Test your basic knowledge |

USMLE Step 1 Pharmacology

Subjects : health-sciences, usmle-step-1

Instructions:

Answer 50 questions in 15 minutes.
If you are not ready to take this test, you can study here.
Match each statement with the correct term.
Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

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. Explain pH dependent urinary drug elimination?
- Alkalinize urine & dialysis
- Weak Acids>Alkinalize urine(CO3) to remove more - Weak bases>acidify urine to remove more
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.
No. Atropine is used to reduce urgency in mild cystitis. So it would aggravate the urinary retention.

2. What is the MOA for Acyclovir?
Inhibit viral DNA polymerase
In treatment of malignant hyperthermia - due to concomitant use of halothane and succinylcholine. Also in neuroleptic malignant syndrome - a toxicity of antipsychotic drugs.
- Quinidine - quinine
- Constant AMOUNT eliminated per unit time. - Etoh & ASA

3. List the specific antidote for this toxin: Benzodiazepines
Penicillin - Ampicillin - Ticarcillin - Pipercillin - Imipenem - Aztreonam - Cephalosporins
- Flumazenil
Benzathine penicillin G
Praziquantel

4. What are four clinical uses of glucocorticoids?

Warning: Invalid argument supplied for foreach() in /var/www/html/basicversity.com/show_quiz.php on line 183

5. What can result due to antacid overuse?
Can affect absorption - bioavailability - or urinary excretion of other drugs by altering gastric and urinary pH or by delaying gastric emptying.
sedation - sleep alterations
CMV - esp in Immunocompromised patients
Gemfibrozil - Clofibrate

6. What is the clinical utility of clonidine?
1. Cimetadine 2. Ranitidine 3. Famotidine 4. Nizatidine
Treatment of hypertension - especially with renal disease (lowers bp centrally - so flow is maintained to kidney).
Babiturate.
pulmonary edema - dehydration

7. MOA: Block cell wall synthesis by inhib. Peptidoglycan cross - linking (7)
- Corticosteroids - heparin
increase AP duration - increase ERP - increase QT interval - for use When other arrhythmics fail
Penicillin - Ampicillin - Ticarcillin - Pipercillin - Imipenem - Aztreonam - Cephalosporins
1) Aminoglycosides = bactericidal 2) Tetracyclines = bacteriostatic

8. Which Tetracycline is used in patients with renal failure? / Why?
Doxycycline - because it is fecally eliminated
Acetylcholine esterase
Pyridoxine (B6) administration
dizziness - flushing - constipation (verapamil) - nausea

9. Antiarrhythmic class IV- clinical use?
prevention of nodal arrhythmias (SVT)
hyperkalemia - endocrine effects (gynecomastia - anti - androgen)
HTN - CHF - calcium stone formation - nephrogenic DI.
Tricyclic antidepressant.

10. What is the memory key to remember Which pathway (extrinsic vs. intrinsic) and Which lab value Warfarin affects?
WEPT: Warfarin affects the Extrinsic pathway and prolongs the PT.
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
Treatment of hypertension - especially with renal disease (lowers bp centrally - so flow is maintained to kidney).
- Penicillin

11. K+ sparing diuretics - toxicity?
hyperkalemia - endocrine effects (gynecomastia - anti - androgen)
Acetylates and irreversibly inhibits cyclooxygenase (COX I and COX II) to prevent the conversion of arachidonic acid to prostaglandins.
Ganciclovir is more toxic to host enzymes
WEPT: Warfarin affects the Extrinsic pathway and prolongs the PT.

12. Adenosine - clinical use?
DOC in diagnosing and abolishing AV nodal arrhythmias
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.
In 4 half - lifes= (94%) T1/2 = (0.7x Vd)/CL
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.

13. What is the category - mechanism of action - and particular use of beclomethasone and prednisone in Asthma treatment?
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.)
Penicillin - Cephalosporins - Vancomycin - Aminoglycosides - Fluoroquinolones - Metronidazole
Hydralazine and Minoxidil
- Barbiturates - phenytoin - carbamazipine - rifampin - griseofulvin - quinidine

14. What are the nondepolarizing neuromuscular blocking drugs?
- Bleomycin - amiodarone - busulfan
Pretreat with antihistamines and a slow infusion rate
Tubocurarine - atracurium - mivacurium - pancuronium - vecuronium - rapacuronium
Misoprostol is contraindicated in women of childbearing potential because it is an abortifacient.

15. What are the clinical indications for bethanechol?
Activates cholinergic receptors on bladder and bowel smooth muscle - alleviating post - op and neurogenic ileus and urinary retention.
H2 antagonist
RESPIre
1) Serious Gram - infections resistant to other Beta lactams 2) Meningitis (most penetrate the BBB)

16. Which diuretics increase urine K+?
thiazides - amiloride
Blocking muscarinic receptors in the circular fibers of the eye - results in unopposed action of radial muscles to dilate.
all except the K+ sparing diuretics Spironolactone - Triamterene - Amiloride
Recurrent UTIs - Shigella - Salmonella - Pneumocystis carinii pneumonia

17. Your patient wants an effective drug to treat his motion sickness - What would you prescribe
Pentavalent Antimony
Impairs the synthesis of vitamin K- dependent clotting factors
Scopolamine
AZT

18. What is Niclosamide used for?
- Alkalinize urine & dialysis
troponin - tropomyosin system
Cestode/tapeworm (e.g. - D. latum - Taenia species Except Cysticercosis
Nifedipine - Verapamil - Diltiazem

19. For Warfarin What is the Treatment for overdose
Hypokalemic metabolic alkalosis - hyponatremia - hyperGlycemia - hyperLipidemia - hyperUricemia - hyperCalcemia - sulfa allergy.
IV vitamin K and fresh frozen plasma
Pentamidine
Antileukotriene; blocks leukotriene receptors.

20. What is the MOA of Ganciclovir?
Oral treatment of superficial infections
Keratin containing tissues - e.g. - nails
Give an antichloinesterase - neostigmine - edrophonium - etc
Inhibits CMV DNA polymerase

21. What are five disadvantages of Oral Contraceptives (synthetic progestins - estrogen)?
It affects beta receptors equally and is used in AV heart block (rare).
In 4 half - lifes= (94%) T1/2 = (0.7x Vd)/CL
1. Taken daily 2. No protection against STDs 3. Raises triglycerides 4. Depression - weight gain - nausea - HTN 5. Hypercoagulable state
acts at the proximal convoluted tubule to inhibit carbonic anhydrase. Causes self - limited sodium bicarb diuresis and reduction of total body bicarb stores.

22. Sotalol - toxicity?
Inhibits reabsorption of uric acid.
- Tetracycline
torsade de pointes - excessive Beta block
Cyclooxygenases (COX I - COX II).

23. What beta 2 agonist will help your 21yo Astma pt?
Extended spectrum penicillin: certain Gram + bacteria and Gram - rods
Albuterol - tertbutaline
Chagas' disease - American Trypanosomiasis (Trypanosoma cruzi)
Potent immunosuppressive used in organ transplant recipients.

24. What is the MOA for Rifampin?
prevention of nodal arrhythmias (SVT)
Gram + cocci - Gram - rods - and Anerobes
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.
Inhibits DNA dependent RNA polymerase

25. Is resistant to penicillinase?
- Alkalates DNA - CML - Pulmonary fibrosis hyperpigmentation
Severe Gram - rod infections.
competitive inhibirot of aldosterone in the cortical collecting tubule
Imipenem

26. Which drug(s) cause this reaction: Agranulocytosis (3)?
Treatment of infertility.
- Cloazapine - carbamazapine - colchicine - PTU
fetal renal toxicity - hyperkalemia
Inhibit RT of HIV and prevent the incorporation of viral genome into the host DNA

27. Which drug(s) cause this reaction: Aplastic anemia (5)?
Inhibits cGMP phosphodiesterase - casuing increased cGMP - smooth muscle relaxation in the corpus cavernosum - increased blood flow - and penile erection.
AZT
- Chloramphenicol - benzene - NSAIDS - PTU - phenytoin
Acetylcholinesterase; ACh is broken down into choline and acetate.

28. Which drug increases Sys BP w/o affecting Pulse Pressure
1. Gastric ulceration 2. Bleeding 3. Hyperventilation 4. Reye's syndrome 5. Tinnitus (CN VIII)
Epinephrine
Treatment of hypertension - especially with renal disease (lowers bp centrally - so flow is maintained to kidney).
Ipratropium

29. What is the clinical use of Tacrolimus (FK506)?
Altered bacterial Dihydropteroate Synthetase - Decreased uptake - or Increased PABA synthesis
cyanide toxicity (releases CN)
Potent immunosuppressive used in organ transplant recipients.
Hypersensitivity reactions

30. Acetazolamide causes?

Warning: Invalid argument supplied for foreach() in /var/www/html/basicversity.com/show_quiz.php on line 183

31. List the specific antidote for this toxin: Cyanide
- Nitrate - hydroxocobalamin thiosulfate
Non - Nucleosides
increase AP duration - increase ERP - increase QT interval - for use When other arrhythmics fail
impotence - asthma - CV effects (bradycardia - CHF - AV block) - CNS effects (sedation - sleep alterations)

32. What would be the effect on blood pressure with infusion of the alpha -2 agonist clonidine?
Digitoxin 168hrs Digoxin 40 hrs
GI discomfort - Acute cholestatic hepatitis - Eosinophilia - Skin rashes
Initially vasoconstriction would increase bp - but then it acts on central alpha -2 receptors to decrease adrenergic outflow resulting in decreased bp.
- Physostigmine salicylate

33. Which diuretics cause acidosis?
Neutropenia (ticlopidine); reserved for those who cannot tolerate aspirin.
Giardiasis - Amoebic dysentery (E. histolytica) - Bacterial vaginitis (Gardnerella vaginalis) - Trichomonas
carbonic anhydrase inhibitors - K+ sparing diuretics
Erythromycin - Azithromycin - Clarithromycin

34. What is the MOA for Methicillin - Nafcillin - and Dicloxacillin?
Ld= (CpxVd)/F Cp=plasma conc. F= Bioaval.
Gram + cocci - Gram - rods - and Anerobes
Same as penicillin. Act as narrow spectrum antibiotics
osmotic diuretic - increase tubular fluid osmolarity - thereby increasing urine flow

35. Which drug(s) cause this reaction: Cutaneous flushing (4)?
Phase 1 = prolonged depolarization - no antidote - effect potentiated by anticholinesterase; Phase 2 = repolarized but blocked - an anticholinesterase is the antidote for this phase.
They inhibit reuptake of NE at the nerve terminal (as does cocaine).
Hemicholinium inhibits the transport of choline into the nerve - thus inhibiting formation of ACh.
- Niacin - Ca++ channel blockers - adenosine - vancomycin

36. In coma situations you rule out What (7)?

Warning: Invalid argument supplied for foreach() in /var/www/html/basicversity.com/show_quiz.php on line 183

37. Cautions When using Amiodarone?
1. Significant: nephrotoxicity 2. Peripheral neuropathy 3. Hypertension 4. Pleural effusion 5. Hyperglycemia.
Antimetabolite derivative of 6- mercaptopurine that interferes with the metablolism and synthesis of nucleic acid.
Used in combination therapy with SMZ to sequentially block folate synthesis
check PFTs - LFTs - and TFTs

38. What is the category of drug names ending in - pril (e.g. Captopril)
Binds to the Pyrophosphate Binding Site of the enzyme
Nitrates
Bismuth and Amoxicillin or Tetracycline; against Helobacter pylori
ACE inhibitor.

39. What drug is given for Pneumocystis carinii prophylaxis?
Pentamidine
Acetylcholinesterase; ACh is broken down into choline and acetate.
check PFTs - LFTs - and TFTs
Increases mean - systolic - and diastolic bp - while there is little change in pulse pressure.

40. ACE inhibitors - clinical use?
Acetaminophen has antipyretic and analgesic properties - but lacks anti - inflammatory properties.
Initially vasoconstriction would increase bp - but then it acts on central alpha -2 receptors to decrease adrenergic outflow resulting in decreased bp.
YES
hypertension - CHF - diabetic renal disease

41. Mg+- clinical use?
effective in torsade de pointes and digoxin toxicity
Beta - lactam antibiotics
physostigmine
cardiac depression - peripheral edema - flushing - dizziness - constipation

42. What is the category and mechanism of action of Zafirlukast in Asthma treatment?
Beta lactams - inhibit cell wall synthesis - Bactericidal
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.
- EDTA - dimercaprol - succimer - & penicillamine
Antileukotriene; blocks leukotriene receptors.

43. List the specific antidote for this toxin: Methemoglobin
1. Renal damage 2. Aplastic anemia 3. GI distress
- Methylene blue
They activate the ciliary muscle of the eye (open angle) and pupillary sphincter (narrow angle).
Beta - lactam antibiotics

44. What are the side effects of Polymyxins?
Neurotoxicity - Acute renal tubular necrosis
No - it inhibits the release of Nor Epi
Penicillin.
Succinylcholine

45. What is the category of drug names ending in - operidol (e.g. Haloperidol)
Butyrophenone (neuroleptic).
Inhibt Assembly of new virus by Blocking Protease Enzyme
Ceftriaxone
Blocks translocation - binds to the 23S rRNA of the 50S subunit - Bacteriostatic

46. Furosemide - class and mechanism?
Norepinephrine (Alpha1 -2 and beta 1)
Depolymerizes microtubules - impairing leukocyte chemotaxis and degranulation.
Sulfonamide Loop Diuretic. Inhibits ion co - transport system of thick ascending loop. Abolishes hypertonicity of the medulla - thereby preventing concentration of the urine.
- reduction - oxy - & hydrolysis - H2O sol. Polar product - P450

47. What are two clinical uses of Azathioprine?
Because they require some residual islet function.
1. Kidney transplantation 2. Autoimmune disorders (including glomerulonephritis and hemolytic anemia)
Buy AT 30 - CELL at 50'
- Formaldehyde & formic acid - severe acidosis & retinal damage

48. What is the category - desired effect - and period of use of albuterol in the treatment of Asthma?
Beta 2 agonist; desired effect is the relaxation of bronchial smooth muscle (Beta 2). Use during acute exacerbation.
Fever/Chills - Hypotension - Nephrotoxicity - Arrhythmias
Terminal D- ala of cell wall replaced with D- lac; Decreased affinity
Dry flushed skin - due to inhibition of sympathetic post - ganglionic blockade on muscarinic receptors of sweat glands. All others are opposite of What would be expected.

49. What type of gout is treated with Probenacid?
Chronic gout.
- reduction - oxy - & hydrolysis - H2O sol. Polar product - P450
Inhibits IMP Dehydrogenase (competitively) - and therefore blocks Guanine Nucleotide synthesis
When pts have Low CD4+ (< 500 cells/cubic mm) or a High Viral Load

50. Which drug(s) cause this reaction: Tardive dyskinesia?
Giant Roundworm (Ascaris) - Hookworm (Necator/Ancylostoma) - Pinworm (Enterobius)
- Antipsychotics
It must be Phosphorylated by Viral Thymidine Kinase
- Isoniazid