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. How does NE modulate its own release? What other neurotransmitter has this same effect?
NE acts presynaptically on alpha -2 receptors to inhibit its own release. ACh also acts presynaptically through M1 receptors to inhibit NE release.
- Constant AMOUNT eliminated per unit time. - Etoh & ASA
Atropine would also block the receptors in the ciliary muscle - causing an impairment in accommodation (cycloplegia).
loop diuretics - thiazides

2. What is the category of drug names ending in - cycline (e.g. Tetracycline)
Nephrotoxicity
Rare.
Inhibit DNA Gyrase (topoisomerase II) - Bactericidal
Antibiotic - protein synthesis inhibitor.

3. Why are the Sulfonylureas inactive in IDDM (type -1)?
Because they require some residual islet function.
Saquinavir - Ritonavir - Indinavir - Nelfinavir
Prevents release of mediators from mast cells. Effective only for the prophylaxis of asthma. Not effective during an acute attack.
No - warfarin - unlike heparin - can cross the placenta.

4. What type of gout is treated with Colchicine?
- inhibits HGPRT (pur. Syn.) - Luk - Lymph
- Constant AMOUNT eliminated per unit time. - Etoh & ASA
Acute gout.
Potent immunosuppressive used in organ transplant recipients.

5. Name two classes of drugs for HIV therapy
- EDTA - dimercaprol - succimer - & penicillamine
Digitoxin 70% Digoxin 20-40%
Protease Inhibitors and Reverse Transcriptase Inhibitors
Methylxanthine.

6. What is the MOA for the Cephalosporins?
Beta lactams - inhibit cell wall synthesis - Bactericidal
Short.
- Cloazapine - carbamazapine - colchicine - PTU
In 4 half - lifes= (94%) T1/2 = (0.7x Vd)/CL

7. List the mechanism - clinical use - & toxicity of Cyclophosphamide.
- Alkalating agent - NHL - Breast - ovary - & lung. - Myelosuppression - & hemorrhagic cystitis.
sedation - depression - nasal stuffiness - diarrhea
No - warfarin - unlike heparin - can cross the placenta.
CL= (rate of elimination of drug/ Plasma drug conc.)

8. What is the mechanism of action and clinical use of the antiandrogen Flutamide?
Long.
1. Bleeding 2. Thrombocytopenia 3. Drug - drug interactions
Hydralazine and Minoxidil
Flutamide is a nonsteroidal competitive inhibitor of androgens at the testosterone receptor - used in prostate carcinoma.

9. What is a Ribavirin toxicity?
Oxygen
- Topo II inhibitor(GII specific) - Oat cell of Lung & prostate - & testicular - Myelosuppression & GI irritation.
- Flumazenil
Hemolytic anemia

10. What are two toxicities of the Glitazones?
1. Weight gain 2. Hepatotoxicity (troglitazone)
Reversible block of histamine H2 receptors
Keratin containing tissues - e.g. - nails
Neomycin

11. Antiarrhythmic class IV- clinical use?
prevention of nodal arrhythmias (SVT)
Beta antagonist.
Gemfibrozil - Clofibrate
Acute coronary syndrome; coronary stenting. Decreases the incidence or recurrence of thrombotic stroke.

12. Resistance mechanisms for Cephalosporins/Penicillins
Heparin catalyzes the activation of antithrombin III.
Beta - lactamase cleavage of Beta - lactam ring
These B-2 agonists cause respiratory smooth muscle to relax.
With supplemental Folic Acid

13. What is the category of drug names ending in - azine (e.g. Chlorpromazine)
Phenothiazine (neuroleptic - antiemetic).
Epinephrine
Primaquine
Constant FRACTION eliminated per unit time.(exponential)

14. List the specific antidote for this toxin: Copper
Overdose produces hepatic necrosis; acetaminophen metablolite depletes glutathione and forms toxic tissue adducts in liver.
- Penicillamine
severe orthostatic hypotension - blurred vision - constipation - sexual dysfunction
Bethanechol - Neostigmine - physostigmine

15. How do we stop angina?
Flecainide - Encainide - Propafenone
Antibiotic - protein synthesis inhibitor.
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.)
decrease myocardial O2 consumption by: 1- decreasing end diastolic volume 2- decreasing BP 3- decreasing HR 4- decreasing contractility 5- decreasing ejection time

16. What is the MOA of Amantadine?
Blocks viral penetration/uncoating; may act to buffer the pH of the endosome
Rifampin - Ethambutol - Streptomycin - Pyrazinamide - Isoniazid (INH)
1. Streptokinase 2. Urokinase 3. tPA (alteplase) - APSAC (anistreplase)
Choline acetyltransferase

17. What are the Macrolides used for clinically?
- Clindamycin
- Upper respiratory tract infections - pneumonias - STDs: Gram+ cocci (streptococcal infect in pts allergic to penicillin) - Mycoplasma - Legionella - Chlamydia - Neisseria
Lidocaine - Mexiletine - Tocainide
- Penicillin

18. MOA: Block cell wall synthesis by inhib. Peptidoglycan cross - linking (7)
post MI and digitalis induced arrhythmias
Penicillin - Ampicillin - Ticarcillin - Pipercillin - Imipenem - Aztreonam - Cephalosporins
Fever/Chills - Hypotension - Nephrotoxicity - Arrhythmias
Gentamicin - Neomycin - Amikacin - Tobramycin - Streptomycin

19. What neurotransmitter does Amantadine affect? How does it influence this NT?
Inhibits NaCl reabsorption in the early distal tubule. Decreases Ca2+ excretion.
- S- phase anti - metabolite Pyr analogue - Colon - solid tumors - & BCC/ - Irreversible myelosuppression
Onchocerciasis ('river blindness'-- rIVER- mectin)
Dopamine; causes its release from intact nerve terminals

20. Adenosine - clinical use?
Botulinum
1. Antipyretic 2. Analgesic 3. Anti - inflammatory 4. Antiplatelet drug.
DOC in diagnosing and abolishing AV nodal arrhythmias
narcolepsy - obesity - and attention deficit disorder (I wouldn't recommend this)

21. Antimicrobial prophylaxis for a history of recurrent UTIs
H2 antagonist
Megaloblastic anemia - Leukopenia - Granulocytopenia
NO HYPERURICEMIA - NO SULFA AllERGY; same as furosemide otherwise
TMP- SMZ

22. Adverse effects of Nifedipine - verapamil?
It inhibits release of NE.
Binds to cyclophilins (peptidyl proline cis - trans isomerase) - blocking the differentiation and activation of T cells mainly by inhibiting the production of IL-2 and its receptor.
Ca2+ (Loops Lose calcium)
dizziness - flushing - constipation (verapamil) - nausea

23. What are three possible complications of Heparin therapy?
1. Bleeding 2. Thrombocytopenia 3. Drug - drug interactions
GET on the Metro
for RSV
Acute gout.

24. Furosemide - toxicity? (OH DANG)
Ototoxicity - Hypokalemia - Dehydration - Allergy (sulfa) - Nephritis (interstitial) - Gout
Activates cholinergic receptors on bladder and bowel smooth muscle - alleviating post - op and neurogenic ileus and urinary retention.
Quinidine - Amiodarone - Procainamide - Disopyramide
Irreversibly inhibits H+/K+ ATPase in stomach parietal cells.

25. MOA: Block mRNA synthesis
- Chloramphenicol
check PFTs - LFTs - and TFTs
Rifampin
hyperchloremic metabolic acidosis - neuropathy - NH3 toxicity - sulfa allergy

26. Which RT inhibitors cause a Rash?
Dry flushed skin - due to inhibition of sympathetic post - ganglionic blockade on muscarinic receptors of sweat glands. All others are opposite of What would be expected.
Non - Nucleosides
- Daunorubicin & Doxorubicin
GI discomfort

27. Antiarrhythmic class IB- toxicity?
local anesthetic. CNS stimulation or depression. CV depression.
1. Peptic ulcer 2. Gastritis 3. Esophageal reflux 4. Zollinger - Ellison syndrome
Acetylates and irreversibly inhibits cyclooxygenase (COX I and COX II) to prevent the conversion of arachidonic acid to prostaglandins.
- Chloramphenicol - benzene - NSAIDS - PTU - phenytoin

28. Which drug(s) cause this reaction: Photosensitivity(3)?
Ceftriaxone
Inhibits organification and coupling of thyroid hormone synthesis. Also decreases peripheral conversion of T4 to T3.
- Tetracycline - amiodarone - sulfonamides
decrease

29. Hydrochlorothiazide - clinical use?
YES
- acetylation - glucuron. - & sulfation - Conjugation - Polar product
HTN - CHF - calcium stone formation - nephrogenic DI.
Blocks Norepi - but not Dopamine

30. List the mechanism - clinical use - & toxicity of Busulfan.
Albuterol - tertbutaline
- Alkalates DNA - CML - Pulmonary fibrosis hyperpigmentation
- Niacin - Ca++ channel blockers - adenosine - vancomycin
- Methotrexate - 5 FU - 6 mercaptopurine

31. Do Tetracyclines penetrate the CNS?
- Airway - Breathing - Circulation - Dextrose (thiamine & narcan) - ABCD
- S- phase anti - metabolite Pyr analogue - Colon - solid tumors - & BCC/ - Irreversible myelosuppression
Only in limited amounts
Diuresis in pateints with sulfa allergy

32. What is the mecanism of action - effective period - and ineffective period of use for Cromolyn in treating Asthma?
Prevents release of mediators from mast cells. Effective only for the prophylaxis of asthma. Not effective during an acute attack.
amphetamine and ephedrine
Inhibits CMV DNA polymerase
Reserpine inhibits dopamine transport into vesicles - attenuating its conversion to NE by dopamine beta - hydroxylase.

33. What are two Alpha - glucosidase inhibitors?
Penicillin - V
Inhibits organification and coupling of thyroid hormone synthesis. Also decreases peripheral conversion of T4 to T3.
fetal renal damage - hyperkalemia - Cough - Angioedema - Proteinuria - Taste changes - hypOtension - Pregnancy problems - Rash - Increased renin - Lower Angiotensin II (CAPTOPRIL)
1. Acarbose 2. Miglitol

34. IV Penicillin
Penicillin - G
reduce levels of Angiotensin II - thereby preventing the inactivation of bradykinin (a potent vasodilator); renin level is increased
Beta adrenergic receptors and Ca2+ channels (stimulatory)
- Airway - Breathing - Circulation - Dextrose (thiamine & narcan) - ABCD

35. What are common side effects of RT Inhibitors?
1. Taken daily 2. No protection against STDs 3. Raises triglycerides 4. Depression - weight gain - nausea - HTN 5. Hypercoagulable state
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.
BM suppression (neutropenia - anemia) - Peripheral neuropathy
- Lithium

36. What is the mechanism of action of Cyclosporine?
Binds to cyclophilins (peptidyl proline cis - trans isomerase) - blocking the differentiation and activation of T cells mainly by inhibiting the production of IL-2 and its receptor.
Blastomyces - Coccidioides - Histoplasma - C. albicans; Hypercortisolism
troponin - tropomyosin system
Meningitis (H. influenza - N. meningitidis - S. pneumoniae) - Conserative treatment due to toxicities

37. What is the category of drug names ending in - azepam (e.g. Diazepam)
Blocking muscarinic receptors in the circular fibers of the eye - results in unopposed action of radial muscles to dilate.
Increase target cell response to insulin.
Rash - Pseudomembranous colitis
Benzodiazepine.

38. What are common toxicities associated with Tetracyclines?

39. For Warfarin What is the Site of action
- Upper respiratory tract infections - pneumonias - STDs: Gram+ cocci (streptococcal infect in pts allergic to penicillin) - Mycoplasma - Legionella - Chlamydia - Neisseria
Inhibits cGMP phosphodiesterase - casuing increased cGMP - smooth muscle relaxation in the corpus cavernosum - increased blood flow - and penile erection.
Liver
Tubocurarine - atracurium - mivacurium - pancuronium - vecuronium - rapacuronium

40. What musculo - skeletal side effects in Adults are associated with Floroquinolones?
Tendonitis and Tendon rupture
Blocks Norepi - but not Dopamine
Tricyclic antidepressant.
- Class III antiarrhythmics (sotalol) - class IA (quinidine)

41. Digoxin v. Digitoxin: bioavailability?
- reduction - oxy - & hydrolysis - H2O sol. Polar product - P450
Oral
Digitoxin>95% Digoxin 75%
Meningitis (H. influenza - N. meningitidis - S. pneumoniae) - Conserative treatment due to toxicities

42. What is a common drug interaction associated with Griseofulvin?
Heparin catalyzes the activation of antithrombin III.
Increases coumadin metabolism
vasodilator - increases cGMP to induce smooth muscle relaxation (arterioles>veins; afterload reduction)
No - it inhibits the release of Nor Epi

43. Which individuals are predisposed to Sulfonamide - induced hemolysis?
G6PD deficient individuals
As PABA antimetabolites that inhibit Dihydropteroate Synthase - Bacteriostatic
Mebendazole/Thiabendazole - Pyrantel Pamoate
impotence - asthma - CV effects (bradycardia - CHF - AV block) - CNS effects (sedation - sleep alterations)

44. Which Tetracycline is used in patients with renal failure? / Why?
Terminal D- ala of cell wall replaced with D- lac; Decreased affinity
Hexamethonium is a nicotinic antagonist - and thus is a ganglionic blocker.
Pregnant women - Children; because animal studies show Damage to Cartilage
Doxycycline - because it is fecally eliminated

45. What is the clincial use for Misoprostol?
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.
Staphlococcus aureus
Prevention of NSAID- induced peptic ulcers - maintains a PDA.
Ceftriaxone

46. Cocaine casues vasoconstriction and local anesthesia by What mechanism
Nucleosides
Indirect agonist - uptake inhibitor
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.
Acute gout.

47. As an Anes you want to use a depolarizing neuromuscular blocking drug on your pt - What do you use
Dopamine; causes its release from intact nerve terminals
Succinylcholine
proximal convoluted tubule - thin descending limb - and collecting duct
Dermatophytes (tinea - ringworm)

48. What is the MOA of Isoniazid (INH)?
- Lithium
- Physostigmine salicylate
Decreases synthesis of Mycolic Acid
1. Hot flashes 2. Ovarian enlargement 3. Multiple simultaneous pregnancies 4. Visual disturbances

49. What is Ketoconazole specifically used for?
Ca2+ (Loops Lose calcium)
Blastomyces - Coccidioides - Histoplasma - C. albicans; Hypercortisolism
Corticosteroids; prevent production of leukotrienes from arachodonic acid by blocking phospholipase A2. Drugs of choice in a patient with status asthmaticus (in combination with albuterol.)
Due to the presence of a bulkier R group

50. What enzyme is responsible for the production of Ach from Acetyl CoA and Choline
Methylation of rRNA near Erythromycin's ribosome binding site
Choline acetyltransferase
GI distress - Skin rash - and Seizures at high plasma levels
Protease Inhibitors and Reverse Transcriptase Inhibitors