| R
|
| Drug |
CYP interaction |
Clinical consequences |
| rabeprazole
| 3A4, 2C19 (no significant interactions. Metabolism similar to that of
other PPIs but less dependent on 2C19)
| ? nil.
|
| ranitidine (See also cimetidine)
| 2D6 : inhibits (also 1A2, 3A4)
| ? little clinical significance
|
| rapamycin : See sirolimus
|
| retinol, retinoic acid {even cholecalciferol}
| inhibit 1A1, 2C8, 2C19
[Xenobiotica 1999 Mar;29(3):231-41]
| ?
|
| CYP26 : METABOLISM (and induction) [J Biol Chem 2000 Mar 10;275(10):6908-14]
| ?
|
| 1A2, 3A4 : convert retinol to retinal (rate-limiting, in liver)
| ?
|
| 1A1, 1B1 : extrahepatic conversion of retinol to retinal [Drug Metab Dispos 2000 Mar;28(3):315-22]
| ?
|
| 1A1, 1A2, 1B1 and 3A4 convert retinal to retinoic acid
[Drug Metab Dispos 2000 Mar;28(3):292-7]
| ?
|
| 2C8 : 4-hydroxylates all-trans retinoic acid [Biochem Pharmacol 1999 Oct 1;58(7):1201-8]
| ?
|
| rifabutin
| CYP3A4 : induces
| Similar to rifampicin
|
| rifampicin (rifampin)
| CYP3A4 : INDUCES
(and metabolism)
| increases eg quinidine clearance
also well documented interactions with warfarin, oral contraceptives,
cyclosporine, glucocorticoids, ketoconazole, theophylline,
digitoxin, and verapamil [Arch Intern Med 1997 Nov 24;157(21):2453-8]
as well as protease inhibitors, zidovudine, delavirdine, itraconazole,
nifedipine, midazolam, triazolam, nortriptyline, doxycycline.
|
| CYP1A2 : INDUCES
| ?
|
| CYP2C8 : INDUCES
| ?
|
| CYP2C9 : INDUCES
| less warfarin effect
|
| CYP2E1 : metabolism
| ?
|
| 2C19 : INDUCES !
| ?
|
| riluzole
| CYP1A2
| ?
|
| risperidone (antipsychotic)
| 2D6 : metabolism
| ?
|
| ritonavir (See also Protease Inhibitors
| CYP2C9 : INHIBITS
| ?
|
| CYP2C19 : INHIBITS
| ?
|
| 2D6 : INHIBITS (Ki 4.8 µmol)
| ?
|
| 3A4 : INHIBITS (Ki 0.14)
| Lower elimination of other HIV PIs, clarithromycin,
ketoconazole, rifabutin
|
| 3A4 : metabolism
| minimal effect of other agents (rifampicin, ketoconazole)!
[Clin Pharmacokinet 1998 Oct;35(4):275-91]
|
| 2D6 : metabolism
| ?
|
| rokitamycin
| 'practically NO CYP3A inhibition' [J Pharm Pharmacol 1999 Oct;51(10):1167-74]
although Zhao et al report a Ki of 5.8 µM [Drug Metab Dispos 1999 Jul;27(7):776-85]
| 'nil' ?
|
| ropinirole (anti-parkinsonian)
| CYP1A2 : metabolism
| no interaction with theophylline
|
| ropivacaine
| CYP1A2 : metabolism
| ?
|
| CYP3A4 : metabolism
| ?
|
| rosiglitazone
| 2C9 : substrate
| ?
|