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 category - desired effect - and possible mechanism of Theophylline in treating Asthma?
decrease conduction velocity - increase ERP - increase PR interval
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
Gram + cocci - Proteus mirabilis - E. coli - Klebsiella pneumoniae (PEcK)
Methylzanthine; desired effect is bronchodilation - may cause bronchodilation by inhibiting phosphodiesterase - enzyme involved in degrading cAMP (controversial).

2. What is the MOA for the Aminoglycosides?
Finasteride inhibits 5 Alpha - reductase - this decreases the conversion of testosterone to dihydrotestosterone - useful in BPH
Binds 30S subunit and prevents attachment of aminoacyl - tRNA - Bacteriostatic
Inhibits formation of Initiation Complex - causes misreading of mRNA - Bactericidal
Interferes with microtubule function - disrupts mitosis - inhibits growth

3. Reserpine will block the syntheis of this drug and but not its precursor.
- Formaldehyde & formic acid - severe acidosis & retinal damage
Blocks Norepi - but not Dopamine
None. No - because atropine would block the postganglionic muscarinic receptors involved in sweat gland stimulation.
Atropine pts are suffering from Cholinestrase inhibitor poisining (Nerve gas/Organophosphate poisining)

4. What are Aminoglycosides used for clinically?
Inhibition of 50S peptidyl transferase - Bacteriostatic
- Fluoroquinolones
alpha -1 > alpha -2; used as a pupil dilator - vasoconstrictor - and for nasal decongestion
Severe Gram - rod infections.

5. What is the MOA for the Macrolides?
Give an antichloinesterase - neostigmine - edrophonium - etc
distal convoluted tubule (early)
Blocks translocation - binds to the 23S rRNA of the 50S subunit - Bacteriostatic
Carbachol - pilocarpine - physostigmine - echothiophate

6. What is the mechanism of action of the Sulfonylureas?
Close K+ channels in Beta - cell membrane leading to cell depolarization causing insulin release triggered by increase in Calcium ion influx.
- Upper respiratory tract infections - pneumonias - STDs: Gram+ cocci (streptococcal infect in pts allergic to penicillin) - Mycoplasma - Legionella - Chlamydia - Neisseria
Clavulanic acid
- Steroids - Tamoxifen

7. What cholinomimetics might your pt be taking for his glaucoma
dry mouth - sedation - severe rebound hypertension
It inhibits release of NE.
Misoprostol is contraindicated in women of childbearing potential because it is an abortifacient.
Carbachol - pilocarpine - physostigmine - echothiophate

8. What is the MOA for Clindamycin?
Blocks viral penetration/uncoating; may act to buffer the pH of the endosome
TCA
Chagas' disease - American Trypanosomiasis (Trypanosoma cruzi)
Blocks Peptide Bond formation at the 50S subunit - Bacteriostatic

9. What are common toxicities associated with Tetracyclines?

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

10. Hydralazine - toxicity?
compensatory tachycardia - fluid retention - lupus - like syndrome
Penicillin - Cephalosporins - Vancomycin - Aminoglycosides - Fluoroquinolones - Metronidazole
Nucleosides
Hydralazine and Minoxidil

11. Specifically - How does Foscarnet inhibit viral DNA pol?
Protease Inhibitors and Reverse Transcriptase Inhibitors
Beta - lactamase cleavage of Beta - lactam ring
Binds to the Pyrophosphate Binding Site of the enzyme
Chloramphenicol - Erythromycin/macrolides - Lincomycin - Clindamycin - Streptogramins (quinupristin - dalfopristin)

12. Toxic side effects of the Azoles?
Phenothiazine (neuroleptic - antiemetic).
Receptors = D1=D2>beta>alpha - thus increasing heart rate (beta) and blood pressure (alpha vasoconstriction) while maintaining kidney perfusion (dopamine receptors)
Hormone synthesis inhibition (Gynecomastia) - Liver dysfunction (Inhibits CYP450) - Fever - Chills
HSV - VZV - EBV - Mucocutaneous and Genital Herpes Lesions - Prophylaxis in Immunocompromised pts

13. What type of gout is treated with Allopurinol?
Digitoxin 168hrs Digoxin 40 hrs
increased AP duration - increased ERP increased QT interval. Atrial and ventricular.
Alpha -1 antagonist
Chronic gout.

14. What is the MOA for Rifampin?
Beta antagonist.
decrease myocardial O2 consumption by: 1- decreasing end diastolic volume 2- decreasing BP 3- decreasing HR 4- decreasing contractility 5- decreasing ejection time
Inhibits DNA dependent RNA polymerase
1) Hypersensitivity reactions 2) Increased nephrotoxicity of Aminoglycosides 3) Disulfiram - like reaction with ethanol (those with a methylthiotetrazole group - e.g. - cefamandole)

15. What is the specific clinical use of Indomethacin in neonates?
Treatment of hypertension - especially with renal disease (lowers bp centrally - so flow is maintained to kidney).
Indomethacin is used to close a patent ductus arteriosus.
Resistant Gram - infections
is resistant

16. What is the memory key for Metronidazole's clinical uses?
Cryptococcal meningitis in AIDS patients and Candidal infections of all types
GET on the Metro
1. Hydrocortisone 2. Predisone 3. Triamcinolone 4. Dexamethasone 5. Beclomethasone
Inhibit intestinal bursh border Alpha - glucosidases; delayed hydrolysis of sugars and absorption of sugars leading to decresed postprandial hyperglycemia.

17. Name four HMG- CoA reductase inhibitors.
Lovastatin - Pravastatin - Simvastatin - Atorvastatin
Tricyclic antidepressant.
-100% oxygen - hyperbaric
Ca2+ (Loops Lose calcium)

18. Ca2+ channel blockers - site of action?
- Triggers apoptosis - CLL - Hodgkin's in MOPP - Cushing - like syndrome
1. Taken daily 2. No protection against STDs 3. Raises triglycerides 4. Depression - weight gain - nausea - HTN 5. Hypercoagulable state
Succinylcholine
Cell membrane Ca2+ channels of cardiac sarcomere

19. How would you treat African Trypanosomiasis (sleeping sickness)?
Suramin
Altered bacterial Dihydropteroate Synthetase - Decreased uptake - or Increased PABA synthesis
proarrhythmic
Forms toxic metabolites in the bacterial cell - Bactericidal

20. What is the mechanism of Azathioprine?
- DNA intercalator - Hodgkin's - myeloma - sarcoma - and solid tumors - Cardiotoxicity & alopecia
Stimulates beta adrenergic receptors
Antimetabolite derivative of 6- mercaptopurine that interferes with the metablolism and synthesis of nucleic acid.
proximal convoluted tubule

21. Name the steps in drug approval(4)?
- Phase I (clinical tests) - Phase II - Phase III - PhaseIV (surveillance)
Decreases synthesis of Mycolic Acid
viral kinase
Blocking muscarinic receptors in the circular fibers of the eye - results in unopposed action of radial muscles to dilate.

22. What is the clinical utility of clonidine?
osmotic diuretic - increase tubular fluid osmolarity - thereby increasing urine flow
Inhibit RT of HIV and prevent the incorporation of viral genome into the host DNA
Treatment of hypertension - especially with renal disease (lowers bp centrally - so flow is maintained to kidney).
- Hydralazine - Procainamide - INH - phenytoin

23. Which cancer drugs effect nuclear DNA (4)?
troponin - tropomyosin system
- Alkalating agents+cisplatin - Doxorubicin+Dactinomycin - Bleomycin - Etoposide
decrease
Diuresis in pateints with sulfa allergy

24. What is Imipenem always administered with?
Cilastatin
alpha -1 > alpha -2; used as a pupil dilator - vasoconstrictor - and for nasal decongestion
- aminoglycosides - loop diuretics - cisplatin
Finasteride inhibits 5 Alpha - reductase - this decreases the conversion of testosterone to dihydrotestosterone - useful in BPH

25. Beta Blockers - BP?
Antifungal.
decrease
No - hemicholinum block the uptake of Choline and thus Ach synthesis
Local anesthetic.

26. Norepi feedbacks and inhibits the presynaptic receptor by What mechanism
Binding to the presynaptic alpha 2 release modulating receptors
Aminoglycosides
1) Aminoglycosides = bactericidal 2) Tetracyclines = bacteriostatic
Ca2+ (Loops Lose calcium)

27. What are Amantadine - associated side effects?
- NaHCO3
Ataxia - Dizziness - Slurred speech
- Alkalinize urine & dialysis
- Aminocaproic acid

28. When is HIV therapy initiated?
Diarrhea - Urination - Miosis - Bronchospasm - Bradycardia - Excitation of skeletal muscle and CNS - Lacrimation - Sweating - and Salivation = DUMBBELS; also abdominal cramping
Inhibits platelet aggregation by irreversibly inhibiting the ADP pathway involved in the binding of fibrinogen.
Similar to cyclosporine; binds to FK- binding protein - inhibiting secretion of IL-2 and other cytokines.
When pts have Low CD4+ (< 500 cells/cubic mm) or a High Viral Load

29. List the mechanism - clinical use - & toxicity of Cisplatin.
- Alkalating agent - testicular - bladder - ovary -& lung - Nephrotoxicity & CN VIII damage.
1. Weight gain 2. Hepatotoxicity (troglitazone)
GI distress - Tooth discoloration and Inhibition of bone growth in children - Fanconi's syndrome - Photosensitivity
SLUD (salivation - Lacrimation - urination - Defecation)as well as airway secretion - GI motility - acid secretions

30. What is Metronidazole combined with for 'triple therapy'? Against What organism?
- Alkalates DNA - CML - Pulmonary fibrosis hyperpigmentation
DHPG (dihydroxy-2- propoxymethyl guanine)
GI discomfort
Bismuth and Amoxicillin or Tetracycline; against Helobacter pylori

31. What is a possible toxicity of Alpha - glucosidase inhibitors used in type -2 diabetes?
GI disturbances.
Norepinephrine (Alpha1 -2 and beta 1)
Edrophonium
- Steroids - Tamoxifen

32. What is the MOA of Amantadine?
Beta - lactam antibiotics
Gram + and Anerobes
Blocks viral penetration/uncoating; may act to buffer the pH of the endosome
penicillinase resistant

33. Which drug(s) cause this reaction: P450 induction(6)?
- Penicillamine
Phase 1 = prolonged depolarization - no antidote - effect potentiated by anticholinesterase; Phase 2 = repolarized but blocked - an anticholinesterase is the antidote for this phase.
- Barbiturates - phenytoin - carbamazipine - rifampin - griseofulvin - quinidine
- Upper respiratory tract infections - pneumonias - STDs: Gram+ cocci (streptococcal infect in pts allergic to penicillin) - Mycoplasma - Legionella - Chlamydia - Neisseria

34. Name two LPL stimulators.
Competitive inibitor of progestins at progesterone receptors.
Beta - lactamase cleavage of Beta - lactam ring
Gemfibrozil - Clofibrate
Norepinephrine

35. How do you treat coma in the ER (4)?
- Alkalates DNA - CML - Pulmonary fibrosis hyperpigmentation
Onchocerciasis ('river blindness'-- rIVER- mectin)
Benzodiazepine.
- Airway - Breathing - Circulation - Dextrose (thiamine & narcan) - ABCD

36. What are the Macrolides used for clinically?
- Upper respiratory tract infections - pneumonias - STDs: Gram+ cocci (streptococcal infect in pts allergic to penicillin) - Mycoplasma - Legionella - Chlamydia - Neisseria
1) Hypersensitivity reactions 2) Increased nephrotoxicity of Aminoglycosides 3) Disulfiram - like reaction with ethanol (those with a methylthiotetrazole group - e.g. - cefamandole)
Staphlococcus aureus
Neurotoxicity - Acute renal tubular necrosis

37. What is the clinical use for Clomiphene?
Treatment of infertility.
- B51Naloxone / naltrexone (Narcan)
Sulfonylureas are oral hypoglycemic agents - they are used to stimulate release of endogenous insulin in NIDDM (type -2).
Saquinavir - Ritonavir - Indinavir - Nelfinavir

38. Ca2+ sensitizers'- site of action?
Heparin catalyzes the activation of antithrombin III.
Chronic gout.
troponin - tropomyosin system
Tendonitis and Tendon rupture

39. Which drug(s) cause this reaction: Agranulocytosis (3)?
Inhibits xanthine oxidase - decresing conversion of xanthine to uric acid.
Pseudomonas species and Gram - rods
- Cloazapine - carbamazapine - colchicine - PTU
Diarrhea

40. List the mechanism - clinical use - & toxicity of Prednisone.

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

41. What process does Zafirlukast interfere with?
- Glucocorticoid withdrawal
Leukotrienes increasing bronchial tone.
Competitive inibitor of progestins at progesterone receptors.
osmotic diuretic - increase tubular fluid osmolarity - thereby increasing urine flow

42. What microorganisms is Aztreonam not effective against?
Giardiasis - Amoebic dysentery (E. histolytica) - Bacterial vaginitis (Gardnerella vaginalis) - Trichomonas
Epinephrine
Gram + and Anerobes
Cestode/tapeworm (e.g. - D. latum - Taenia species Except Cysticercosis

43. How does resistance to Vancomycin occur?
1. Phospholipase A2 is prevented from releasing arachidonic acid 2. Decreases protein synthesis thus lowering amount of Cyclooxygenase enzymes
very short acting
With an amino acid change of D- ala D- ala to D- ala D- lac
ARF - shock - drug overdose - decrease intracranial/intraocular pressure

44. What are the indications for using amphetamine?

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

45. Name three K+ sparing diuretics?
Misoprostol is contraindicated in women of childbearing potential because it is an abortifacient.
Spironolactone - Triamterene - Amiloride (the K+ STAys)
Prevents the release of ACh - Which results in muscle paralysis.
- Alkalating agent - NHL - Breast - ovary - & lung. - Myelosuppression - & hemorrhagic cystitis.

46. Ethacrynic Acid - clinical use?
- Nitrate - hydroxocobalamin thiosulfate
These B-2 agonists cause respiratory smooth muscle to relax.
Diuresis in pateints with sulfa allergy
- Alkalating agent - testicular - bladder - ovary -& lung - Nephrotoxicity & CN VIII damage.

47. What is Nifurtimox administered for?

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

48. What is the mechanism of action and clinical use of the antiandrogens Ketoconazole and Spironolactone?
Inhibits organification and coupling of thyroid hormone synthesis. Also decreases peripheral conversion of T4 to T3.
As PABA antimetabolites that inhibit Dihydropteroate Synthase - Bacteriostatic
decrease
Inhibit steroid synthesis - used in the treatment of polycystic ovarian syndrome to prevent hirsutism.

49. What is the category of drug names ending in - phylline (e.g. Theophylline)
- Methylene blue
TMP- SMZ (DOC) - aerosolized pentamidine
Methylxanthine.
- Vinca alkaloids(inhibit MT) - Paclitaxel

50. Isopoterenol was given to a patient with a developing AV block - why?
Sucralfate cannot work in the presence of antacids or H2 blockers because it requires an acidic environment to polymerize.
- Shifts the curve to the right - increases Km
Milk or Antacids - because divalent cations inhibit Tetracycline absorption in the gut
Stimulates beta adrenergic receptors