Quiz 4

  1. What gene codes for p-glycoprotein?
    ABCB1 (ATP-binding cassette)
  2. What are the aliases for p-glycoprotein?
    • P-gp
    • MDR1
  3. Where can you find p-glycoproteins?
    • intestine
    • liver
    • kidney
    • brain
    • placenta
    • adrenal
    • testes
  4. What are some substrates for p-glycoproteins (could get pumped right back out)?
    • digoxin
    • allegra
    • vincristine
    • indinavir
    • colchicine
    • topotecan
    • paclitaxel
    • loperamide
  5. What are some inhibitors of p-glycoprotein?
    • ritonavir
    • cyclosporine
    • verapamil
    • erythromycin
    • ketoconazole
    • itraconazole
    • quinidine
    • azithromycin
    • valspodar
  6. Why might a patient without heart problems be taking verapamil (calcium channel blocker)?
    b/c verapamil inhibits p-glycoprotein, so by doing that, you are allowing more antineoplastic drug to be absorbed
  7. What are some inducers of p-glycoproteins?
    • rifampin
    • St. John's Wort
  8. Where might you find organic cation transporters?
    • kidney
    • brain
  9. What are some substrates of organic cation transporters (could get pumped out by)?
    • cimetidine
    • methotrexate
    • zidovudine
  10. What are some inhibitors of organic cation transporters?
    • *probenecid
    • cefadroxil
    • cefamandole
    • cefazolin
  11. What are some inducers of organic cation transporters?
    none known yet
  12. What is the benefit of giving probenecid to someone?
    for severe infection, it will block the excretion of antibiotics, so it will allow them to be increased in the body and be more effective
  13. Which antibiotics can block their own elimination?
  14. What are some cardiovascular substrates for p-glycoprotein?
    • mostly calcium channel blockers
    • verapamil (Calan)
    • nicardipine (Cardene)
    • Diltiazem
    • Digoxin for CHF
  15. What are some antineoplastic substrates for p-glycoprotein?
    • vinblastine (Velban)
    • vincristine (Oncovin)
    • etoposide (VePesid)
    • paclitaxel (Taxol)
  16. What are some xenograft transplantation substrates for p-glycoprotein?
    • cyclosporine (Neoral)
    • tacrolimus (Prograf)
  17. What are some steroids used for inflammatory conditions that are substrates for p-glycoprotein?
    • dexamethasone (Decadron)
    • hydrocortisone (Cortef)
  18. Which statins are converted by CYP3A4?
    • SAL
    • simvastatin
    • lovastatin
    • atorvastatin
  19. How do statins work?
    they inhibit HMG-CoA reductase, which forms cholesterol, so you lower cholesterol
  20. Which statin is metabolized by 2C9?
    • fluvastatin
    • "flew to the sea"
  21. Which statin is not metabolized by a CYP?
  22. How is pravastatin metabolized?
    by sulfation and processed by p-glycoprotein
  23. Which statin is metabolized by 2C8 and a little by 3A4?
  24. Name the 7 most notable drugs/foods that interact with the statins.
    • cyclosporine
    • erythromycin
    • azole antifungals
    • gemfibrozil
    • nefazodone
    • verapamil
    • grapefruit juice
  25. Which statins can you give with cyclosporine (Neoral/Sanddimmune)?
    • pravastatin
    • fluvastatin
  26. What enzyme is cyclosporine a substrate for?
  27. Which drug can increase lovastatin levels, cause myopathy and rhabdomyolysis?
  28. Which antibiotic is an inhibitor of 3A4?
  29. Which antibiotics lead to increased statin levels?
    • erythromycin
    • clarithromycin
    • troleandomycin
  30. Which antibiotics are safe to use w/ statins b/c they don't inhibit 3A4?
    • azith
    • dirithromycin
  31. If you want to inhibit 3A4, which azole should you use?
  32. Why can you not use azole antifungals when taking statins?
    they are potent inhibitors of 3A4
  33. Which azole inhibits 2C9?
  34. Which antifungal would you not take if you are taking fluvastatin? (think of metabolism)
    • fluconazole
    • *this inhibits 2C9
  35. Which antihyperlipidemia drug should you not take if you are on statins?
  36. Gemfibrozil
    • Lopid
    • Clofibrate
    • Fenofibrate
  37. Cyclosporine
    • Neoral
    • Sanddimmune
  38. What will happen if you take Gemfibrozil with a statin?
    additive effect = more myopathy and rhabdomyolysis
  39. Nefazodone
  40. What is nefazadone?
    • antidepressant
    • not used much anymore
  41. Name one of the most potent 3A4 inhibitors that is an antidepressant.
  42. Instead of using nefazodone if you are taking a statin, what is a good alternative?
    fluoxetine (prozac)
  43. What 2 statins might be reasonable to take if you are on nefazodone?
    • fluvastatin
    • pravastatin
  44. Why is verapamil bad?
    inhibits 3A4
  45. Why is grapefruit juice bad?
    • has flavinoids that inhibit p-glycoprotein and 3A4 up to 24 hours in the GI tract
    • causes rhabdomyolysis b/c drugs are not cleared
  46. Which two statins does grapefruit juice not affect? Why?
    • fluvastatin (Lescol) ---> 2C9
    • pravastatin (Pravachol) -----> sulfation
  47. Which drug is a racemic mixture of R and S stereoisomers?
  48. Which stereoisomer of warfarin is 5 times more potent?
  49. S warfarin is metabolized by?
  50. R warfarin is metabolized by?
    3A4 and 1A2
  51. Which drugs inhibit the clearance of Swarfarin?
    • bactrim, septra (trimethoprim/sulfamethoxazole)
    • amiodarone (cordarone)
    • metronidazole (flagyl)
  52. Which drugs inhibit the clearance of Rwarfarin?
    • cimetidine (tagamet)
    • omeprazole (prilosec)
    • amiodarone (cordarone)
  53. What is the MOA of warfarin?
    decreases clotting factors by inhibiting gamma carboxylation by vitamin K reductase
  54. What drugs can decrease platelet aggregation and increase bleeding (additive effect to warfarin)?
    • aspirin
    • NSAIDs
    • acetaminophen
    • azole antifungals
    • high doses of penicillin or moxalactam
  55. Which drugs can interact adversely with St. John's Wort?
    • cyclosporine
    • digoxin
    • anti HIV meds (indinavir) (protease inhibitors)
    • anticoagulants
    • SSRIs
    • theophylline
    • oral contraceptives
Card Set
Quiz 4
Drug Interactions