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 of Foscarnet?
- Dimercaprol - succimer
GET on the Metro
Activates antithrombin III
Inhibits Viral DNA polymerase

2. What is the category of drug names ending in - tidine (e.g. Cimetidine)
H2 antagonist
With supplemental Folic Acid
Lidocaine - Mexiletine - Tocainide
Malaria (P. falciparum)

3. What is the mechanism of action of Misoprostol?
Chronic (weeks or months)
TMP- SMZ (DOC) - aerosolized pentamidine
Misoprostol is a PGE1 analog that increases the production and secretion of the gastic mucous barrier.
Indirect agonist - uptake inhibitor

4. What is a possible toxicity of Ticlopidine - Clopidogrel usage?
Neutropenia (ticlopidine); reserved for those who cannot tolerate aspirin.
Decrease the production of leukotrienes and protaglandins by inhibiting phospholipase A2 and expression of COX-2.
Hemicholinium inhibits the transport of choline into the nerve - thus inhibiting formation of ACh.
Forms toxic metabolites in the bacterial cell - Bactericidal

5. Which drug(s) cause this reaction: Neuro and Nephrotoxic?
These B-2 agonists cause respiratory smooth muscle to relax.
Dopamine; causes its release from intact nerve terminals
- polymyxins
TMP- SMZ (DOC) - aerosolized pentamidine

6. What is the effect of norepinephrine on bp and pulse pressure?
Same as penicillin. Extended spectrum antibiotics
Increases mean - systolic - and diastolic bp - while there is little change in pulse pressure.
Nifedipine - Verapamil - Diltiazem
Inhibits formation of Initiation Complex - causes misreading of mRNA - Bactericidal

7. How is Vancomycin used clinically?
PT
Digitoxin 168hrs Digoxin 40 hrs
For serious - Gram + multidrug - resistant organisms
Erectile dysfunction.

8. Where does Griseofulvin deposit?
sedation - depression - nasal stuffiness - diarrhea
Keratin containing tissues - e.g. - nails
Activates antithrombin III
In treatment of malignant hyperthermia - due to concomitant use of halothane and succinylcholine. Also in neuroleptic malignant syndrome - a toxicity of antipsychotic drugs.

9. What are three clinical uses of the NSAIDs?
1. Antipyretic 2. Analgesic 3. Anti - inflammatory
Inhibits cell wall synthesis ( binds to PBP3). A monobactam
decrease AP duration - affects ischemic or depolarized Purkinje and ventricular system
Small lipid - soluble molecule

10. What are common serious side effects of Aminoglycosides and What are these associated with?
Vd= (Amt. of drug in body/ Plasma drug conc.)
Nephrotoxicity (esp. with Cephalosporins) - Ototoxicity (esp. with Loop Diuretics)
Hexamethonium is a nicotinic antagonist - and thus is a ganglionic blocker.
Inhibits platelet aggregation by irreversibly inhibiting the ADP pathway involved in the binding of fibrinogen.

11. Toxic side effects of the Azoles?
Hormone synthesis inhibition (Gynecomastia) - Liver dysfunction (Inhibits CYP450) - Fever - Chills
1. Infertility (pulsatile) 2. Prostate cancer (continuous: use with flutamide) 3. Uterine fibroids
Zidovudine (AZT) - Didanosine (ddI) - Zalcitabine (ddC) - Stavudine (d4T) - Lamivudine (3TC)
alpha -1 > alpha -2; used as a pupil dilator - vasoconstrictor - and for nasal decongestion

12. How do we stop angina?
Because they require some residual islet function.
NO AP duration effect. useful in V- tach that progresses to V- fib and in intractable SVT Last RESORT
Same as penicillin. Extended spectrum antibiotics
decrease myocardial O2 consumption by: 1- decreasing end diastolic volume 2- decreasing BP 3- decreasing HR 4- decreasing contractility 5- decreasing ejection time

13. Adverse effects of Hydrochlorothiazide?
Hypersensitivity reactions
Vibrio cholerae Acne Chlamydia Ureaplasma Urealyticum Mycoplasma pneumoniae Borrelia burgdorferi (Lyme's) Rickettsia Tularemia
hypokalemia - slight hyperlipidemia - hyperuricemia - lassitude - hypercalcemia - hyperglycemia
Penicillin - Ampicillin - Ticarcillin - Pipercillin - Imipenem - Aztreonam - Cephalosporins

14. Name three K+ sparing diuretics?
Spironolactone - Triamterene - Amiloride (the K+ STAys)
reduce levels of Angiotensin II - thereby preventing the inactivation of bradykinin (a potent vasodilator); renin level is increased
1. Weight gain 2. Hepatotoxicity (troglitazone)
- Vitamin K & fresh frozen plasma

15. Guanethidine enhances the release of Norepi?
Ataxia - Dizziness - Slurred speech
No - it inhibits the release of Nor Epi
Hypersensitivity reactions
1. Cimetadine 2. Ranitidine 3. Famotidine 4. Nizatidine

16. What are the major toxic side effects of the Cephalosporins?
first dose orthostatic hypotension - dizziness - headache
1) Hypersensitivity reactions 2) Increased nephrotoxicity of Aminoglycosides 3) Disulfiram - like reaction with ethanol (those with a methylthiotetrazole group - e.g. - cefamandole)
Botulinum
1. Cimetadine 2. Ranitidine 3. Famotidine 4. Nizatidine

17. Why would you give a drug like pancuronium or succinylcholine?
Useful in muscle paralysis during surgery or mechanical ventilation.
HSV - VZV - EBV - Mucocutaneous and Genital Herpes Lesions - Prophylaxis in Immunocompromised pts
Norepinephrine
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)

18. Furosemide - clinical use?
Headache - flushing - dyspepsia - blue - green color vision.
bradycardia - AV block - CHF
edematous states (CHF - cirrhosis - nephrotic syndrome - pulm edema) - HTN - hypercalcemia
Blocks viral penetration/uncoating; may act to buffer the pH of the endosome

19. Adverse effects of Reserpine?
WEPT: Warfarin affects the Extrinsic pathway and prolongs the PT.
Oxygen
Cell membrane Ca2+ channels of cardiac sarcomere
sedation - depression - nasal stuffiness - diarrhea

20. Ca2+ sensitizers'- site of action?
Muscarinic antagonist; competatively blocks muscarinic receptors - preventing bronchoconstriction.
troponin - tropomyosin system
Inhibits reabsorption of uric acid.
Rifampin (DOC) - minocycline

21. MOA for Penicillin (3 answers)?
Nephrotoxicity (esp. with Cephalosporins) - Ototoxicity (esp. with Loop Diuretics)
1)Binds penicillin - binding proteins 2) Blocks transpeptidase cross - linking of cell wall 3) Activates autolytic enzymes
Choline acetyltransferase
Initially vasoconstriction would increase bp - but then it acts on central alpha -2 receptors to decrease adrenergic outflow resulting in decreased bp.

22. What are Fluoroquinolones indicated for? (3)
Epinephrine
1.Gram - rods of the Urinary and GI tracts (including Pseudomonas) 2.Neisseria 3. Some Gram + organisms
Aplastic anemia (dose independent) - Gray Baby Syndrome
Flecainide - Encainide - Propafenone

23. How do the Protease Inhibitors work?
impotence - asthma - CV effects (bradycardia - CHF - AV block) - CNS effects (sedation - sleep alterations)
Peptic ulcer disease.
Inhibt Assembly of new virus by Blocking Protease Enzyme
hyperaldosteronism - K+ depletion - CHF

24. Why would dopamine be useful in treating shock?
Foscarnet = pyroFosphate analog
Blood
Receptors = D1=D2>beta>alpha - thus increasing heart rate (beta) and blood pressure (alpha vasoconstriction) while maintaining kidney perfusion (dopamine receptors)
- Atropine & pralidoxime

25. What is the specific clinical use of Indomethacin in neonates?
Indomethacin is used to close a patent ductus arteriosus.
physostigmine
Inhibition of 50S peptidyl transferase - Bacteriostatic
Milk or Antacids - because divalent cations inhibit Tetracycline absorption in the gut

26. What are three toxicities of Propylthiouracil?
Inhibits reabsorption of uric acid.
Inhibits cell wall mucopeptide formation - Bactericidal
1. Skin rash 2. Agranulocytosis (rare) 3. Aplastic anemia
dizziness - flushing - constipation (verapamil) - nausea

27. List the specific antidote for this toxin: TPA & Streptokinase
Acetaminophen has antipyretic and analgesic properties - but lacks anti - inflammatory properties.
Non - Nucleosides
1. RNA pol inhibitor 2. Revs up P450 3. Red/orange body fluids 4. Rapid resistance if used alone
- Aminocaproic acid

28. What are two types of drugs that interfere with the action of Sucralfate and why?
Useful in muscle paralysis during surgery or mechanical ventilation.
hypertension - CHF - diabetic renal disease
Sucralfate cannot work in the presence of antacids or H2 blockers because it requires an acidic environment to polymerize.
- Glucagon

29. What enzymes are inhibited by NSAIDs - acetaminophen and COX II inhibitors?
Cyclooxygenases (COX I - COX II).
troponin - tropomyosin system
- Alkalate DNA - Brain tumors - CNS toxicity
Lipoxygenase

30. What is the MOA of Aztreonam?
1. Antiandrogen 2. Nausea 3. Vomiting
SLUD (salivation - Lacrimation - urination - Defecation)as well as airway secretion - GI motility - acid secretions
fetal renal toxicity - hyperkalemia - Cough - Angioedema - Proteinuria - Taste changes - hypOtension - Pregnancy problems - Rash - Increased renin - Lower Angiotensin II (CAPTOPRIL)
Inhibits cell wall synthesis ( binds to PBP3). A monobactam

31. For Warfarin What is the Site of action
1. Tolbutamide 2. Chlorpropamide 3. Glyburide 4. Glipizide
- partial agonist can have increased - decreased - /A21or equal potency as full agonist. - Potency is an independent factor.
- Penicillin
Liver

32. MOA: Block DNA topoisomerases
Quinolones
Ld= (CpxVd)/F Cp=plasma conc. F= Bioaval.
- Corticosteroids - heparin
Premature infants - because they lack UDP- glucuronyl transferase

33. Ca2+ channel blockers - clinical use?
hypertension - angina - arrhythmias
increase AP duration - increase ERP - increase QT interval - for use When other arrhythmics fail
Neurotoxicity - Acute renal tubular necrosis
Ganciclovir is more toxic to host enzymes

34. Adverse effects of Clonidine?
Vd= (Amt. of drug in body/ Plasma drug conc.)
dry mouth - sedation - severe rebound hypertension
Yes
Digitoxin>95% Digoxin 75%

35. How does a noncompetitive antagonist effect an agonist?
- Shifts the curve down - reduces Vmax
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.
Decreases synthesis of Mycolic Acid
all except the K+ sparing diuretics Spironolactone - Triamterene - Amiloride

36. Why would a patient with cog - wheel rigidity and a shuffling gait be given benztropine?
Parkinson patients benefit from antimuscarinic agents through its inhibitory action within the indirect pathway.
- MT polymerization stabilizer - Ovarian & breast CA - Myelosupperession & hypersensitivity.
Bactericidal for: Gram + rod and cocci - Gram - cocci - and Spirochetes
hyperkalemia - endocrine effects (gynecomastia - anti - androgen)

37. What are two toxicities associated with Cyclosporine?
Giant Roundworm (Ascaris) - Hookworm (Necator/Ancylostoma) - Pinworm (Enterobius)
Receptors = D1=D2>beta>alpha - thus increasing heart rate (beta) and blood pressure (alpha vasoconstriction) while maintaining kidney perfusion (dopamine receptors)
1. Predisposes to viral infections and lymphoma 2. Nephrotoxic (preventable with mannitol diuresis)
Norepinephrine (Alpha1 -2 and beta 1)

38. Hydrochlorothiazide - mechanism?
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.
Inhibits NaCl reabsorption in the early distal tubule. Decreases Ca2+ excretion.
anticholinesterase glaucoma
aPTT (intrinsic pathway)

39. What is Metronidazole combined with for 'triple therapy'? Against What organism?
Prophylaxis for Influenza A - Rubella; Parkinson's disease
1. Suppresses organ rejection after transplantation 2. Selected autoimmune disorders.
Bismuth and Amoxicillin or Tetracycline; against Helobacter pylori
Pseudomembranous colitis (C. difficile) - fever - diarrhea

40. What is the mechanism of action of the Alpha - glucosidase inhibitors?
Heparin catalyzes the activation of antithrombin III.
Inhibit intestinal bursh border Alpha - glucosidases; delayed hydrolysis of sugars and absorption of sugars leading to decresed postprandial hyperglycemia.
- ACE inhibitors (Losartan>no cough)
Staphlococcus aureus

41. What is the category of drug names ending in - barbital (e.g. Phenobarbital)
Keratin containing tissues - e.g. - nails
GI distress - Tooth discoloration and Inhibition of bone growth in children - Fanconi's syndrome - Photosensitivity
Babiturate.
Suramin

42. For Warfarin What is the Duration of action
Chronic (weeks or months)
Antileukotriene; blocks leukotriene receptors.
- Hydralazine - Procainamide - INH - phenytoin
No. Atropine is used to reduce urgency in mild cystitis. So it would aggravate the urinary retention.

43. What type of neurological blockade would hexamethonium create?
Misoprostol is contraindicated in women of childbearing potential because it is an abortifacient.
- Topo II inhibitor(GII specific) - Oat cell of Lung & prostate - & testicular - Myelosuppression & GI irritation.
Blocks Influenza A and RubellA; causes problems with the cerebellA
Hexamethonium is a nicotinic antagonist - and thus is a ganglionic blocker.

44. Ca2+ channel blockers - toxicity?
Keratin containing tissues - e.g. - nails
cardiac depression - peripheral edema - flushing - dizziness - constipation
Carbenicillin - Piperacillin - and Ticarcillin
- inhibits HGPRT (pur. Syn.) - Luk - Lymph

45. Norepi feedbacks and inhibits the presynaptic receptor by What mechanism
Binding to the presynaptic alpha 2 release modulating receptors
Primaquine
Depolymerizes microtubules - impairing leukocyte chemotaxis and degranulation.
Terminal D- ala of cell wall replaced with D- lac; Decreased affinity

46. What is the mechanism of action of the Sulfonylureas?
Same as penicillin. Extended spectrum antibiotics
INH: Injures Neurons and Hepatocytes
Methicillin - Nafcillin - and Dicloxacillin
Close K+ channels in Beta - cell membrane leading to cell depolarization causing insulin release triggered by increase in Calcium ion influx.

47. Explain pH dependent urinary drug elimination?
- Weak Acids>Alkinalize urine(CO3) to remove more - Weak bases>acidify urine to remove more
Penicillin - G
- Estrogen receptor antagonist - Breast CA - increased endometrial CA risk
Altered bacterial Dihydropteroate Synthetase - Decreased uptake - or Increased PABA synthesis

48. What is action of insulin in the liver - in muscle - and in adipose tissue?
1. In liver - increases storage of glucose as glycogen. 2. In muscle - stimulates glycogen and protein synthesis - and K+ uptake. 3. In adipose tissue - facilitates triglyceride storage.
- partial agonist can have increased - decreased - /A21or equal potency as full agonist. - Potency is an independent factor.
1. Peptic ulcer 2. Gastritis 3. Esophageal reflux 4. Zollinger - Ellison syndrome
NO

49. What microorganisms are clinical indications for Tetracycline therapy?

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

50. How is Chloramphenical used clinically?
Rapid (seconds)
- Aminocaproic acid
- Vinca alkaloids(inhibit MT) - Paclitaxel
Meningitis (H. influenza - N. meningitidis - S. pneumoniae) - Conserative treatment due to toxicities