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. Ca2+ channel blockers - toxicity?
- Tricyclic antidepressants
cardiac depression - peripheral edema - flushing - dizziness - constipation
1. Peptic ulcer 2. Gastritis 3. Esophageal reflux 4. Zollinger - Ellison syndrome
Increased systolic and pulse pressure - decreased diastolic pressure - and little change in mean pressure.

2. Why are albuterol and terbutaline effective in tx of acute asthmatic attacks?
These B-2 agonists cause respiratory smooth muscle to relax.
- Chloramphenicol
Prevents the release of Ca from SR of skeletal muscle
aPTT (intrinsic pathway)

3. Decrease Digoxin dose in renal failure?
None. No - because atropine would block the postganglionic muscarinic receptors involved in sweat gland stimulation.
YES
Modification via Acetylation - Adenylation - or Phosphorylation
Protamine sulfate

4. Digoxin v. Digitoxin: protein binding?
Beta adrenergic receptors and Ca2+ channels (stimulatory)
Chronic Hepatitis A and B - Kaposi's Sarcoma
Digitoxin 70% Digoxin 20-40%
Acute coronary syndrome; coronary stenting. Decreases the incidence or recurrence of thrombotic stroke.

5. Adverse effects of Hydralazine?
nausea - headache - lupus - like syndrome - reflex tachycardia - angina - salt retention
Antileukotriene; blocks leukotriene receptors.
Liver
Inhibits bacterial Dihydrofolate Reductase - Bacteriostatic

6. What is the clinical use for Sildenafil (Viagra)?
Inhibits CMV DNA polymerase
- Aminocaproic acid
Intrathecally
Erectile dysfunction.

7. Norepi feedbacks and inhibits the presynaptic receptor by What mechanism
Binding to the presynaptic alpha 2 release modulating receptors
Gram + cocci - Proteus mirabilis - E. coli - Klebsiella pneumoniae (PEcK)
Parkinson patients benefit from antimuscarinic agents through its inhibitory action within the indirect pathway.
for RSV

8. What are Fluoroquinolones indicated for? (3)
1.Gram - rods of the Urinary and GI tracts (including Pseudomonas) 2.Neisseria 3. Some Gram + organisms
Beta antagonist.
Antibiotic - protein synthesis inhibitor.
Sulfamethoxazole (SMZ) - Sulfisoxazole - Triple sulfas - Sulfadiazine

9. How is Rifampin used clinically?
Beta adrenergic receptors and Ca2+ channels (stimulatory)
- Oral Contraceptives
1. Mycobacterium tuberculosis 2. Delays resistance to Dapsone When used of Leprosy 3. Used in combination with other drugs
acts at the proximal convoluted tubule to inhibit carbonic anhydrase. Causes self - limited sodium bicarb diuresis and reduction of total body bicarb stores.

10. What is the memory key involving the '4 R's of Rifampin?'
Antifungal.
Aminoglycosides - Tetracyclines
1. RNA pol inhibitor 2. Revs up P450 3. Red/orange body fluids 4. Rapid resistance if used alone
1. Streptokinase 2. Urokinase 3. tPA (alteplase) - APSAC (anistreplase)

11. What are two toxicities associated with Cyclosporine?
GI upset
decrease
Clavulanic acid
1. Predisposes to viral infections and lymphoma 2. Nephrotoxic (preventable with mannitol diuresis)

12. How is Ganciclovir used clinically?
Bind cell membrane - disrupt osmotic properties - Are Cationc - Basic and act as detergents
CMV - esp in Immunocompromised patients
Neutropenia (ticlopidine); reserved for those who cannot tolerate aspirin.
It affects beta receptors equally and is used in AV heart block (rare).

13. Which antimicrobials inhibit protein synthesis at the 50S subunit? (4)
Receptors = D1=D2>beta>alpha - thus increasing heart rate (beta) and blood pressure (alpha vasoconstriction) while maintaining kidney perfusion (dopamine receptors)
1) Chloramphenical = bacteriostatic 2) Erythromycin = bacteriostatic 3) Lincomycin = bacteriostatic 4)cLindamycin = bacteriostatic
Close K+ channels in Beta - cell membrane leading to cell depolarization causing insulin release triggered by increase in Calcium ion influx.
These B-2 agonists cause respiratory smooth muscle to relax.

14. What are five advantages of Oral Contraceptives (synthetic progestins - estrogen)?
acts at the proximal convoluted tubule to inhibit carbonic anhydrase. Causes self - limited sodium bicarb diuresis and reduction of total body bicarb stores.
Phenothiazine (neuroleptic - antiemetic).
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
GI upset - Superinfections - Skin rashes - Headache - Dizziness

15. What additional side effects exist for Ampicillin?
- Acetaldehyde - Nausea - vomiting - headache - & hypotension
- Topo II inhibitor(GII specific) - Oat cell of Lung & prostate - & testicular - Myelosuppression & GI irritation.
- Disulfram & also sulfonylureas - metronidazole
Rash - Pseudomembranous colitis

16. What is the category of drug names ending in - phylline (e.g. Theophylline)
Depolymerizes microtubules - impairing leukocyte chemotaxis and degranulation.
GI distress - Skin rash - and Seizures at high plasma levels
decrease the slope of phase 4 - increase PR interval (the AV node is particularly sensitive)
Methylxanthine.

17. Resistance mechanisms for Macrolides

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

18. What type of gout is treated with Allopurinol?
- Halothane - Valproic acid - acetaminophen - Amantia phalloides
1. Aluminum hydroxide: constipation and hypophosphatemia 2. Magnesium hydroxide: diarrhea 3. Calcium carbonate: Hypercalcemia - rebound acid increase - All may cause hypokalemia
GI side effects. (Indomethacin is less toxic - more commonly used.)
Chronic gout.

19. Which Aminoglycoside is used for Bowel Surgery ?
Lipoxygenase
1) Hypersensitivity reactions 2) Increased nephrotoxicity of Aminoglycosides 3) Disulfiram - like reaction with ethanol (those with a methylthiotetrazole group - e.g. - cefamandole)
- Act on same receptor - Full has greater efficacy
Neomycin

20. Antiarrhythmic class II- mechanism?
blocking the beta adrenergic receptor leads to decreased cAMP - and decreased Ca2+ flux
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
Penicillin - Ampicillin - Ticarcillin - Pipercillin - Imipenem - Aztreonam - Cephalosporins
Inhibits cell wall synthesis ( binds to PBP3). A monobactam

21. How does NE modulate its own release? What other neurotransmitter has this same effect?
Extended spectrum penicillin: certain Gram + bacteria and Gram - rods
Pregnant women - Children; because animal studies show Damage to Cartilage
Chloramphenicol - Erythromycin/macrolides - Lincomycin - Clindamycin - Streptogramins (quinupristin - dalfopristin)
NE acts presynaptically on alpha -2 receptors to inhibit its own release. ACh also acts presynaptically through M1 receptors to inhibit NE release.

22. Antiarrhythmic class II- toxicity?
- Phase I (clinical tests) - Phase II - Phase III - PhaseIV (surveillance)
Parkinson patients benefit from antimuscarinic agents through its inhibitory action within the indirect pathway.
impotence - exacerbation of asthma - CV effects - CNS effects - may mask hypoclycemia
TMP- SMZ (DOC) - aerosolized pentamidine

23. What is a common side effect of Colchicine used to treat acute gout - especially When given orally?
TCA
Protease inhibitor.
GI side effects. (Indomethacin is less toxic - more commonly used.)
Diarrhea

24. What is the category of drug names ending in - olol (e.g. Propranolol)
- Sulfonamides - furosemide - methicillin - rifampin - NSAIDS (ex. ASA)
Methylxanthine.
Beta antagonist.
Phase 1 = prolonged depolarization - no antidote - effect potentiated by anticholinesterase; Phase 2 = repolarized but blocked - an anticholinesterase is the antidote for this phase.

25. What beta 2 agonist will help your 21yo Astma pt?
Albuterol - tertbutaline
block Na+ channels in the cortical collecting tubule
- polymyxins
Mechanism unknown; possibly inhibits gluconeogenesis and increases glycolysis; effect is to decrease serum glucose levels

26. What enzymes are inhibited by NSAIDs - acetaminophen and COX II inhibitors?
1. Heavy bleeding 2. GI effects (n/v - anorexia) 3. Abdominal pain
Gemfibrozil - Clofibrate
1. Peptic ulcer 2. Gastritis 3. Esophageal reflux 4. Zollinger - Ellison syndrome
Cyclooxygenases (COX I - COX II).

27. What antimuscarinic agent is used in asthma and COPD?
Prevents the release of Ca from SR of skeletal muscle
Chagas' disease - American Trypanosomiasis (Trypanosoma cruzi)
Ipratropium
1. Infertility (pulsatile) 2. Prostate cancer (continuous: use with flutamide) 3. Uterine fibroids

28. Antiarrhythmic class II- effects?
decrease the slope of phase 4 - increase PR interval (the AV node is particularly sensitive)
- Shifts the curve to the right - increases Km
Atropine would also block the receptors in the ciliary muscle - causing an impairment in accommodation (cycloplegia).
Inhibits xanthine oxidase - decresing conversion of xanthine to uric acid.

29. What is the mechanism of action of Heparin?
Potent immunosuppressive used in organ transplant recipients.
cross - allergenic
Spironolactone - Triamterene - Amiloride (the K+ STAys)
Heparin catalyzes the activation of antithrombin III.

30. Which drug(s) cause this reaction: Hepatitis?
Small lipid - soluble molecule
not a sulfonamide - but action is the same as furosemide
- Isoniazid
Only in limited amounts

31. What is the mechanism of action of the Alpha - glucosidase inhibitors?
The PTT.
As PABA antimetabolites that inhibit Dihydropteroate Synthase - Bacteriostatic
Inhibit intestinal bursh border Alpha - glucosidases; delayed hydrolysis of sugars and absorption of sugars leading to decresed postprandial hyperglycemia.
physostigmine

32. What are Methicillin - Nafcillin - and Dicloxacillin used for clinically?
acts at the proximal convoluted tubule to inhibit carbonic anhydrase. Causes self - limited sodium bicarb diuresis and reduction of total body bicarb stores.
dizziness - flushing - constipation (verapamil) - nausea
Staphlococcus aureus
is resistant

33. What effect would atropine have on the preganglionic sympathetic activation of sweat glands? Would this person sweat?
None. No - because atropine would block the postganglionic muscarinic receptors involved in sweat gland stimulation.
Tricyclic antidepressant.
Disulfiram - like reaction with EtOH - Headache
GI discomfort

34. What are two conditions in Which COX-2 inhibitors might be used?
Same as penicillin. Extended spectrum antibiotics
Polymyxin B - Polymyxin E
- Oxalic acid - Acidosis & nephrotoxicity
Rheumatoid and osteoarthritis.

35. Does Warfarin have a long - medium - or short half life?
Long.
fetal renal toxicity - hyperkalemia
Albuterol - tertbutaline
Large anionic polymer - acidic

36. MOA: Block protein synthesis at 50s subunit
Decreased uptake or Increased transport out of cell
Chloramphenicol - Erythromycin/macrolides - Lincomycin - Clindamycin - Streptogramins (quinupristin - dalfopristin)
1. Cimetadine 2. Ranitidine 3. Famotidine 4. Nizatidine
Activates antithrombin III

37. What is the category of drug names ending in - caine (e.g. Lidocaine)
- MT polymerization inhibitor(M phase) - MOPP - lymphoma - Willm's & choriocarcinoma - neurotoxicity and myelosuppression
Local anesthetic.
- Oral Contraceptives
Chronic (weeks or months)

38. List the specific antidote for this toxin: Carbon monoxide
-100% oxygen - hyperbaric
Mycobacterium tuberculosis - the only agent used as solo prophylaxis against TB
No
Inhibit viral DNA polymerase

39. What is the specific clinical use of Indomethacin in neonates?
Indomethacin is used to close a patent ductus arteriosus.
Staphlococcus aureus and Clostridium difficile (pseudomembranous colitis)
- Fluoroquinolones
Gram + cocci - Gram - rods - and Anerobes

40. How would you reverse the effect of a neuromuscular blocking agent?
Hexamethonium is a nicotinic antagonist - and thus is a ganglionic blocker.
effective in torsade de pointes and digoxin toxicity
Give an antichloinesterase - neostigmine - edrophonium - etc
Na/K ATPase

41. What enzyme does Zileuton inhibit?
Blocks Norepi - but not Dopamine
Lipoxygenase
- Physostigmine salicylate
Primaquine

42. How can Vancomycin - induced 'Red Man Syndrome' be prevented?
Pretreat with antihistamines and a slow infusion rate
- Phenytoin
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.
Aplastic anemia (dose independent) - Gray Baby Syndrome

43. Ca2+ channel blockers - mechanism?
block voltage dependent L- type Ca2+ channels of cardiac and smooth muscle - decreasing contractility
- reduction - oxy - & hydrolysis - H2O sol. Polar product - P450
Methylxanthine.
Binding to the presynaptic alpha 2 release modulating receptors

44. Aztreonam is not ________ with penicillins
cross - allergenic
- acetylation - glucuron. - & sulfation - Conjugation - Polar product
Pralidoxime regenerates active cholinesterase.
Aplastic anemia (dose independent) - Gray Baby Syndrome

45. List the mechanism - clinical use - & toxicity of Bleomycin.
Digitoxin 168hrs Digoxin 40 hrs
Directly of indirectly aid conversion of plasminogen to plasmin Which cleaves thrombin and fibrin clots. (It is claimed that tPA specifically converts fibrin - bound plasminogen to plasmin.)
Ibuprofen - Naproxen - and Indomethacin
- DNA intercalator - testicular & lymphomas - Pulmonary fibrosis mild myelosuppression.

46. Does Ampicillin or Amoxicillin have a greater oral bioavailability?
AmOxicillin has greater Oral bioavailability
1. Taken daily 2. No protection against STDs 3. Raises triglycerides 4. Depression - weight gain - nausea - HTN 5. Hypercoagulable state
decrease AP duration - affects ischemic or depolarized Purkinje and ventricular system
Botulinum

47. When is Rifampin not used in combination with other drugs?
GI side effects. (Indomethacin is less toxic - more commonly used.)
Reserpine inhibits dopamine transport into vesicles - attenuating its conversion to NE by dopamine beta - hydroxylase.
1. Meningococcal carrier state 2. Chemoprophylaxis in contacts of children with H. influenzae type B
Those patients who are taking nitrates.

48. What is the memory key for Metronidazole's clinical uses?
GET on the Metro
To inhibit renal Dihydropeptidase I and decrease Imipenem inactivation in the renal tubules
- Fluoroquinolones
Beta - lactamase cleavage of Beta - lactam ring

49. How is Griseofulvin used clinically?
loop diuretics - thiazides
Mg = Must go to the bathroom.
Hypersensitivity reactions
Oral treatment of superficial infections

50. Will Hemicholinum affect the release of stored Ach during Cholinergic Stimulation
Phenothiazine (neuroleptic - antiemetic).
No - hemicholinum block the uptake of Choline and thus Ach synthesis
Terminal D- ala of cell wall replaced with D- lac; Decreased affinity
decrease myocardial O2 consumption by: 1- decreasing end diastolic volume 2- decreasing BP 3- decreasing HR 4- decreasing contractility 5- decreasing ejection time