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. Hydrochlorothiazide - mechanism?
Inhibits NaCl reabsorption in the early distal tubule. Decreases Ca2+ excretion.
Same as penicillin. Extended spectrum antibiotics
Centrally acting alpha agonist - thus causing a decrease in central adrenergic outflow - spairing renal blood flow
Norepinephrine (Alpha1 -2 and beta 1)

2. How is Amphotericin B administered for fungal meningitis?
aPTT (intrinsic pathway)
Those patients who are taking nitrates.
Intrathecally
Liver

3. What are the indications for using amphetamine?

4. List the specific antidote for this toxin: Beta Blockers
- Glucagon
GI distress - Tooth discoloration and Inhibition of bone growth in children - Fanconi's syndrome - Photosensitivity
troponin - tropomyosin system
Pyridoxine (B6) administration

5. What are two types of drugs that interfere with the action of Sucralfate and why?
With an amino acid change of D- ala D- ala to D- ala D- lac
Sucralfate cannot work in the presence of antacids or H2 blockers because it requires an acidic environment to polymerize.
Interstitial nephritis
H2 antagonist

6. What is combined with Ampicillin - Amoxicillin - Carbenicillin - Piperacillin - and Ticarcillin to enhance their spectrum?
- Vinca alkaloids(inhibit MT) - Paclitaxel
Clavulanic acid
Oral
troponin - tropomyosin system

7. Adverse effects of Methyldopa?

8. For Heparin What is the Lab value to monitor
aPTT (intrinsic pathway)
Inhibit RT of HIV and prevent the incorporation of viral genome into the host DNA
Neutropenia (ticlopidine); reserved for those who cannot tolerate aspirin.
Chronic Hepatitis A and B - Kaposi's Sarcoma

9. These drugs acts indirectly by releasing strored catecholamines in the presynaptic terminal
acts at the proximal convoluted tubule to inhibit carbonic anhydrase. Causes self - limited sodium bicarb diuresis and reduction of total body bicarb stores.
Suramin
Penicillin - Cephalosporins - Vancomycin - Aminoglycosides - Fluoroquinolones - Metronidazole
Amphetamine and Ephedrine

10. Which diuretics increase urine Ca2+?
loop diuretics - spironolactone
Prevents the release of ACh - Which results in muscle paralysis.
- reduction - oxy - & hydrolysis - H2O sol. Polar product - P450
- Barbiturates - phenytoin - carbamazipine - rifampin - griseofulvin - quinidine

11. MOA: Block DNA topoisomerases
Quinolones
It must be Phosphorylated by Viral Thymidine Kinase
Bind cell membrane - disrupt osmotic properties - Are Cationc - Basic and act as detergents
Malaria (P. falciparum)

12. Name two bile acid resins.
Sucralfate cannot work in the presence of antacids or H2 blockers because it requires an acidic environment to polymerize.
block Na+ channels in the cortical collecting tubule
cholestyramine - colestipol
- DNA intercalator - Hodgkin's - myeloma - sarcoma - and solid tumors - Cardiotoxicity & alopecia

13. Are Ampicillin and Amoxicillin are not...
- Barbiturates - phenytoin - carbamazipine - rifampin - griseofulvin - quinidine
hypertension - CHF - diabetic renal disease
penicillinase resistant
Antileukotriene; blocks synthesis by lipoxygenase.

14. Your patient wants an effective drug to treat his motion sickness - What would you prescribe
Ataxia - Dizziness - Slurred speech
HTN - CHF - calcium stone formation - nephrogenic DI.
check PFTs - LFTs - and TFTs
Scopolamine

15. Name two classes of drugs for HIV therapy
- Metronidazole - certain cephalosporins - procarbazine - sulfonylureas
1. Tolbutamide 2. Chlorpropamide 3. Glyburide 4. Glipizide
Inhibition of 50S peptidyl transferase - Bacteriostatic
Protease Inhibitors and Reverse Transcriptase Inhibitors

16. Which drug(s) cause this reaction: Diabetes insipidus?
Interferes with microtubule function - disrupts mitosis - inhibits growth
1. Renal damage 2. Aplastic anemia 3. GI distress
Chloramphenicol - Erythromycin/macrolides - Lincomycin - Clindamycin - Streptogramins (quinupristin - dalfopristin)
- Lithium

17. What are major side effects of Methicillin - Nafcillin - and Dicloxacillin?
Hypersensitivity reactions
Inhibits formation of Initiation Complex - causes misreading of mRNA - Bactericidal
Inhibits organification and coupling of thyroid hormone synthesis. Also decreases peripheral conversion of T4 to T3.
nausea - headache - lupus - like syndrome - reflex tachycardia - angina - salt retention

18. What is the category and mechanism of action of Zafirlukast in Asthma treatment?
- Fluoroquinolones
Antileukotriene; blocks leukotriene receptors.
Diarrhea - Urination - Miosis - Bronchospasm - Bradycardia - Excitation of skeletal muscle and CNS - Lacrimation - Sweating - and Salivation = DUMBBELS; also abdominal cramping
HTN - CHF - calcium stone formation - nephrogenic DI.

19. Name the common Nucleoside Reverse Transcriptase Inhibitors
Chronic (weeks or months)
Zidovudine (AZT) - Didanosine (ddI) - Zalcitabine (ddC) - Stavudine (d4T) - Lamivudine (3TC)
- Estrogen receptor antagonist - Breast CA - increased endometrial CA risk
Rifampin - Ethambutol - Streptomycin - Pyrazinamide - Isoniazid (INH)

20. Which H2 Blocker has the most toxic effects and What are they?
Cimetidine is a potent inhibitor of P450; it also has an antiandrogenic effect and decreases renal excretion of creatinine. Other H2 blockers are relatively free of these effects.
Methylzanthine; desired effect is bronchodilation - may cause bronchodilation by inhibiting phosphodiesterase - enzyme involved in degrading cAMP (controversial).
Initially vasoconstriction would increase bp - but then it acts on central alpha -2 receptors to decrease adrenergic outflow resulting in decreased bp.
Gram - rods: Klebsiella species - Pseudomonas species - Serratia species

21. How do the Protease Inhibitors work?
Prevents release of mediators from mast cells. Effective only for the prophylaxis of asthma. Not effective during an acute attack.
Decreases synthesis of Mycolic Acid
Systemic mycoses
Inhibt Assembly of new virus by Blocking Protease Enzyme

22. What is the mechanism of action of Heparin?
DOC in diagnosing and abolishing AV nodal arrhythmias
Those patients who are taking nitrates.
Heparin catalyzes the activation of antithrombin III.
Methylxanthine.

23. Which cancer drugs work at the level of mRNA(2)?
Milk or Antacids - because divalent cations inhibit Tetracycline absorption in the gut
pulmonary fibrosis - corneal deposits - hepatotoxicity - skin deposits resulting in photodermatitis - neurologic effects - consitpation - CV (bradycardia - heart block - CHF) - and hypo - or hyperthyroidism.
narcolepsy - obesity - and attention deficit disorder (I wouldn't recommend this)
- Steroids - Tamoxifen

24. List the specific antidote for this toxin: Opioids
- N- acetylcystine
- B51Naloxone / naltrexone (Narcan)
Phenothiazine (neuroleptic - antiemetic).
Antiprotozoal: Giardia - Entamoeba - Trichomonas - Gardnerella vaginalis Anaerobes: Bacteroides - Clostridium

25. What is the mechanism of action of the Alpha - glucosidase inhibitors?
- S- phase anti - metabolite folate analogue - Luk - Lymp - sarc - RA - & psoriasis / - Reversible myelosuppression
atropine - homatropine - tropicamide
Inhibit intestinal bursh border Alpha - glucosidases; delayed hydrolysis of sugars and absorption of sugars leading to decresed postprandial hyperglycemia.
Acetylcholine esterase

26. What are two Alpha - glucosidase inhibitors?
Digitoxin 70% Digoxin 20-40%
1. Acarbose 2. Miglitol
Meningitis (H. influenza - N. meningitidis - S. pneumoniae) - Conserative treatment due to toxicities
Interferes with microtubule function - disrupts mitosis - inhibits growth

27. Esmolol - short or long acting?
very short acting
Beta - lactam antibiotics
Penicillin - Ampicillin - Ticarcillin - Pipercillin - Imipenem - Aztreonam - Cephalosporins
Gram + cocci - Proteus mirabilis - E. coli - Klebsiella pneumoniae (PEcK)

28. Ca2+ channel blockers - clinical use?
hypertension - angina - arrhythmias
No - warfarin - unlike heparin - can cross the placenta.
severe orthostatic hypotension - blurred vision - constipation - sexual dysfunction
Beta1 more than B2

29. For Warfarin What is the Ability to inhibit coagulation in vitro
thick ascending limb
No
Inhibits DNA dependent RNA polymerase
Stimulates beta adrenergic receptors

30. What is the category of drug names ending in - phylline (e.g. Theophylline)
In 4 half - lifes= (94%) T1/2 = (0.7x Vd)/CL
Penicillin - Ampicillin - Ticarcillin - Pipercillin - Imipenem - Aztreonam - Cephalosporins
Methylxanthine.
Same as penicillin. Extended spectrum antibiotics

31. List the mechanism - clinical use - & toxicity of Tamoxifen.
- Estrogen receptor antagonist - Breast CA - increased endometrial CA risk
orthostatic and exercise hypotension - sexual dysfunction - diarrhea
1. Significant: nephrotoxicity 2. Peripheral neuropathy 3. Hypertension 4. Pleural effusion 5. Hyperglycemia.
Ciprofloxacin - Norfloxacin - Ofloxacin - Grepafloxacin - Enoxacin - Nalidixic acid

32. What is the MOA for Vancomycin?
Acetylcholinesterase; ACh is broken down into choline and acetate.
decrease AP duration - affects ischemic or depolarized Purkinje and ventricular system
Diuresis in pateints with sulfa allergy
Inhibits cell wall mucopeptide formation - Bactericidal

33. What is the category - mechanism of action - and effect of Ipratroprium in Asthma treatment?
- Shifts the curve down - reduces Vmax
- Clindamycin
Nevirapine - Delavirdine
Muscarinic antagonist; competatively blocks muscarinic receptors - preventing bronchoconstriction.

34. Which individuals are predisposed to Sulfonamide - induced hemolysis?
Protease inhibitor.
Penicillin - V
blocking the beta adrenergic receptor leads to decreased cAMP - and decreased Ca2+ flux
G6PD deficient individuals

35. ACE inhibitors - clinical use?
1. Infertility (pulsatile) 2. Prostate cancer (continuous: use with flutamide) 3. Uterine fibroids
hypertension - CHF - diabetic renal disease
hypokalemia - slight hyperlipidemia - hyperuricemia - lassitude - hypercalcemia - hyperglycemia
all except the K+ sparing diuretics Spironolactone - Triamterene - Amiloride

36. What are the major structural differences between Penicillin and Cephalosporin?
No - it inhibits the release of Nor Epi
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)
carbonic anhydrase inhibitors - K+ sparing diuretics
Can affect absorption - bioavailability - or urinary excretion of other drugs by altering gastric and urinary pH or by delaying gastric emptying.

37. What are five disadvantages of Oral Contraceptives (synthetic progestins - estrogen)?
- Antipsychotics
1. Taken daily 2. No protection against STDs 3. Raises triglycerides 4. Depression - weight gain - nausea - HTN 5. Hypercoagulable state
- Sulfonamides - furosemide - methicillin - rifampin - NSAIDS (ex. ASA)
Chronic gout.

38. Antiarrhythmic class IV- primary site of action?
Saquinavir - Ritonavir - Indinavir - Nelfinavir
Carbenicillin - Piperacillin - and Ticarcillin
1. Phospholipase A2 is prevented from releasing arachidonic acid 2. Decreases protein synthesis thus lowering amount of Cyclooxygenase enzymes
AV nodal cells

39. Toxic effects of TMP include?
Methylzanthine; desired effect is bronchodilation - may cause bronchodilation by inhibiting phosphodiesterase - enzyme involved in degrading cAMP (controversial).
Antileukotriene; blocks leukotriene receptors.
impotence - asthma - CV effects (bradycardia - CHF - AV block) - CNS effects (sedation - sleep alterations)
Megaloblastic anemia - Leukopenia - Granulocytopenia

40. What is the category - desired effect - and possible mechanism of Theophylline in treating Asthma?
TMP- SMZ
Methylzanthine; desired effect is bronchodilation - may cause bronchodilation by inhibiting phosphodiesterase - enzyme involved in degrading cAMP (controversial).
Acetylates and irreversibly inhibits cyclooxygenase (COX I and COX II) to prevent the conversion of arachidonic acid to prostaglandins.
- Antipsychotics

41. List the specific antidote for this toxin: Benzodiazepines
block voltage dependent L- type Ca2+ channels of cardiac and smooth muscle - decreasing contractility
GI distress - Tooth discoloration and Inhibition of bone growth in children - Fanconi's syndrome - Photosensitivity
- Flumazenil
Aminoglycosides - Tetracyclines

42. Which drug(s) cause this reaction: Tardive dyskinesia?
reduce levels of Angiotensin II - thereby preventing the inactivation of bradykinin (a potent vasodilator); renin level is increased
- Antipsychotics
No. Atropine is used to reduce urgency in mild cystitis. So it would aggravate the urinary retention.
Muscarinic antagonist; competatively blocks muscarinic receptors - preventing bronchoconstriction.

43. What is the clinical utility of clonidine?
Treatment of hypertension - especially with renal disease (lowers bp centrally - so flow is maintained to kidney).
- Formaldehyde & formic acid - severe acidosis & retinal damage
- Alkalate DNA - Brain tumors - CNS toxicity
CL= (rate of elimination of drug/ Plasma drug conc.)

44. Acetazolamide - toxicity?
hyperchloremic metabolic acidosis - neuropathy - NH3 toxicity - sulfa allergy
Scopolamine
Similar to cyclosporine; binds to FK- binding protein - inhibiting secretion of IL-2 and other cytokines.
propanolol - esmolol - metoprolol - atenolol - timolol

45. Which cancer drugs effect nuclear DNA (4)?
Epinephrine
- Alkalating agents+cisplatin - Doxorubicin+Dactinomycin - Bleomycin - Etoposide
decrease conduction velocity - increase ERP - increase PR interval
Inhibits CMV DNA polymerase

46. What organisms does Griseofulvin target?
-100% oxygen - hyperbaric
Activates antithrombin III
For serious - Gram + multidrug - resistant organisms
Dermatophytes (tinea - ringworm)

47. What are three unwanted effects of Mifepristone?
1. Heavy bleeding 2. GI effects (n/v - anorexia) 3. Abdominal pain
dizziness - flushing - constipation (verapamil) - nausea
Na/K ATPase
1)Binds penicillin - binding proteins 2) Blocks transpeptidase cross - linking of cell wall 3) Activates autolytic enzymes

48. What is the memory key for the effect of aluminum hydroxide overuse?
Neostigmine - pyridostigmine edrophonium - physostigmine echothiophate
It must be Phosphorylated by Viral Thymidine Kinase
Immediate anticoagulation for PE - stroke - angina - MI - DVT.
AluMINIMUM amount of feces.

49. Which drug(s) cause this reaction: Tubulointerstitial Nephritis (5)?
1. Hydrocortisone 2. Predisone 3. Triamcinolone 4. Dexamethasone 5. Beclomethasone
Triple sulfas or SMZ
- Glucagon
- Sulfonamides - furosemide - methicillin - rifampin - NSAIDS (ex. ASA)

50. What is the MOA of Griseofulvin?
Glycoproteins from leukocytes that block various stages of viral RNA and DNA synthesis
Systemic mycoses
Mycobacterium tuberculosis - the only agent used as solo prophylaxis against TB
Interferes with microtubule function - disrupts mitosis - inhibits growth