Cytochrome P450 : Alphabetical drug list
Quick Links:
1A2 2C9 2C19 2D6 2E1 3A4
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Drug CYP interaction Clinical consequences
olanzapine : does NOT inhibit 1A2 [Pharmacotherapy 1998 Nov-Dec;18(6):1237-48] or indeed other CYPs. 1A2 : some metabolism
(minor = 2D6)
Potential for interaction with 1A2 inhibitors (fluvoxamine), and inducers (smoking,
? carbamazepine).
omeprazole (proton pump inhibitor) 'few significant interactions' CYP2C19 : metabolism
(? also 2C8, 2C18)
benefit of low activity : increased peptic ulcer cure!
CYP1A2 ? INDUCES (inhibition of 1A2 activity also occurs, but is clinically irrelevant)
2C19 : INHIBITS (IC50 ~ 3 to 10 µmol) potential for interactions e.g. with diazepam(?).
ondansetron CYP1A2 (substrate), even 1A1 ?
2D6 : metabolism ?
3A4 : METABOLISM rifampicin lowers ondansetron area under concentration curve by 50 to 60%
2E1 : metabolism ?
Opioids - SEE ALSO INDIVIDUAL AGENTS. CYP3A4 : hi activity less effective
CYP3A4 : low activity delayed clearance
oral contraceptives (see also components) CYP3A4 : hi activity ineffective
orphenadrine 2B6 : INHIBITS (NOT selective: [Drug Metab Dispos 1997 Mar;25(3):390-3] ) interaction with eg tricyclic antidepressants
2D6 : inhibits ?
2C9 : (inhibits) ?
oestradiol : See estradiol
oxcarbazepine (anticonvulsant) 3A4 : INDUCED significant interaction with eg oral contraceptives
oxycodone 2D6 : activated to oxymorphone blocking 2D6 blocks activation.

Quick Links:
1A2 2C9 2C19 2D6 2E1 3A4

Page author: jo@anaesthetist.com Last update: 2000-6-22