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. Does Warfarin have a long - medium - or short half life?
Long.
Triple Therapy' 2 Nucleoside RT Inhibitors with a Protease Inhibitor
Beta 2 agonist; desired effect is the relaxation of bronchial smooth muscle (Beta 2). Use during acute exacerbation.
torsade de pointes - excessive Beta block

2. What is the clinical use for Heparin?
Immediate anticoagulation for PE - stroke - angina - MI - DVT.
Chagas' disease - American Trypanosomiasis (Trypanosoma cruzi)
cholestyramine - colestipol
Imipenem

3. Hydralazine - toxicity?
Abortifacient.
- Alkalate DNA - Brain tumors - CNS toxicity
- Nitrate - hydroxocobalamin thiosulfate
compensatory tachycardia - fluid retention - lupus - like syndrome

4. For Warfarin What is the Structure
Small lipid - soluble molecule
Yes
block voltage dependent L- type Ca2+ channels of cardiac and smooth muscle - decreasing contractility
blocks SR Ca2+ channels

5. List the specific antidote for this toxin: Copper
- Penicillamine
Antileukotriene; blocks leukotriene receptors.
Neurotoxicity - Acute renal tubular necrosis
diuretics - sympathoplegics - vasodilators - ACE inhibitors - Angiotensin II receptor inhibitors

6. Name two bile acid resins.
propanolol - esmolol - metoprolol - atenolol - timolol
Increases coumadin metabolism
Non - Nucleosides
cholestyramine - colestipol

7. Antiarrhythmic class IV- clinical use?
prevention of nodal arrhythmias (SVT)
Inhibits cGMP phosphodiesterase - casuing increased cGMP - smooth muscle relaxation in the corpus cavernosum - increased blood flow - and penile erection.
- Topo II inhibitor(GII specific) - Oat cell of Lung & prostate - & testicular - Myelosuppression & GI irritation.
- B51Naloxone / naltrexone (Narcan)

8. What is the major side effect for Ampicillin and Amoxicillin?
Hypersensitivity reactions
- Sulfonamides - furosemide - methicillin - rifampin - NSAIDS (ex. ASA)
1. Gastric ulceration 2. Bleeding 3. Hyperventilation 4. Reye's syndrome 5. Tinnitus (CN VIII)
- Chloramphenicol

9. What antimuscarinic drug is useful for the tx of asthma
Same as penicillin. Act as narrow spectrum antibiotics
Rifampin - Ethambutol - Streptomycin - Pyrazinamide - Isoniazid (INH)
Ipratropium
Prophylaxis for Influenza A - Rubella; Parkinson's disease

10. Adverse effects of Captopril?
constipation - flushing - edema - CV effects (CHF - AV block - sinus node depression) - and torsade de pointes (Bepridil)
vasodilator - increases cGMP to induce smooth muscle relaxation (arterioles>veins; afterload reduction)
Binding to the presynaptic alpha 2 release modulating receptors
fetal renal toxicity - hyperkalemia - Cough - Angioedema - Proteinuria - Taste changes - hypOtension - Pregnancy problems - Rash - Increased renin - Lower Angiotensin II (CAPTOPRIL)

11. What is the MOA of Foscarnet?
blocking the beta adrenergic receptor leads to decreased cAMP - and decreased Ca2+ flux
Inhibits Viral DNA polymerase
- Formaldehyde & formic acid - severe acidosis & retinal damage
Beta -2 agonist.

12. What physiological effects was the Anes using Atropine to tx
sedation - positive Coombs' test
- Physostigmine salicylate
Inhibition of 50S peptidyl transferase - Bacteriostatic
SLUD (salivation - Lacrimation - urination - Defecation)as well as airway secretion - GI motility - acid secretions

13. Resistance mechanisms for Cephalosporins/Penicillins
- Dimercaprol - succimer
Beta - lactamase cleavage of Beta - lactam ring
GI disturbances.
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)

14. Which drug(s) cause this reaction: Fanconi's syndrome?
Yes - it does not cross the placenta.
- Tetracycline
Gram + cocci - Haemophilus influenza - Enterobacter aerogenes - Neisseria species - P. mirabilis - E. coli - K. pneumoniae - Serratia marcescens ( HEN PEcKS )
They inhibit reuptake of NE at the nerve terminal (as does cocaine).

15. What are five toxicities associated with Tacrolimus (FK506)?
1. Significant: nephrotoxicity 2. Peripheral neuropathy 3. Hypertension 4. Pleural effusion 5. Hyperglycemia.
Binds to the Pyrophosphate Binding Site of the enzyme
viral kinase
1. Hot flashes 2. Ovarian enlargement 3. Multiple simultaneous pregnancies 4. Visual disturbances

16. What is the memory key for the effect of magnesium hydroxide overuse?
1. Hot flashes 2. Ovarian enlargement 3. Multiple simultaneous pregnancies 4. Visual disturbances
Activates antithrombin III
Mg = Must go to the bathroom.
1. Weight gain 2. Hepatotoxicity (troglitazone)

17. What is the MOA for Trimethoprim (TMP)?
Diuresis in pateints with sulfa allergy
Inhibits bacterial Dihydrofolate Reductase - Bacteriostatic
severe orthostatic hypotension - blurred vision - constipation - sexual dysfunction
RESPIre

18. What are common toxicities associated with Macrolides? (4)
- Formaldehyde & formic acid - severe acidosis & retinal damage
Severe Gram - rod infections.
GI discomfort - Acute cholestatic hepatitis - Eosinophilia - Skin rashes
Competitive inibitor of progestins at progesterone receptors.

19. Ca2+ channel blockers - clinical use?
Succinylcholine
hypertension - angina - arrhythmias
GI distress - Tooth discoloration and Inhibition of bone growth in children - Fanconi's syndrome - Photosensitivity
Prefers beta's at low doses - but at higher doses alpha agonist effects are predominantly seen.

20. What type of gout is treated with Allopurinol?
Chronic gout.
Phosphorylation by a Viral Kinase
1. Meningococcal carrier state 2. Chemoprophylaxis in contacts of children with H. influenzae type B
Inhibits CMV DNA polymerase

21. For Heparin What is the Duration of action
Nephrotoxicity (esp. with Cephalosporins) - Ototoxicity (esp. with Loop Diuretics)
Norepinephrine (Alpha1 -2 and beta 1)
Acute (hours)
Succinylcholine

22. Which cancer drugs work at the level of proteins(2)?
- Vinca alkaloids(inhibit MT) - Paclitaxel
As PABA antimetabolites that inhibit Dihydropteroate Synthase - Bacteriostatic
INH: Injures Neurons and Hepatocytes
- polymyxins

23. For Warfarin What is the Route of administration
Butyrophenone (neuroleptic).
Oral
Decrease the production of leukotrienes and protaglandins by inhibiting phospholipase A2 and expression of COX-2.
- Upper respiratory tract infections - pneumonias - STDs: Gram+ cocci (streptococcal infect in pts allergic to penicillin) - Mycoplasma - Legionella - Chlamydia - Neisseria

24. Why is Cilastatin administered with Imipenem?
To inhibit renal Dihydropeptidase I and decrease Imipenem inactivation in the renal tubules
Anaerobes
not a sulfonamide - but action is the same as furosemide
- Alkalating agent - NHL - Breast - ovary - & lung. - Myelosuppression - & hemorrhagic cystitis.

25. Which drug(s) cause this reaction: Diabetes insipidus?
- Atropine & pralidoxime
- Lithium
- Halothane - Valproic acid - acetaminophen - Amantia phalloides
Misoprostol is a PGE1 analog that increases the production and secretion of the gastic mucous barrier.

26. Ethacrynic Acid - toxicity?
With supplemental Folic Acid
NO HYPERURICEMIA - NO SULFA AllERGY; same as furosemide otherwise
- Act on same receptor - Full has greater efficacy
Staphlococcus aureus

27. Dobutamine used for the tx of shock acts on Which receptors
Verapamil - Diltiazem - Bepridil
troponin - tropomyosin system
Beta1 more than B2
Increase target cell response to insulin.

28. Which drug(s) cause this reaction: P450 induction(6)?
- Act on same receptor - Full has greater efficacy
- Barbiturates - phenytoin - carbamazipine - rifampin - griseofulvin - quinidine
Rheumatoid and osteoarthritis.
Bind cell membrane - disrupt osmotic properties - Are Cationc - Basic and act as detergents

29. K+ sparing diuretics - toxicity?
G6PD deficient individuals
1.Gram - rods of the Urinary and GI tracts (including Pseudomonas) 2.Neisseria 3. Some Gram + organisms
Md= (CpxCL)/F Cp= plas. Conc. CL=clear. F=bioaval.
hyperkalemia - endocrine effects (gynecomastia - anti - androgen)

30. How do the Protease Inhibitors work?
Cephalosporins
toxic
Ototoxicity - Hypokalemia - Dehydration - Allergy (sulfa) - Nephritis (interstitial) - Gout
Inhibt Assembly of new virus by Blocking Protease Enzyme

31. What are three complications of Warfarin usage?
1. Bleeding 2. Teratogenicity 3. Drug - drug interactions
Penicillin - G
Sildenafil fills the penis
sedation - sleep alterations

32. Common toxicities associated with Griseofulvin?
Teratogenic - Carcinogenic - Confusion - Headaches
Prevents release of mediators from mast cells. Effective only for the prophylaxis of asthma. Not effective during an acute attack.
- Chlorpromazine - thioridazine - haloperidol
Blastomyces - Coccidioides - Histoplasma - C. albicans; Hypercortisolism

33. Resistance mechanisms for Sulfonamides
Altered bacterial Dihydropteroate Synthetase - Decreased uptake - or Increased PABA synthesis
Nevirapine - Delavirdine
Small lipid - soluble molecule
Polymyxin B - Polymyxin E

34. What are the side effects of Rifampin?
Inhibits NaCl reabsorption in the early distal tubule. Decreases Ca2+ excretion.
Beta -2 agonist.
Minor hepatotoxicity - Drug interactions (activates P450)
Tubocurarine - atracurium - mivacurium - pancuronium - vecuronium - rapacuronium

35. What is the memory key for the action of Sildenafil (Viagra)?
1) Serious Gram - infections resistant to other Beta lactams 2) Meningitis (most penetrate the BBB)
Sildenafil fills the penis
amphetamine and ephedrine
Irreversibly inhibits H+/K+ ATPase in stomach parietal cells.

36. Which drug(s) cause this reaction: Torsade de pointes (2)?
- Class III antiarrhythmics (sotalol) - class IA (quinidine)
- partial agonist can have increased - decreased - /A21or equal potency as full agonist. - Potency is an independent factor.
Beta Blockers
CL= (rate of elimination of drug/ Plasma drug conc.)

37. Your patient wants an effective drug to treat his motion sickness - What would you prescribe
Scopolamine
Same as penicillin. Extended spectrum antibiotics
- Metronidazole - certain cephalosporins - procarbazine - sulfonylureas
Sotalol - Ibutilide - Bretylium - Amiodarone

38. What are the clinical indications for Azole therapy?
Epinephrine to treat anaphylaxis. Also useful if you have open angle glaucoma - asthma - or hypotension.
DHPG (dihydroxy-2- propoxymethyl guanine)
Systemic mycoses
Diuresis in pateints with sulfa allergy

39. How do spare receptors effect the Km?
thiazides - amiloride
Digitoxin 168hrs Digoxin 40 hrs
- ED 50 is less than the Km (less than 50% of receptors)
Binds Ergosterol - forms Membrane Pores that Disrupt Homeostatis

40. Procainamide - toxicity?
Penicillin - G
Vibrio cholerae Acne Chlamydia Ureaplasma Urealyticum Mycoplasma pneumoniae Borrelia burgdorferi (Lyme's) Rickettsia Tularemia
Oral treatment of superficial infections
reversible SLE- like syndrome

41. K+ sparing diuretics - clinical use?
Acetylcholinesterase; ACh is broken down into choline and acetate.
hyperaldosteronism - K+ depletion - CHF
distal convoluted tubule (early)
Useful in muscle paralysis during surgery or mechanical ventilation.

42. Which Aminoglycoside is used for Bowel Surgery ?
Neomycin
- Dimercaprol - succimer
Tricyclic antidepressant.
Fever/Chills - Hypotension - Nephrotoxicity - Arrhythmias

43. What enzyme is responsible for the degredation of Ach
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
Staphlococcus aureus
Acetylcholine esterase
- Nitrate - hydroxocobalamin thiosulfate

44. What is the category - method of use - and adverse effects of Salmeterol in Asthma treatment?
Mebendazole/Thiabendazole - Pyrantel Pamoate
Beta 2 agonist; used as a long - acting agent for prophylaxis. Adverse effects are tremor and arrhythmia.
- Alkalate DNA - Brain tumors - CNS toxicity
Oral treatment of superficial infections

45. Foscarnet does not require activation by a...
- reduction - oxy - & hydrolysis - H2O sol. Polar product - P450
Erythromycin - Azithromycin - Clarithromycin
Activates cholinergic receptors on bladder and bowel smooth muscle - alleviating post - op and neurogenic ileus and urinary retention.
viral kinase

46. Name five Antiarrhythmic drugs in class II?
Prevents the release of calcium from the sarcoplasmic reticulum of skeletal muscle.
propanolol - esmolol - metoprolol - atenolol - timolol
Fast vs. Slow Acetylators
- Airway - Breathing - Circulation - Dextrose (thiamine & narcan) - ABCD

47. How is Amphotericin B used clinically?
Wide spectrum of systemic mycoses: Cryptococcus - Blastomyces - Coccidioides - Aspergillus - Histoplasma - Candida - Mucor
- Haloperidol - chlorpromazine - reserpine - MPTP
Ataxia - Dizziness - Slurred speech
Sotalol - Ibutilide - Bretylium - Amiodarone

48. Quinidine - toxicity?
edematous states (CHF - cirrhosis - nephrotic syndrome - pulm edema) - HTN - hypercalcemia
Milk or Antacids - because divalent cations inhibit Tetracycline absorption in the gut
1. Acarbose 2. Miglitol
cinchonism: HA - tinnitus - thrombocytopenia - torsade de pointes due to increased QT interval

49. Which diuretics increase urine K+?
all except the K+ sparing diuretics Spironolactone - Triamterene - Amiloride
- Atropine & pralidoxime
WEPT: Warfarin affects the Extrinsic pathway and prolongs the PT.
Albuterol - tertbutaline

50. What is the mechanism of action of Omeprazole - Lansoprazole?
Irreversibly inhibits H+/K+ ATPase in stomach parietal cells.
Recurrent UTIs - Shigella - Salmonella - Pneumocystis carinii pneumonia
RESPIre
Short.