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 MOA for the Azoles?
- reduction - oxy - & hydrolysis - H2O sol. Polar product - P450
- ED 50 is less than the Km (less than 50% of receptors)
Inhibit Ergosterol synthesis
- Act on same receptor - Full has greater efficacy

2. Which Aminoglycoside is used for Bowel Surgery ?
Diarrhea
With an amino acid change of D- ala D- ala to D- ala D- lac
Doxycycline - because it is fecally eliminated
Neomycin

3. Name four Antiarrhythmic drugs in class IA.
NO HYPERURICEMIA - NO SULFA AllERGY; same as furosemide otherwise
Quinidine - Amiodarone - Procainamide - Disopyramide
Polymyxin B - Polymyxin E
Sulfonamides - Trimethoprim

4. For Heparin What is the Ability to inhibit coagulation in vitro
CMV Retinitis in IC pts When Ganciclovir fails
Only in limited amounts
Slow - limited by half lives of clotting factors
Yes

5. What is the mechanism of action of Allopurinol used to treat chronic gout?
1. Predisposes to viral infections and lymphoma 2. Nephrotoxic (preventable with mannitol diuresis)
Finasteride inhibits 5 Alpha - reductase - this decreases the conversion of testosterone to dihydrotestosterone - useful in BPH
Acute coronary syndrome; coronary stenting. Decreases the incidence or recurrence of thrombotic stroke.
Inhibits xanthine oxidase - decresing conversion of xanthine to uric acid.

6. Which diuretics increase urine K+?
Pretreat with antihistamines and a slow infusion rate
Methylxanthine.
all except the K+ sparing diuretics Spironolactone - Triamterene - Amiloride
Used in combination therapy with SMZ to sequentially block folate synthesis

7. What is the clinical use for Heparin?
Immediate anticoagulation for PE - stroke - angina - MI - DVT.
Finasteride inhibits 5 Alpha - reductase - this decreases the conversion of testosterone to dihydrotestosterone - useful in BPH
Antiprotozoal: Giardia - Entamoeba - Trichomonas - Gardnerella vaginalis Anaerobes: Bacteroides - Clostridium
Captopril - Enalapril - Lisinopril

8. Which individuals are predisposed to Sulfonamide - induced hemolysis?
constipation - flushing - edema - CV effects (CHF - AV block - sinus node depression) - and torsade de pointes (Bepridil)
Beta - lactamase cleavage of Beta - lactam ring
hypertension - CHF - diabetic renal disease
G6PD deficient individuals

9. Guanethidine enhances the release of Norepi?
Aminoglycosides - Tetracyclines
- Oxalic acid - Acidosis & nephrotoxicity
No - it inhibits the release of Nor Epi
TCA

10. What are two Alpha - glucosidase inhibitors?
NO HYPERURICEMIA - NO SULFA AllERGY; same as furosemide otherwise
- Halothane - Valproic acid - acetaminophen - Amantia phalloides
thick ascending limb
1. Acarbose 2. Miglitol

11. Do Tetracyclines penetrate the CNS?
GET on the Metro
fetal renal damage - hyperkalemia - Cough - Angioedema - Proteinuria - Taste changes - hypOtension - Pregnancy problems - Rash - Increased renin - Lower Angiotensin II (CAPTOPRIL)
Only in limited amounts
Blocks Peptide Bond formation at the 50S subunit - Bacteriostatic

12. What is the difference between the affinity for beta receptors between albuterol/terbutaline and dantroline?
reversible SLE- like syndrome
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.
decrease
Similar to cyclosporine; binds to FK- binding protein - inhibiting secretion of IL-2 and other cytokines.

13. Ca2+ channel blockers - clinical use?
atropine - homatropine - tropicamide
hypertension - angina - arrhythmias
Increase target cell response to insulin.
all of them

14. Acetazolamide - clinical uses?
glaucoma - urinary alkalinization - metabolic alkalosis - altitude sickness
cyanide toxicity (releases CN)
- Sulfonamides - INH - ASA - Ibuprofen - primaquine - nitrofurantoin /- pyrimethamine - chloramphenicol
Chagas' disease - American Trypanosomiasis (Trypanosoma cruzi)

15. What are two Glitazones?
1. Pioglitazone 2. Rosiglitazone.
ARF - shock - drug overdose - decrease intracranial/intraocular pressure
Gram + and Anerobes
Babiturate.

16. What is the MOA for the Aminoglycosides?
Inhibits formation of Initiation Complex - causes misreading of mRNA - Bactericidal
Dermatophytes (tinea - ringworm)
Antileukotriene; blocks synthesis by lipoxygenase.
Sildenafil fills the penis

17. What is used to reverse the action of Heparin?
Fever/Chills - Hypotension - Nephrotoxicity - Arrhythmias
Protamine Sulfate is used for rapid reversal of heparinization (positively charged molecule that binds to negatively charged heparin).
fetal renal toxicity - hyperkalemia - Cough - Angioedema - Proteinuria - Taste changes - hypOtension - Pregnancy problems - Rash - Increased renin - Lower Angiotensin II (CAPTOPRIL)
Modification via Acetylation

18. What is a prerequisite for Acyclovir activation?
It must be Phosphorylated by Viral Thymidine Kinase
Decreases synthesis of Mycolic Acid
Epinephirine(Alpha1 -2 and Beta 1 -2)
Only in limited amounts

19. What is the MOA for Rifampin?
Diarrhea
hypertension - angina - arrhythmias
amphetamine and ephedrine
Inhibits DNA dependent RNA polymerase

20. Hydrochlorothiazide - clinical use?
Diuresis in pateints with sulfa allergy
HTN - CHF - calcium stone formation - nephrogenic DI.
hypertension - angina - arrhythmias
It must be Phosphorylated by Viral Thymidine Kinase

21. What is the chemical name for Ganciclovir?
DHPG (dihydroxy-2- propoxymethyl guanine)
No
- Vinca alkaloids(inhibit MT) - Paclitaxel
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)

22. Secretion of What drug is inhibited by Probenacid used to treat chronic gout?
Choline acetyltransferase
Penicillin.
Albuterol - tertbutaline
Benzathine penicillin G

23. What are three toxicities of Propylthiouracil?
- Shifts the curve down - reduces Vmax
severe orthostatic hypotension - blurred vision - constipation - sexual dysfunction
1. Skin rash 2. Agranulocytosis (rare) 3. Aplastic anemia
- Niacin - Ca++ channel blockers - adenosine - vancomycin

24. What is a common side effect of Colchicine used to treat acute gout - especially When given orally?
propanolol - esmolol - metoprolol - atenolol - timolol
Staphlococcus aureus
Verapamil - Diltiazem - Bepridil
GI side effects. (Indomethacin is less toxic - more commonly used.)

25. What are the clinical indications for bethanechol?
- Alkalating agents+cisplatin - Doxorubicin+Dactinomycin - Bleomycin - Etoposide
Cardiac glycoside (inotropic agent).
GI upset - Superinfections - Skin rashes - Headache - Dizziness
Activates cholinergic receptors on bladder and bowel smooth muscle - alleviating post - op and neurogenic ileus and urinary retention.

26. List the mechanism - clinical use - & toxicity of 5 FU.
Sulfonamide Loop Diuretic. Inhibits ion co - transport system of thick ascending loop. Abolishes hypertonicity of the medulla - thereby preventing concentration of the urine.
- Act on same receptor - Full has greater efficacy
- S- phase anti - metabolite Pyr analogue - Colon - solid tumors - & BCC/ - Irreversible myelosuppression
- Airway - Breathing - Circulation - Dextrose (thiamine & narcan) - ABCD

27. What is the effect of guanethidine on adrenergic NE release?
hypertension - CHF - diabetic renal disease
It inhibits release of NE.
1. Acarbose 2. Miglitol
Hypersensitivity reactions

28. What is the category of drug names ending in - azol (e.g. Ketoconazole)
Antifungal.
Inhibits organification and coupling of thyroid hormone synthesis. Also decreases peripheral conversion of T4 to T3.
Resistant Gram - infections
Pretreat with antihistamines and a slow infusion rate

29. Antiarrhythmic class IA effects?
increased AP duration - increased ERP increased QT interval. Atrial and ventricular.
GI intolerance (nausea - diarrhea) - Hyperglycemia - Lipid abnormalities - Thrombocytopenia (Indinavir)
INH: Injures Neurons and Hepatocytes
Prevents the release of Ca from SR of skeletal muscle

30. What is a possible toxicity of Ticlopidine - Clopidogrel usage?
Neutropenia (ticlopidine); reserved for those who cannot tolerate aspirin.
Mebendazole/Thiabendazole - Pyrantel Pamoate
Prevents the release of calcium from the sarcoplasmic reticulum of skeletal muscle.
AmOxicillin has greater Oral bioavailability

31. List the mechanism - clinical use - & toxicity of 6 MP.
Tetracycline - Doxycycline - Demeclocycline - Minocycline
Leukopenia - Neutropenia - Thrombocytopenia - Renal toxicity
Early myocardial infarction.
- inhibits HGPRT (pur. Syn.) - Luk - Lymph

32. Name two LPL stimulators.
Treatment of infertility.
Ciprofloxacin - Norfloxacin - Ofloxacin - Grepafloxacin - Enoxacin - Nalidixic acid
Gemfibrozil - Clofibrate
- B51Naloxone / naltrexone (Narcan)

33. What is the mechanism of action and clinical use of the antiandrogen Flutamide?
Flutamide is a nonsteroidal competitive inhibitor of androgens at the testosterone receptor - used in prostate carcinoma.
Blocks Norepi - but not Dopamine
Praziquantel
1. Addison's disease 2. Inflammation 3. Immune suppression 4. Asthma

34. For Heparin What is the Lab value to monitor
Modification via Acetylation - Adenylation - or Phosphorylation
Nucleosides
Amphotericin B - Nystatin - Fluconazole/azoles
aPTT (intrinsic pathway)

35. Ethacrynic Acid - clinical use?
- Glucagon
INH: Injures Neurons and Hepatocytes
Diuresis in pateints with sulfa allergy
not a sulfonamide - but action is the same as furosemide

36. Name the Protease Inhibitors (4)
Rash - Pseudomembranous colitis
Saquinavir - Ritonavir - Indinavir - Nelfinavir
1. Peptic ulcer 2. Gastritis 3. Esophageal reflux 4. Zollinger - Ellison syndrome
- Shifts the curve to the right - increases Km

37. What are two types of drugs that interfere with the action of Sucralfate and why?
Chronic gout.
Nitrates
Sucralfate cannot work in the presence of antacids or H2 blockers because it requires an acidic environment to polymerize.
Acute gout.

38. List the specific antidote for this toxin: Beta Blockers
local anesthetic. CNS stimulation or depression. CV depression.
- Glucagon
Mechanism unknown; possibly inhibits gluconeogenesis and increases glycolysis; effect is to decrease serum glucose levels
Depolymerizes microtubules - impairing leukocyte chemotaxis and degranulation.

39. What are the major toxic side effects of Imipenem/cilastatin?
compensatory tachycardia - fluid retention - lupus - like syndrome
It inhibits release of NE.
GI distress - Skin rash - and Seizures at high plasma levels
Dermatophytes (tinea - ringworm)

40. Antiarrhythmic Class III- effects?
Ataxia - Dizziness - Slurred speech
The COX-2 inhibitors should not have the corrosive effects of other NSAIDs on the gastrointestinal lining.
increase AP duration - increase ERP - increase QT interval - for use When other arrhythmics fail
Ganciclovir is more toxic to host enzymes

41. Beta Blockers - BP?
Oxygen
1. Peptic ulcer 2. Gastritis 3. Esophageal reflux 4. Zollinger - Ellison syndrome
decrease
Aluminum sucrose sulfate polymerizes in the acid environment of the stomach and selectively binds necrotic peptic ulcer tissue. Acts as a barrier to acid - pepsin - and bile.

42. ___________ are Teratogenic
Aminoglycosides
Aminoglycosides - Tetracyclines
NO
- Metronidazole - certain cephalosporins - procarbazine - sulfonylureas

43. What is combined with Ampicillin - Amoxicillin - Carbenicillin - Piperacillin - and Ticarcillin to enhance their spectrum?
Clavulanic acid
proximal convoluted tubule
physostigmine
Treatment of hypertension - especially with renal disease (lowers bp centrally - so flow is maintained to kidney).

44. Oral Penicillin
- Protamine
aPTT (intrinsic pathway)
Penicillin - V
1.Gram - rods of the Urinary and GI tracts (including Pseudomonas) 2.Neisseria 3. Some Gram + organisms

45. Why are albuterol and terbutaline effective in tx of acute asthmatic attacks?
Babiturate.
Finasteride inhibits 5 Alpha - reductase - this decreases the conversion of testosterone to dihydrotestosterone - useful in BPH
These B-2 agonists cause respiratory smooth muscle to relax.
Misoprostol is contraindicated in women of childbearing potential because it is an abortifacient.

46. The COX-2 inhibitors (celecoxib - rofecoxib) have similar side effects to the NSAIDs with What one exception?
The COX-2 inhibitors should not have the corrosive effects of other NSAIDs on the gastrointestinal lining.
GI discomfort
Verapamil - Diltiazem - Bepridil
Beta 2 agonist; used as a long - acting agent for prophylaxis. Adverse effects are tremor and arrhythmia.

47. What organism is Imipenem/cilastatin the Drug of Choice for?
Enterobacter
GI distress - Skin rash - and Seizures at high plasma levels
Rare.
Benzodiazepine.

48. MOA: Block peptidoglycan synthesis
bradycardia - AV block - CHF
Bacitracin - Vancomycin
Antibiotic - protein synthesis inhibitor.
- Steroids - Tamoxifen

49. What is the mechanism of action of Misoprostol?
With supplemental Folic Acid
Nitrates
Misoprostol is a PGE1 analog that increases the production and secretion of the gastic mucous barrier.
Phosphorylation by a Viral Kinase

50. Which antimicrobial classes inhibit protein synthesis at the 30S subunit? (2)
- Deferoxamine
1) Aminoglycosides = bactericidal 2) Tetracyclines = bacteriostatic
- Shifts the curve to the right - increases Km
- S- phase anti - metabolite folate analogue - Luk - Lymp - sarc - RA - & psoriasis / - Reversible myelosuppression