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. Name the common Aminoglycosides (5)
Gentamicin - Neomycin - Amikacin - Tobramycin - Streptomycin
Disulfiram - like reaction with EtOH - Headache
bradycardia - AV block - CHF
- Tamoxifen

2. Amprotericin B ___________ the BBB
- aminoglycosides - loop diuretics - cisplatin
Does not cross
AV nodal cells
Anaerobic infections (e.g. - B. fragilis - C. perfringens)

3. Which RT inhibitors cause a Rash?
1. Predisposes to viral infections and lymphoma 2. Nephrotoxic (preventable with mannitol diuresis)
Acetylates and irreversibly inhibits cyclooxygenase (COX I and COX II) to prevent the conversion of arachidonic acid to prostaglandins.
Non - Nucleosides
Rapid (seconds)

4. What is the mecanism of action of Sucralfate?
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.
Hydralazine and Minoxidil
Primaquine
Neutropenia (ticlopidine); reserved for those who cannot tolerate aspirin.

5. What cholinergic inhibitor acts by directly inhibiting Ach release at the presynaptic terminal
Giardiasis - Amoebic dysentery (E. histolytica) - Bacterial vaginitis (Gardnerella vaginalis) - Trichomonas
Chronic gout.
Botulinum
sedation - sleep alterations

6. What is an occasional side effect of Aztreonam?
GI upset
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
The PTT.
1. Renal damage 2. Aplastic anemia 3. GI distress

7. List the mechanism - clinical use - & toxicity of Nitrosureas.
Beta antagonist.
- Vitamin K & fresh frozen plasma
- Alkalate DNA - Brain tumors - CNS toxicity
Epinephrine

8. Antiarrhythmic class II- mechanism?
Inhibits xanthine oxidase - decresing conversion of xanthine to uric acid.
Gram - rods: Klebsiella species - Pseudomonas species - Serratia species
blocking the beta adrenergic receptor leads to decreased cAMP - and decreased Ca2+ flux
- Class III antiarrhythmics (sotalol) - class IA (quinidine)

9. How is Griseofulvin used clinically?
Useful in muscle paralysis during surgery or mechanical ventilation.
Ceftriaxone
No - warfarin - unlike heparin - can cross the placenta.
Oral treatment of superficial infections

10. What class of drug is echothiophate? What is its indication?
Epinephrine to treat anaphylaxis. Also useful if you have open angle glaucoma - asthma - or hypotension.
Beta 2 agonist; used as a long - acting agent for prophylaxis. Adverse effects are tremor and arrhythmia.
anticholinesterase glaucoma
Acetylcholine esterase

11. Which drug(s) cause this reaction: Drug induced Parkinson's (4) ?
Prevents the release of Ca from SR of skeletal muscle
Gemfibrozil - Clofibrate
1. Streptokinase 2. Urokinase 3. tPA (alteplase) - APSAC (anistreplase)
- Haloperidol - chlorpromazine - reserpine - MPTP

12. Antiarrhythmic class IV- primary site of action?
AV nodal cells
Penicillin - V
NE increases bp - Which stimulates baroreceptors in the carotid sinus and the aorta. The CNS signals through vagal stimulation to decrease heart rate.
1. Antipyretic 2. Analgesic 3. Anti - inflammatory 4. Antiplatelet drug.

13. Aztreonam is not ________ with penicillins
Gram + cocci - Haemophilus influenza - Enterobacter aerogenes - Neisseria species - P. mirabilis - E. coli - K. pneumoniae - Serratia marcescens ( HEN PEcKS )
Nephrotoxicity
cross - allergenic
not a sulfonamide - but action is the same as furosemide

14. What are common serious side effects of Aminoglycosides and What are these associated with?
When pts have Low CD4+ (< 500 cells/cubic mm) or a High Viral Load
Penicillin - V
Tubocurarine - atracurium - mivacurium - pancuronium - vecuronium - rapacuronium
Nephrotoxicity (esp. with Cephalosporins) - Ototoxicity (esp. with Loop Diuretics)

15. What is used to reverse the action of Heparin?
Rapid (seconds)
Protamine Sulfate is used for rapid reversal of heparinization (positively charged molecule that binds to negatively charged heparin).
Alpha -1 antagonist
Aplastic anemia (dose independent) - Gray Baby Syndrome

16. List the specific antidote for this toxin: Cyanide
Beta -2 agonist.
Erectile dysfunction.
NO
- Nitrate - hydroxocobalamin thiosulfate

17. For Heparin What is the Ability to inhibit coagulation in vitro
Reversibly inhibit cyclooxygenase (COX I and COX II). Block prostaglandin synthesis.
Binding to the presynaptic alpha 2 release modulating receptors
hyperaldosteronism - K+ depletion - CHF
Yes

18. Name four HMG- CoA reductase inhibitors.
Leukotrienes increasing bronchial tone.
1. Gastric ulceration 2. Bleeding 3. Hyperventilation 4. Reye's syndrome 5. Tinnitus (CN VIII)
Lovastatin - Pravastatin - Simvastatin - Atorvastatin
Reversibly inhibit cyclooxygenase (COX I and COX II). Block prostaglandin synthesis.

19. What are Methicillin - Nafcillin - and Dicloxacillin used for clinically?
Mebendazole/Thiabendazole - Pyrantel Pamoate
hypokalemia - slight hyperlipidemia - hyperuricemia - lassitude - hypercalcemia - hyperglycemia
- Hypersensitivity reactions - Hemolysis - Nephrotoxicity (tubulointerstitial nephritis) - Kernicterus in infants Displace other drugs from albumin (e.g. - warfarin)
Staphlococcus aureus

20. Mannitol - mechanism?
Only in limited amounts
CMV Retinitis in IC pts When Ganciclovir fails
osmotic diuretic - increase tubular fluid osmolarity - thereby increasing urine flow
Prevents the release of calcium from the sarcoplasmic reticulum of skeletal muscle.

21. MOA for Penicillin (3 answers)?
1)Binds penicillin - binding proteins 2) Blocks transpeptidase cross - linking of cell wall 3) Activates autolytic enzymes
Hormone synthesis inhibition (Gynecomastia) - Liver dysfunction (Inhibits CYP450) - Fever - Chills
Succinylcholine
troponin - tropomyosin system

22. Which diuretics cause acidosis?
carbonic anhydrase inhibitors - K+ sparing diuretics
No - warfarin - unlike heparin - can cross the placenta.
Pregnant women - Children; because animal studies show Damage to Cartilage
cyanide toxicity (releases CN)

23. How does a noncompetitive antagonist effect an agonist?
Quinolones
- Shifts the curve down - reduces Vmax
Chronic gout.
1. Hydrocortisone 2. Predisone 3. Triamcinolone 4. Dexamethasone 5. Beclomethasone

24. For Warfarin What is the Treatment for overdose
cortical collecting tubule
IV vitamin K and fresh frozen plasma
prevention of nodal arrhythmias (SVT)
- Normalize K+ - Lidocaine - & Anti - dig Mab

25. What is Imipenem always administered with?
- Act on same receptor - Full has greater efficacy
1. Pioglitazone 2. Rosiglitazone.
1. Tolbutamide 2. Chlorpropamide 3. Glyburide 4. Glipizide
Cilastatin

26. What is Niclosamide used for?
- Glucocorticoid withdrawal
increase AP duration - increase ERP - increase QT interval - for use When other arrhythmics fail
Constant FRACTION eliminated per unit time.(exponential)
Cestode/tapeworm (e.g. - D. latum - Taenia species Except Cysticercosis

27. What is the MOA of the RT Inhibitors?
- ACE inhibitors (Losartan>no cough)
Cilastatin
Inhibit RT of HIV and prevent the incorporation of viral genome into the host DNA
Reversible block of histamine H2 receptors

28. What is Metronidazole used for clinically?
Inhibits platelet aggregation by irreversibly inhibiting the ADP pathway involved in the binding of fibrinogen.
Saquinavir - Ritonavir - Indinavir - Nelfinavir
Antiprotozoal: Giardia - Entamoeba - Trichomonas - Gardnerella vaginalis Anaerobes: Bacteroides - Clostridium
Hypersensitivity reactions

29. If a patient is given hexamethonium - What would happen to his/her heart rate?
Nonspecific beta - agonist; desired effect is the relaxation of bronchial smooth muscle (Beta 2). Adverse effect is tachycardia (Beta 1).
- Ethosuxamide - sulfonamides - lamotrigine
It would increase to ~ 100 beats/min. Both sympathetic and vagal stimulation would be knocked out - but the SA node has an intrinsic pace of 100 beats/min - Which is normally checked by vagal stimulation.
Giant Roundworm (Ascaris) - Hookworm (Necator/Ancylostoma) - Pinworm (Enterobius)

30. What is the MOA for the Aminoglycosides?
DOC in diagnosing and abolishing AV nodal arrhythmias
Inhibits formation of Initiation Complex - causes misreading of mRNA - Bactericidal
Rapid (seconds)
Only in limited amounts

31. Antimicrobial prophylaxis for a history of recurrent UTIs
When pts have Low CD4+ (< 500 cells/cubic mm) or a High Viral Load
Flecainide - Encainide - Propafenone
Fever/Chills - Hypotension - Nephrotoxicity - Arrhythmias
TMP- SMZ

32. What is the MOA for Nystatin?
Depolymerizes microtubules - impairing leukocyte chemotaxis and degranulation.
Ganciclovir is more toxic to host enzymes
Binds ergosterol - Disrupts fungal membranes
decrease

33. Which RT inhibitor causes Megaloblastic Anemia?
AZT
Rapid (seconds)
- EDTA - dimercaprol - succimer - & penicillamine
Pituitary hormone.

34. What is the mechanism of action of Allopurinol used to treat chronic gout?
- Penicillamine
Inhibits xanthine oxidase - decresing conversion of xanthine to uric acid.
CMV Retinitis in IC pts When Ganciclovir fails
1. Meningococcal carrier state 2. Chemoprophylaxis in contacts of children with H. influenzae type B

35. Which diuretics increase urine NaCl?
all of them
- Class III antiarrhythmics (sotalol) - class IA (quinidine)
GI distress - Skin rash - and Seizures at high plasma levels
- Alkalating agent - NHL - Breast - ovary - & lung. - Myelosuppression - & hemorrhagic cystitis.

36. List the specific antidote for this toxin: Anticholinesterases (organophosphate.)
- Deferoxamine
- Tricyclic antidepressants
- Atropine & pralidoxime
None. No - because atropine would block the postganglionic muscarinic receptors involved in sweat gland stimulation.

37. Explain differences between full and partial agonists(2).
Decreased uptake or Increased transport out of cell
- Act on same receptor - Full has greater efficacy
CMV - esp in Immunocompromised patients
Zidovudine (AZT) - Didanosine (ddI) - Zalcitabine (ddC) - Stavudine (d4T) - Lamivudine (3TC)

38. What is the MOA for Ampicillin and Amoxicillin?
Methylxanthine.
1. Gastric ulceration 2. Bleeding 3. Hyperventilation 4. Reye's syndrome 5. Tinnitus (CN VIII)
RESPIre
Same as penicillin. Extended spectrum antibiotics

39. Acetazolamide - mechanism?
Activates cholinergic receptors on bladder and bowel smooth muscle - alleviating post - op and neurogenic ileus and urinary retention.
- Physostigmine salicylate
Gram + - Gram - - Norcardia - Chlamydia
acts at the proximal convoluted tubule to inhibit carbonic anhydrase. Causes self - limited sodium bicarb diuresis and reduction of total body bicarb stores.

40. What is Nifurtimox administered for?

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

41. Why is pyridostigmine effective in the treatment of myasthenia gravis?
vasodilator - increases cGMP to induce smooth muscle relaxation (arterioles>veins; afterload reduction)
As an anticholinesterase it increases endogenous ACh and thus increases strength.
- Quinidine - quinine
1. Cimetadine 2. Ranitidine 3. Famotidine 4. Nizatidine

42. What are four advantages of newer low - molecular - weight heparins (Enoxaparin)?
Reversibly inhibits cyclooxygenase - mostly in CNS. Inactivated peripherally.
1. Better bioavailability 2. 2 to 4 times longer half life 3. Can be administered subcutaneously 4. Does not require laboratory monitoring
- Infections - Trauma - Seizures - CO - Overdose - Metabolic - Alcohol (IT'S COMA)
torsade de pointes - excessive Beta block

43. What is the category - method of use - and adverse effects of Salmeterol in Asthma treatment?
Beta 2 agonist; used as a long - acting agent for prophylaxis. Adverse effects are tremor and arrhythmia.
Milk or Antacids - because divalent cations inhibit Tetracycline absorption in the gut
Fever/Chills - Hypotension - Nephrotoxicity - Arrhythmias
Well tolerated in general but occasionally - Nephrotoxicity - Ototoxicity - Thrombophlebitis - diffuse flushing='Red Man Syndrome'

44. What are common toxicities related to Vancomycin therapy?

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

45. What is the MOA of Ribavirin?
- Oxalic acid - Acidosis & nephrotoxicity
Aminoglycosides - Tetracyclines
Inhibits IMP Dehydrogenase (competitively) - and therefore blocks Guanine Nucleotide synthesis
Norepinephrine

46. What is the mecanism of action - effective period - and ineffective period of use for Cromolyn in treating Asthma?
- S- phase anti - metabolite Pyr analogue - Colon - solid tumors - & BCC/ - Irreversible myelosuppression
Triple Therapy' 2 Nucleoside RT Inhibitors with a Protease Inhibitor
Beta lactams - inhibit cell wall synthesis - Bactericidal
Prevents release of mediators from mast cells. Effective only for the prophylaxis of asthma. Not effective during an acute attack.

47. Furosemide - toxicity? (OH DANG)
For serious - Gram + multidrug - resistant organisms
Ototoxicity - Hypokalemia - Dehydration - Allergy (sulfa) - Nephritis (interstitial) - Gout
Disulfiram - like reaction with EtOH - Headache
GnRH analog with agonist properties When used in pulsatile fashion and antagonist properties When used in continuous fashion - causing a transient initial burst of LH and FSH

48. Which drug(s) cause this reaction: Anaphylaxis?
all of them
- Penicillin
1. Bleeding 2. Thrombocytopenia 3. Drug - drug interactions
Succinylcholine

49. Ca2+ sensitizers'- site of action?
troponin - tropomyosin system
Binds to the Pyrophosphate Binding Site of the enzyme
IV vitamin K and fresh frozen plasma
Acute coronary syndrome; coronary stenting. Decreases the incidence or recurrence of thrombotic stroke.

50. Would blockade of muscarininc receptors in the bladder be useful in treating urinary retention?
No. Atropine is used to reduce urgency in mild cystitis. So it would aggravate the urinary retention.
- Daunorubicin & Doxorubicin
- DNA intercalator - Hodgkin's - myeloma - sarcoma - and solid tumors - Cardiotoxicity & alopecia
Neutropenia (ticlopidine); reserved for those who cannot tolerate aspirin.