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. Amiodarone - toxicity?
Similar to cyclosporine; binds to FK- binding protein - inhibiting secretion of IL-2 and other cytokines.
pulmonary fibrosis - corneal deposits - hepatotoxicity - skin deposits resulting in photodermatitis - neurologic effects - consitpation - CV (bradycardia - heart block - CHF) - and hypo - or hyperthyroidism.
- DNA intercalator - Hodgkin's - myeloma - sarcoma - and solid tumors - Cardiotoxicity & alopecia
Benzodiazepine.

2. Why would you use pralidoxime after exposure to an organophosphate?
1. Significant: nephrotoxicity 2. Peripheral neuropathy 3. Hypertension 4. Pleural effusion 5. Hyperglycemia.
Pralidoxime regenerates active cholinesterase.
- Deferoxamine
Depolymerizes microtubules - impairing leukocyte chemotaxis and degranulation.

3. Foscarnet toxicity?
Nephrotoxicity
Due to the presence of a bulkier R group
These B-2 agonists cause respiratory smooth muscle to relax.
- S- phase anti - metabolite Pyr analogue - Colon - solid tumors - & BCC/ - Irreversible myelosuppression

4. What is the mecanism of action of Sucralfate?
1. Hot flashes 2. Ovarian enlargement 3. Multiple simultaneous pregnancies 4. Visual disturbances
thiazides - amiloride
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.
As PABA antimetabolites that inhibit Dihydropteroate Synthase - Bacteriostatic

5. What is a possible result of overdose of Acetaminophen?
Overdose produces hepatic necrosis; acetaminophen metablolite depletes glutathione and forms toxic tissue adducts in liver.
Beta Blockers
1. Meningococcal carrier state 2. Chemoprophylaxis in contacts of children with H. influenzae type B
- Protamine

6. How is Acyclovir used clinically?
HSV - VZV - EBV - Mucocutaneous and Genital Herpes Lesions - Prophylaxis in Immunocompromised pts
proximal convoluted tubule
It affects beta receptors equally and is used in AV heart block (rare).
alpha -1 > alpha -2; used as a pupil dilator - vasoconstrictor - and for nasal decongestion

7. What are the clinical indications for neostigmine?
Anaerobic infections (e.g. - B. fragilis - C. perfringens)
Post - op and neurogenic ileus and urinary retention - myasthenia gravis - and reversal of neuromuscular junction blockade (post - op) through anticholinesterase activity.
Beta1 more than B2
1. Skin rash 2. Agranulocytosis (rare) 3. Aplastic anemia

8. Are penicillinase resistant
constipation - flushing - edema - CV effects (CHF - AV block - sinus node depression) - and torsade de pointes (Bepridil)
diuretics - sympathoplegics - vasodilators - ACE inhibitors - Angiotensin II receptor inhibitors
AZT - to reduce risk of Fetal Transmission
Methicillin - Nafcillin - and Dicloxacillin

9. What is the clinical use for Warfarin?
- Weak Acids>Alkinalize urine(CO3) to remove more - Weak bases>acidify urine to remove more
Chronic anticoagulation.
Post - op and neurogenic ileus and urinary retention - myasthenia gravis - and reversal of neuromuscular junction blockade (post - op) through anticholinesterase activity.
HSV - VZV - EBV - Mucocutaneous and Genital Herpes Lesions - Prophylaxis in Immunocompromised pts

10. List the specific antidote for this toxin: Methanol & Ethylene glycol
INH: Injures Neurons and Hepatocytes
1. Antiandrogen 2. Nausea 3. Vomiting
competitive inhibirot of aldosterone in the cortical collecting tubule
- Ethanol - dialysis - & fomepizole

11. Name the Protease Inhibitors (4)
- DNA intercalator - Hodgkin's - myeloma - sarcoma - and solid tumors - Cardiotoxicity & alopecia
cholestyramine - colestipol
Saquinavir - Ritonavir - Indinavir - Nelfinavir
- Tetracycline

12. Side effects of Isoniazid (INH)?
Hemolysis (if G6PD deficient) - Neurotoxicity - Hepatotoxicity - SLE- like syndrome
Methylzanthine; desired effect is bronchodilation - may cause bronchodilation by inhibiting phosphodiesterase - enzyme involved in degrading cAMP (controversial).
1. Cimetadine 2. Ranitidine 3. Famotidine 4. Nizatidine
With an amino acid change of D- ala D- ala to D- ala D- lac

13. Why does NE result in bradycardia?
bradycardia - AV block - CHF
NE increases bp - Which stimulates baroreceptors in the carotid sinus and the aorta. The CNS signals through vagal stimulation to decrease heart rate.
Sulfonamide Loop Diuretic. Inhibits ion co - transport system of thick ascending loop. Abolishes hypertonicity of the medulla - thereby preventing concentration of the urine.
Hormone synthesis inhibition (Gynecomastia) - Liver dysfunction (Inhibits CYP450) - Fever - Chills

14. 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.
Beta - lactam antibiotics
Blocks translocation - binds to the 23S rRNA of the 50S subunit - Bacteriostatic
- Isoniazid

15. What is the MOA for Carbenicillin - Piperacillin - and Ticarcillin?
1. Renal damage 2. Aplastic anemia 3. GI distress
Indomethacin is used to close a patent ductus arteriosus.
Giant Roundworm (Ascaris) - Hookworm (Necator/Ancylostoma) - Pinworm (Enterobius)
Same as penicillin. Extended spectrum antibiotics

16. For Heparin What is the Site of action
In 4 half - lifes= (94%) T1/2 = (0.7x Vd)/CL
Blood
Interferes with microtubule function - disrupts mitosis - inhibits growth
Yes

17. What is the MOA for the Fluoroquinolones?
Interstitial nephritis
Sulfonamide Loop Diuretic. Inhibits ion co - transport system of thick ascending loop. Abolishes hypertonicity of the medulla - thereby preventing concentration of the urine.
- Glucagon
Inhibit DNA Gyrase (topoisomerase II) - Bactericidal

18. List the specific antidote for this toxin: Amphetamine
Leukopenia - Neutropenia - Thrombocytopenia - Renal toxicity
Severe Gram - rod infections.
- Ammonium Chloride
Inhibit intestinal bursh border Alpha - glucosidases; delayed hydrolysis of sugars and absorption of sugars leading to decresed postprandial hyperglycemia.

19. Furosemide - class and mechanism?
Sulfonamide Loop Diuretic. Inhibits ion co - transport system of thick ascending loop. Abolishes hypertonicity of the medulla - thereby preventing concentration of the urine.
Hypersensitivity reactions
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.)
Neostigmine - pyridostigmine edrophonium - physostigmine echothiophate

20. What is the clinical use for Sildenafil (Viagra)?
Digitoxin 70% Digoxin 20-40%
Selectively inhibit cyclooxygenase (COX) isoform 2 - Which is found in inflammatory cells nad mediates inflammation and pain; spares COX-1 Which helps maintain the gastric mucosa.
Erectile dysfunction.
Neurotoxicity - Acute renal tubular necrosis

21. List the specific antidote for this toxin: Arsenic (all heavy metals)
Antibiotic - protein synthesis inhibitor.
Atropine pts are suffering from Cholinestrase inhibitor poisining (Nerve gas/Organophosphate poisining)
cardiac muscle: Verapamil>Diltiazem>Nifedipine
- Dimercaprol - succimer

22. What is the category and mechanism of action of Zafirlukast in Asthma treatment?
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.)
Antileukotriene; blocks leukotriene receptors.
Foscarnet = pyroFosphate analog
- Tricyclic antidepressants

23. Which drug(s) cause this reaction: Cutaneous flushing (4)?
- Topo II inhibitor(GII specific) - Oat cell of Lung & prostate - & testicular - Myelosuppression & GI irritation.
Prefers beta's at low doses - but at higher doses alpha agonist effects are predominantly seen.
- Niacin - Ca++ channel blockers - adenosine - vancomycin
Gram + cocci - Haemophilus influenza - Enterobacter aerogenes - Neisseria species - P. mirabilis - E. coli - K. pneumoniae - Serratia marcescens ( HEN PEcKS )

24. A 12yo patient was treated for a reaction to a bee sting - What drug provides the best coverage of sympathomimetic receptors?
- Class III antiarrhythmics (sotalol) - class IA (quinidine)
Epinephrine to treat anaphylaxis. Also useful if you have open angle glaucoma - asthma - or hypotension.
- Hydralazine - Procainamide - INH - phenytoin
Epinephirine(Alpha1 -2 and Beta 1 -2)

25. What is the mechanism of action of Mifepristone (RU486)?
Competitive inibitor of progestins at progesterone receptors.
- Isoniazid
- Dimercaprol - succimer
1. Mycobacterium tuberculosis 2. Delays resistance to Dapsone When used of Leprosy 3. Used in combination with other drugs

26. Antiarrhythmic class IV- toxicity?
1. Weight gain 2. Hepatotoxicity (troglitazone)
constipation - flushing - edema - CV effects (CHF - AV block - sinus node depression) - and torsade de pointes (Bepridil)
Stimulating beta receptors stimulates heart rate - but beta receptor induced vasodilation reduces peripheral resistance.
Nitrates

27. What is the formula for Volume of distribution (Vd)
Vd= (Amt. of drug in body/ Plasma drug conc.)
Milk or Antacids - because divalent cations inhibit Tetracycline absorption in the gut
With supplemental Folic Acid
Yes

28. What are the major toxic side effects of the Cephalosporins?
1) Hypersensitivity reactions 2) Increased nephrotoxicity of Aminoglycosides 3) Disulfiram - like reaction with ethanol (those with a methylthiotetrazole group - e.g. - cefamandole)
Albuterol - tertbutaline
Tetracycline - Doxycycline - Demeclocycline - Minocycline
Reversibly inhibit cyclooxygenase (COX I and COX II). Block prostaglandin synthesis.

29. What is the enzyme inhibited - the effect of this inhibition - and the clinical use of the antiandrogren Finasteride?
Modification via Acetylation - Adenylation - or Phosphorylation
Diarrhea
- Quinidine - quinine
Finasteride inhibits 5 Alpha - reductase - this decreases the conversion of testosterone to dihydrotestosterone - useful in BPH

30. Classes of antihypertensive drugs?
Decrease the production of leukotrienes and protaglandins by inhibiting phospholipase A2 and expression of COX-2.
diuretics - sympathoplegics - vasodilators - ACE inhibitors - Angiotensin II receptor inhibitors
Systemic mycoses
Erythromycin - Azithromycin - Clarithromycin

31. Name four HMG- CoA reductase inhibitors.
Lovastatin - Pravastatin - Simvastatin - Atorvastatin
Dopamine; causes its release from intact nerve terminals
Non - Nucleosides
decrease

32. What is the mechanism of action of Clomiphene?
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
1. Antipyretic 2. Analgesic 3. Anti - inflammatory 4. Antiplatelet drug.
decrease AP duration - affects ischemic or depolarized Purkinje and ventricular system
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.

33. Digoxin v. Digitoxin: protein binding?
Acetylcholinesterase; ACh is broken down into choline and acetate.
Blastomyces - Coccidioides - Histoplasma - C. albicans; Hypercortisolism
AV nodal cells
Digitoxin 70% Digoxin 20-40%

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

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

35. What is the major side effect for Ampicillin and Amoxicillin?
GI intolerance (nausea - diarrhea) - Hyperglycemia - Lipid abnormalities - Thrombocytopenia (Indinavir)
Anaerobes
Hypersensitivity reactions
Digoxin=urinary Digitoxin=biliary

36. What drugs target anticholinesterase
- Act on same receptor - Full has greater efficacy
Resistant Gram - infections
Neostigmine - pyridostigmine edrophonium - physostigmine echothiophate
- Lithium

37. What is the difference between the affinity for beta receptors between albuterol/terbutaline and dantroline?
Rifampin
Close K+ channels in Beta - cell membrane leading to cell depolarization causing insulin release triggered by increase in Calcium ion influx.
Acetaminophen has antipyretic and analgesic properties - but lacks anti - inflammatory properties.
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.

38. List the specific antidote for this toxin: Opioids
nausea - headache - lupus - like syndrome - reflex tachycardia - angina - salt retention
- B51Naloxone / naltrexone (Narcan)
AZT
Bleeding.

39. Which cancer drugs work at the level of mRNA(2)?
No
- Steroids - Tamoxifen
Fever/Chills - Hypotension - Nephrotoxicity - Arrhythmias
Phase 1 = prolonged depolarization - no antidote - effect potentiated by anticholinesterase; Phase 2 = repolarized but blocked - an anticholinesterase is the antidote for this phase.

40. What is the MOA of Foscarnet?
NE increases bp - Which stimulates baroreceptors in the carotid sinus and the aorta. The CNS signals through vagal stimulation to decrease heart rate.
Inhibits Viral DNA polymerase
SLUD (salivation - Lacrimation - urination - Defecation)as well as airway secretion - GI motility - acid secretions
Acetylates and irreversibly inhibits cyclooxygenase (COX I and COX II) to prevent the conversion of arachidonic acid to prostaglandins.

41. What are the Macrolides used for clinically?
The PT.
Norepinephrine
- Upper respiratory tract infections - pneumonias - STDs: Gram+ cocci (streptococcal infect in pts allergic to penicillin) - Mycoplasma - Legionella - Chlamydia - Neisseria
Neostigmine - pyridostigmine edrophonium - physostigmine echothiophate

42. List the specific antidote for this toxin: Heparin
Primaquine
- Protamine
for RSV
VACUUM your Bed Room'

43. What is the category of drug names ending in - operidol (e.g. Haloperidol)
Butyrophenone (neuroleptic).
Lipoxygenase
No
Topical and Oral - for Oral Candidiasis (Thrush)

44. Why are the Sulfonylureas inactive in IDDM (type -1)?
It acts presynaptically to increase NE release.
effective in torsade de pointes and digoxin toxicity
Because they require some residual islet function.
Epinephrine to treat anaphylaxis. Also useful if you have open angle glaucoma - asthma - or hypotension.

45. How is Leishmaniasis treated?
DOC in diagnosing and abolishing AV nodal arrhythmias
Pentavalent Antimony
AZT
nausea - headache - lupus - like syndrome - reflex tachycardia - angina - salt retention

46. What are Polymyxins used for?
competitive inhibirot of aldosterone in the cortical collecting tubule
Ceftriaxone
Epinephirine(Alpha1 -2 and Beta 1 -2)
Resistant Gram - infections

47. For Warfarin What is the Treatment for overdose
Scopolamine
is resistant
IV vitamin K and fresh frozen plasma
Hypokalemic metabolic alkalosis - hyponatremia - hyperGlycemia - hyperLipidemia - hyperUricemia - hyperCalcemia - sulfa allergy.

48. ACE inhibitors - toxicity?
Giardiasis - Amoebic dysentery (E. histolytica) - Bacterial vaginitis (Gardnerella vaginalis) - Trichomonas
Neurotoxicity - Acute renal tubular necrosis
pulmonary fibrosis - corneal deposits - hepatotoxicity - skin deposits resulting in photodermatitis - neurologic effects - consitpation - CV (bradycardia - heart block - CHF) - and hypo - or hyperthyroidism.
fetal renal damage - hyperkalemia - Cough - Angioedema - Proteinuria - Taste changes - hypOtension - Pregnancy problems - Rash - Increased renin - Lower Angiotensin II (CAPTOPRIL)

49. What is the mechanism of action of Ticlopidine - Clopidogrel
Scopolamine
Peptic ulcer disease.
Inhibits platelet aggregation by irreversibly inhibiting the ADP pathway involved in the binding of fibrinogen.
1. Antipyretic 2. Analgesic 3. Anti - inflammatory

50. Bretyllium - toxicity?
new arrhythmias - hypotension
Warfarin interferes with the normal synthesis and gamma - carboxylation of vitamin K- dependent clotting factors II - VII - IX - and X - Protein C and S via vitamin K antagonism.
Increased systolic and pulse pressure - decreased diastolic pressure - and little change in mean pressure.
Giant Roundworm (Ascaris) - Hookworm (Necator/Ancylostoma) - Pinworm (Enterobius)