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. What is the clinical use for Warfarin?
Pseudomonas species and Gram - rods
Bethanechol - Neostigmine - physostigmine
Cephalosporin: 1) has a 6 member ring attached to the Beta lactam instead of a 5 member ring 2)has an extra functional group ( attached to the 6 member ring)
Chronic anticoagulation.

2. Steady state concentration is reached in __ number of half - lifes
Amphotericin B - Nystatin - Fluconazole/azoles
In 4 half - lifes= (94%) T1/2 = (0.7x Vd)/CL
Acute coronary syndrome; coronary stenting. Decreases the incidence or recurrence of thrombotic stroke.
No - warfarin - unlike heparin - can cross the placenta.

3. List the mechanism - clinical use - & toxicity of Methotrexate.
- Ammonium Chloride
Rifampin - Ethambutol - Streptomycin - Pyrazinamide - Isoniazid (INH)
- S- phase anti - metabolite folate analogue - Luk - Lymp - sarc - RA - & psoriasis / - Reversible myelosuppression
Foscarnet = pyroFosphate analog

4. What are the four conditions in Which Omeprazole - Lansoprazole is used?
Sildenafil fills the penis
1. Peptic ulcer 2. Gastritis 3. Esophageal reflux 4. Zollinger - Ellison syndrome
Protease inhibitor.
Acute (hours)

5. What is the category of drug names ending in - navir (e.g. Saquinavir)
Protease inhibitor.
1. Renal damage 2. Aplastic anemia 3. GI distress
- Sulfonamides - furosemide - methicillin - rifampin - NSAIDS (ex. ASA)
- ACE inhibitors (Losartan>no cough)

6. MOA: Block nucleotide synthesis
Ld= (CpxVd)/F Cp=plasma conc. F= Bioaval.
1. Better bioavailability 2. 2 to 4 times longer half life 3. Can be administered subcutaneously 4. Does not require laboratory monitoring
Sulfonamides - Trimethoprim
cyanide toxicity (releases CN)

7. List the mechanism - clinical use - & toxicity of Doxorubicin.

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

8. List the mechanism - clinical use - & toxicity of Paclitaxel.
Md= (CpxCL)/F Cp= plas. Conc. CL=clear. F=bioaval.
Blocks Peptide Bond formation at the 50S subunit - Bacteriostatic
cholestyramine - colestipol
- MT polymerization stabilizer - Ovarian & breast CA - Myelosupperession & hypersensitivity.

9. What is the category of drug names ending in - triptyline (e.g. Amitriptyline)
Tricyclic antidepressant.
loop diuretics - thiazides
Long.
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.

10. How does dantrolene work?
Pseudomembranous colitis (C. difficile) - fever - diarrhea
AluMINIMUM amount of feces.
Blood
Prevents the release of calcium from the sarcoplasmic reticulum of skeletal muscle.

11. What do you treat Nematode/roundworm (pinworm - whipworm) infections with?
Mebendazole/Thiabendazole - Pyrantel Pamoate
Systemic mycoses
Pituitary hormone.
blocking the beta adrenergic receptor leads to decreased cAMP - and decreased Ca2+ flux

12. For Heparin What is the Structure
Sulfonamides - Trimethoprim
It inhibits release of NE.
Large anionic polymer - acidic
penicillinase resistant

13. Why would a patient with cog - wheel rigidity and a shuffling gait be given benztropine?
Triple Therapy' 2 Nucleoside RT Inhibitors with a Protease Inhibitor
Parkinson patients benefit from antimuscarinic agents through its inhibitory action within the indirect pathway.
Non - Nucleosides
- Acetaldehyde - Nausea - vomiting - headache - & hypotension

14. Mannitol - site of action?
- ACE inhibitors (Losartan>no cough)
proximal convoluted tubule - thin descending limb - and collecting duct
Nonspecific beta - agonist; desired effect is the relaxation of bronchial smooth muscle (Beta 2). Adverse effect is tachycardia (Beta 1).
Cimetidine is a potent inhibitor of P450; it also has an antiandrogenic effect and decreases renal excretion of creatinine. Other H2 blockers are relatively free of these effects.

15. The COX-2 inhibitors (celecoxib - rofecoxib) have similar side effects to the NSAIDs with What one exception?
Inhibit viral DNA polymerase
The COX-2 inhibitors should not have the corrosive effects of other NSAIDs on the gastrointestinal lining.
- Alkalates DNA - CML - Pulmonary fibrosis hyperpigmentation
Cardiac glycoside (inotropic agent).

16. What Sulfonamides are used for simple UTIs?
Wide spectrum of systemic mycoses: Cryptococcus - Blastomyces - Coccidioides - Aspergillus - Histoplasma - Candida - Mucor
- Bleomycin - amiodarone - busulfan
- Alkalating agent - testicular - bladder - ovary -& lung - Nephrotoxicity & CN VIII damage.
Triple sulfas or SMZ

17. What are are the Sulfonylureas (general description) and What is their use?
Gram + cocci - Haemophilus influenza - Enterobacter aerogenes - Neisseria species - P. mirabilis - E. coli - K. pneumoniae - Serratia marcescens ( HEN PEcKS )
Sulfonylureas are oral hypoglycemic agents - they are used to stimulate release of endogenous insulin in NIDDM (type -2).
blocks SR Ca2+ channels
Terminal D- ala of cell wall replaced with D- lac; Decreased affinity

18. What is the category of drug names ending in - cillin (e.g. Methicillin)
PT
Mg = Must go to the bathroom.
Penicillin.
Local anesthetic.

19. For Warfarin What is the Duration of action
- Disulfram & also sulfonylureas - metronidazole
Chronic (weeks or months)
- Vitamin K & fresh frozen plasma
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 MOA for Rifampin?
Anaerobic infections (e.g. - B. fragilis - C. perfringens)
Inhibits DNA dependent RNA polymerase
glaucoma - urinary alkalinization - metabolic alkalosis - altitude sickness
Inhibits IMP Dehydrogenase (competitively) - and therefore blocks Guanine Nucleotide synthesis

21. How is Amphotericin B used clinically?
NE increases bp - Which stimulates baroreceptors in the carotid sinus and the aorta. The CNS signals through vagal stimulation to decrease heart rate.
Hydralazine and Minoxidil
Wide spectrum of systemic mycoses: Cryptococcus - Blastomyces - Coccidioides - Aspergillus - Histoplasma - Candida - Mucor
Impairs the synthesis of vitamin K- dependent clotting factors

22. Which drug(s) cause this reaction: Anaphylaxis?
Doxycycline - because it is fecally eliminated
NE increases bp - Which stimulates baroreceptors in the carotid sinus and the aorta. The CNS signals through vagal stimulation to decrease heart rate.
sedation - sleep alterations
- Penicillin

23. Antimicrobial prophylaxis for Syphilis
Edrophonium
- Halothane - Valproic acid - acetaminophen - Amantia phalloides
Benzathine penicillin G
Indirect agonist - uptake inhibitor

24. Acetazolamide causes?

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

25. Toxic side effects of the Azoles?
Chronic Hepatitis A and B - Kaposi's Sarcoma
Prophylaxis for Influenza A - Rubella; Parkinson's disease
Hormone synthesis inhibition (Gynecomastia) - Liver dysfunction (Inhibits CYP450) - Fever - Chills
1. Streptokinase 2. Urokinase 3. tPA (alteplase) - APSAC (anistreplase)

26. Ethacrynic Acid - toxicity?
Staphlococcus aureus and Clostridium difficile (pseudomembranous colitis)
NO HYPERURICEMIA - NO SULFA AllERGY; same as furosemide otherwise
GET on the Metro
Muscarinic antagonist; competatively blocks muscarinic receptors - preventing bronchoconstriction.

27. What is the mechanism of action of the Alpha - glucosidase inhibitors?
Mg = Must go to the bathroom.
increase AP duration - increase ERP - increase QT interval - for use When other arrhythmics fail
Rifampin - Ethambutol - Streptomycin - Pyrazinamide - Isoniazid (INH)
Inhibit intestinal bursh border Alpha - glucosidases; delayed hydrolysis of sugars and absorption of sugars leading to decresed postprandial hyperglycemia.

28. What is Nifurtimox administered for?

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

29. What is the MOA for Metronidazole?
Due to the presence of a bulkier R group
Forms toxic metabolites in the bacterial cell - Bactericidal
1. Hot flashes 2. Ovarian enlargement 3. Multiple simultaneous pregnancies 4. Visual disturbances
- EDTA - dimercaprol - succimer - & penicillamine

30. Hydrochlorothiazide - mechanism?
for RSV
Same as penicillin. Act as narrow spectrum antibiotics
GI upset - Superinfections - Skin rashes - Headache - Dizziness
Inhibits NaCl reabsorption in the early distal tubule. Decreases Ca2+ excretion.

31. What are two types of drugs that interfere with the action of Sucralfate and why?
Dopamine
Sucralfate cannot work in the presence of antacids or H2 blockers because it requires an acidic environment to polymerize.
effective in torsade de pointes and digoxin toxicity
Oral

32. What are the Macrolides used for clinically?
It affects beta receptors equally and is used in AV heart block (rare).
Edrophonium
- Upper respiratory tract infections - pneumonias - STDs: Gram+ cocci (streptococcal infect in pts allergic to penicillin) - Mycoplasma - Legionella - Chlamydia - Neisseria
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.

33. What sympathomimetic would you not prescribe for hypotension in a pt with renal artery sclerosis.
- Antipsychotics
Buy AT 30 - CELL at 50'
Norepinephrine (Alpha1 -2 and beta 1)
1) Chloramphenical = bacteriostatic 2) Erythromycin = bacteriostatic 3) Lincomycin = bacteriostatic 4)cLindamycin = bacteriostatic

34. Name the common Aminoglycosides (5)
- Physostigmine salicylate
Gentamicin - Neomycin - Amikacin - Tobramycin - Streptomycin
- Phenytoin
Methicillin - Nafcillin - and Dicloxacillin

35. Why is carbachol and pilocarpine useful in treatment of glaucoma?
Inhibits NaCl reabsorption in the early distal tubule. Decreases Ca2+ excretion.
They activate the ciliary muscle of the eye (open angle) and pupillary sphincter (narrow angle).
- Glucocorticoid withdrawal
Fast vs. Slow Acetylators

36. Which cancer drugs effect nuclear DNA (4)?
Neutropenia
- Alkalating agents+cisplatin - Doxorubicin+Dactinomycin - Bleomycin - Etoposide
Binds Ergosterol - forms Membrane Pores that Disrupt Homeostatis
Inhibits organification and coupling of thyroid hormone synthesis. Also decreases peripheral conversion of T4 to T3.

37. What are five advantages of Oral Contraceptives (synthetic progestins - estrogen)?
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
Amphetamine and Ephedrine
- Disulfram & also sulfonylureas - metronidazole
- Glucocorticoid withdrawal

38. Beta Blockers - CV toxicity?
It inhibits release of NE.
Inhibits NaCl reabsorption in the early distal tubule. Decreases Ca2+ excretion.
Prophylaxis for Influenza A - Rubella; Parkinson's disease
bradycardia - AV block - CHF

39. What is the mechanism of action of Clomiphene?
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.
- Class III antiarrhythmics (sotalol) - class IA (quinidine)
- Alkalates DNA - CML - Pulmonary fibrosis hyperpigmentation
Digitoxin 168hrs Digoxin 40 hrs

40. List the mechanism - clinical use - & toxicity of 6 MP.
Pretreat with antihistamines and a slow infusion rate
DOC in diagnosing and abolishing AV nodal arrhythmias
Anaerobic infections (e.g. - B. fragilis - C. perfringens)
- inhibits HGPRT (pur. Syn.) - Luk - Lymph

41. Triamterene and amiloride - mechanism?
- Isoniazid
- Constant AMOUNT eliminated per unit time. - Etoh & ASA
Atropine would also block the receptors in the ciliary muscle - causing an impairment in accommodation (cycloplegia).
block Na+ channels in the cortical collecting tubule

42. Which Tetracycline is used in patients with renal failure? / Why?
Antimetabolite derivative of 6- mercaptopurine that interferes with the metablolism and synthesis of nucleic acid.
fetal renal damage - hyperkalemia - Cough - Angioedema - Proteinuria - Taste changes - hypOtension - Pregnancy problems - Rash - Increased renin - Lower Angiotensin II (CAPTOPRIL)
Doxycycline - because it is fecally eliminated
PT

43. What is a common side effect of Misoprostol?
Useful in muscle paralysis during surgery or mechanical ventilation.
Diarrhea
Tubocurarine - atracurium - mivacurium - pancuronium - vecuronium - rapacuronium
Ibuprofen - Naproxen - and Indomethacin

44. What are the indications for using amphetamine?

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

45. What is the memory key for Isoniazid (INH) toxicity?
CMV - esp in Immunocompromised patients
- Nitrate - hydroxocobalamin thiosulfate
Theoretically it could be used to block the cephalic phase of acid secretion (vagal stimulation).
INH: Injures Neurons and Hepatocytes

46. What are two processes Corticosteroids inhibit leading to decreased inflammation?
CL= (rate of elimination of drug/ Plasma drug conc.)
dizziness - flushing - constipation (verapamil) - nausea
1. Phospholipase A2 is prevented from releasing arachidonic acid 2. Decreases protein synthesis thus lowering amount of Cyclooxygenase enzymes
NO HYPERURICEMIA - NO SULFA AllERGY; same as furosemide otherwise

47. Common toxicities associated with Griseofulvin?
alpha -1 > alpha -2; used as a pupil dilator - vasoconstrictor - and for nasal decongestion
Tricyclic antidepressant.
aPTT (intrinsic pathway)
Teratogenic - Carcinogenic - Confusion - Headaches

48. List the specific antidote for this toxin: Anticholinesterases (organophosphate.)
Binds to the Pyrophosphate Binding Site of the enzyme
- Atropine & pralidoxime
- Barbiturates - phenytoin - carbamazipine - rifampin - griseofulvin - quinidine
torsade de pointes

49. ___________ are Teratogenic
- EDTA - dimercaprol - succimer - & penicillamine
sedation - sleep alterations
Aminoglycosides
Acetylcholine esterase

50. Name the common Non - Nucleoside Reverse Transcriptase Inhibitors
troponin - tropomyosin system
Polymyxins
Nevirapine - Delavirdine
With supplemental Folic Acid