAPTOPRIL)
Systemic mycoses

15. What are the Anti - TB drugs?
Prophylaxis for Influenza A - Rubella; Parkinson's disease
Gram + cocci - Gram - rods - and Anerobes
1. Aluminum hydroxide: constipation and hypophosphatemia 2. Magnesium hydroxide: diarrhea 3. Calcium carbonate: Hypercalcemia - rebound acid increase - All may cause hypokalemia
Rifampin - Ethambutol - Streptomycin - Pyrazinamide - Isoniazid (INH)

16. Which diuretics cause alkalosis?
Suramin
- Hypersensitivity reactions - Hemolysis - Nephrotoxicity (tubulointerstitial nephritis) - Kernicterus in infants Displace other drugs from albumin (e.g. - warfarin)
Heparin catalyzes the activation of antithrombin III.
loop diuretics - thiazides

17. Which RT inhibitor causes Megaloblastic Anemia?
AZT
Ciprofloxacin - Norfloxacin - Ofloxacin - Grepafloxacin - Enoxacin - Nalidixic acid
Chagas' disease - American Trypanosomiasis (Trypanosoma cruzi)
Theoretically it could be used to block the cephalic phase of acid secretion (vagal stimulation).

18. What is the memory key for the action of Sildenafil (Viagra)?
Acute gout.
NE acts presynaptically on alpha -2 receptors to inhibit its own release. ACh also acts presynaptically through M1 receptors to inhibit NE release.
- Lithium
Sildenafil fills the penis

19. For Warfarin What is the Treatment for overdose
viral kinase
IV vitamin K and fresh frozen plasma
Quinolones
fetal renal damage - hyperkalemia - Cough - Angioedema - Proteinuria - Taste changes - hypOtension - Pregnancy problems - Rash - Increased renin - Lower Angiotensin II (CAPTOPRIL)

20. Specifically - How does Foscarnet inhibit viral DNA pol?
Binds to the Pyrophosphate Binding Site of the enzyme
Praziquantel
Succinylcholine
Minor hepatotoxicity - Drug interactions (activates P450)

21. What are Aminoglycosides used for clinically?
Beta - lactamase cleavage of Beta - lactam ring
Severe Gram - rod infections.
- Barbiturates - phenytoin - carbamazipine - rifampin - griseofulvin - quinidine
GI discomfort - Acute cholestatic hepatitis - Eosinophilia - Skin rashes

22. How can the toxic effects of TMP be ameliorated?
Gram + - Gram - - Norcardia - Chlamydia
Potent immunosuppressive used in organ transplant recipients.
dizziness - flushing - constipation (verapamil) - nausea
With supplemental Folic Acid

23. What drug is used to diagnose myasthenia gravis?
Wide spectrum of systemic mycoses: Cryptococcus - Blastomyces - Coccidioides - Aspergillus - Histoplasma - Candida - Mucor
- Atropine & pralidoxime
Prophylaxis for Influenza A - Rubella; Parkinson's disease
edrophonium (extremely short acting anticholinesterase)

24. What is the category of drug names ending in - azol (e.g. Ketoconazole)
Antifungal.
reversible SLE- like syndrome
- Alkalates DNA - CML - Pulmonary fibrosis hyperpigmentation
- reduction - oxy - & hydrolysis - H2O sol. Polar product - P450

25. How does botulinum toxin result in respiratory arrest?
Nephrotoxicity
Inhibits xanthine oxidase - decresing conversion of xanthine to uric acid.
Prevents the release of calcium from the sarcoplasmic reticulum of skeletal muscle.
Prevents the release of ACh - Which results in muscle paralysis.

26. What are three toxicities of Leuprolied?
1. Antiandrogen 2. Nausea 3. Vomiting
Beta antagonist.
compensatory tachycardia - fluid retention - lupus - like syndrome
Topical and Oral - for Oral Candidiasis (Thrush)

27. ________ ae not resistant to penicillinase - - but they are less susceptible than the other Beta lactams
Mebendazole/Thiabendazole - Pyrantel Pamoate
Chronic anticoagulation.
Alpha -1 antagonist
Cephalosporins

28. Ca2+ sensitizers'- site of action?
troponin - tropomyosin system
Blocks translocation - binds to the 23S rRNA of the 50S subunit - Bacteriostatic
Inhibit RT of HIV and prevent the incorporation of viral genome into the host DNA
decrease conduction velocity - increase ERP - increase PR interval

29. Which drug(s) cause this reaction: P450 inhibition(6)?
Inhibits cell wall mucopeptide formation - Bactericidal
- Cimetidine - ketoconazole - grapefruit juice - erythromycin - INH - sulfonamides
Decrease the production of leukotrienes and protaglandins by inhibiting phospholipase A2 and expression of COX-2.
Gentamicin - Neomycin - Amikacin - Tobramycin - Streptomycin

30. Beta Blockers - BP?
decrease
Tricyclic antidepressant.
Onchocerciasis ('river blindness'-- rIVER- mectin)
diuretics - sympathoplegics - vasodilators - ACE inhibitors - Angiotensin II receptor inhibitors

31. What are three complications of Warfarin usage?
1. Bleeding 2. Teratogenicity 3. Drug - drug interactions
Hemicholinium inhibits the transport of choline into the nerve - thus inhibiting formation of ACh.
Prevention of NSAID- induced peptic ulcers - maintains a PDA.
1. Peptic ulcer 2. Gastritis 3. Esophageal reflux 4. Zollinger - Ellison syndrome

32. Which drug(s) cause this reaction: Atropine - like side effects?
- Tricyclic antidepressants
Carbachol - pilocarpine - physostigmine - echothiophate
Aminoglycosides - Tetracyclines
Chronic (weeks or months)

33. What is the chemical name for Ganciclovir?
DHPG (dihydroxy-2- propoxymethyl guanine)
cholestyramine - colestipol
- Alkalates DNA - CML - Pulmonary fibrosis hyperpigmentation
Lovastatin - Pravastatin - Simvastatin - Atorvastatin

34. Name the common Non - Nucleoside Reverse Transcriptase Inhibitors
- Isoniazid
GI upset
Inhibits Viral DNA polymerase
Nevirapine - Delavirdine

35. As an Anes you want to use a depolarizing neuromuscular blocking drug on your pt - What do you use
In treatment of malignant hyperthermia - due to concomitant use of halothane and succinylcholine. Also in neuroleptic malignant syndrome - a toxicity of antipsychotic drugs.
Beta1 more than B2
Succinylcholine
K+ wasting - metabolic alkalosis - hypotension - ototoxicity

36. Which drug(s) cause this reaction: Gray baby syndrome?
1. Aluminum hydroxide: constipation and hypophosphatemia 2. Magnesium hydroxide: diarrhea 3. Calcium carbonate: Hypercalcemia - rebound acid increase - All may cause hypokalemia
increased AP duration - increased ERP increased QT interval. Atrial and ventricular.
Yes
- Chloramphenicol

37. These drugs acts indirectly by releasing strored catecholamines in the presynaptic terminal
compensatory tachycardia - fluid retention - lupus - like syndrome
Decreases synthesis of Mycolic Acid
Keratin containing tissues - e.g. - nails
Amphetamine and Ephedrine

38. How is Ganciclovir activated?
vascular sm. Mus.: Nifedipine>Diltiazem>Verapamil
Yes
Phosphorylation by a Viral Kinase
Sulfamethoxazole (SMZ) - Sulfisoxazole - Triple sulfas - Sulfadiazine

39. How does a competitive antagonist effect an agonist?
To inhibit renal Dihydropeptidase I and decrease Imipenem inactivation in the renal tubules
- Vinca alkaloids(inhibit MT) - Paclitaxel
Prevents the release of calcium from the sarcoplasmic reticulum of skeletal muscle.
- Shifts the curve to the right - increases Km

40. What two vasodilators require simultaneous treatment with beta blockers to prevent reflex tachycardia and diuretics to prevent salt retention?
GI upset - Superinfections - Skin rashes - Headache - Dizziness
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.
Hydralazine and Minoxidil
Diarrhea

41. How is Vancomycin used clinically?
Tendonitis and Tendon rupture
Staphlococcus aureus
For serious - Gram + multidrug - resistant organisms
Inhibits organification and coupling of thyroid hormone synthesis. Also decreases peripheral conversion of T4 to T3.

42. What are five possible toxic effects of Aspirin therapy?

43. Why would you use pralidoxime after exposure to an organophosphate?
blocking the beta adrenergic receptor leads to decreased cAMP - and decreased Ca2+ flux
NO
Binds ergosterol - Disrupts fungal membranes
Pralidoxime regenerates active cholinesterase.

44. What beta 2 agonist will help your 21yo Astma pt?
Meningitis (H. influenza - N. meningitidis - S. pneumoniae) - Conserative treatment due to toxicities
new arrhythmias - hypotension
Albuterol - tertbutaline
Blocks translocation - binds to the 23S rRNA of the 50S subunit - Bacteriostatic

45. A common side effects of Interferon (INF) treatment is?
edematous states (CHF - cirrhosis - nephrotic syndrome - pulm edema) - HTN - hypercalcemia
- Topo II inhibitor(GII specific) - Oat cell of Lung & prostate - & testicular - Myelosuppression & GI irritation.
Neutropenia
orthostatic and exercise hypotension - sexual dysfunction - diarrhea

46. Which drug(s) cause this reaction: Drug induced Parkinson's (4) ?
Ciprofloxacin - Norfloxacin - Ofloxacin - Grepafloxacin - Enoxacin - Nalidixic acid
Inhibits cell wall mucopeptide formation - Bactericidal
fetal renal damage - hyperkalemia - Cough - Angioedema - Proteinuria - Taste changes - hypOtension - Pregnancy problems - Rash - Increased renin - Lower Angiotensin II (CAPTOPRIL)
- Haloperidol - chlorpromazine - reserpine - MPTP

47. What are four H2 Blockers?
Inhibt Assembly of new virus by Blocking Protease Enzyme
- partial agonist can have increased - decreased - /A21or equal potency as full agonist. - Potency is an independent factor.
Atropine pts are suffering from Cholinestrase inhibitor poisining (Nerve gas/Organophosphate poisining)
1. Cimetadine 2. Ranitidine 3. Famotidine 4. Nizatidine

48. List the specific antidote for this toxin: TPA & Streptokinase
osmotic diuretic - increase tubular fluid osmolarity - thereby increasing urine flow
vasodilator - increases cGMP to induce smooth muscle relaxation (arterioles>veins; afterload reduction)
- N- acetylcystine
- Aminocaproic acid

49. What is the effect of TCA's on the adrenergic nerve?
decrease AP duration - affects ischemic or depolarized Purkinje and ventricular system
IV vitamin K and fresh frozen plasma
Gram + cocci - Proteus mirabilis - E. coli - Klebsiella pneumoniae (PEcK)
They inhibit reuptake of NE at the nerve terminal (as does cocaine).

50. A 12yo patient was treated for a reaction to a bee sting - What drug provides the best coverage of sympathomimetic receptors?
Praziquantel
- Alkalinize urine & dialysis
Epinephirine(Alpha1 -2 and Beta 1 -2)
Large anionic polymer - acidic