Cytochrome P450 : Alphabetical drug list
Quick Links:
1A2 2C9 2C19 2D6 2E1 3A4
Have you read our disclaimer?
Drug CYP interaction Clinical consequences
aceclofenac 2C9 : METABOLISM ?
acetaminophen : see paracetamol
alfentanil CYP3A4 : metabolism eg. fluconazole inhibits clearance 55% [Anesth Analg 1998 Jul;87(1):190-4] See also [Anesthesiology 1997 Jul;87(1):36-50] - rifampicin and troleandromycin strongly inhibit metabolism.
alprazolam (See also Benzodiazepines) CYP3A4 : metabolism ? expect interactions eg. ritonavir, nefazodone, some SSRIs, itraconazole, troleandromycin
excessive sedation with 3A4 inhibitors
alprenolol (see also beta blockers) 2D6 : metabolism potential for impaired effect / toxicity (2D6 overactivity / lack)
aminoglutethimide CYP11, CYP19, CYP21 : inhibits potent 'adrenal suppression'.
aminophyllin (see theophylline)
amiodarone CYP2C9 : INHIBITS 'clinically significant'; IC50 25µmol Interaction with warfarin may be 2 months later! [Clin Pharmacokinet 1996 Jun;30(6):416-44]
1A2: inhibits (weakly) ?
2D6: INHIBITS increased flecainide levels
3A4 : INHIBITS lignocaine clearance inhibited, cyclosporine toxicity
3A4 : metabolism ?
amitriptyline : See also tricyclics 1A2 : metabolism ?
2C19 : metabolism (most important) SSRIs increase levels!
3A4 : metabolism (next most important) [J Clin Pharmacol 1998 Feb;38(2):112-21] ?
2C9 : metabolism ?
2D6 : metabolism {? also inhibits}
amlodipine 3A4 : inhibits (? metabolism) ? 'minor effect' on cyclosporine [Clin Nephrol 1997 Nov;48(5):336; Hypertension 1994 Sep;24(3):297-300]
1A1 : inhibits ?
2B6 : inhibits ?
amphetamine incl. methylenedioxymetamphetamine = MDMA = 'ecstasy'; methamphetamine is probably similar 2D6 : metabolism serious reaction with HIV protease inhibitors [Arch Intern Med 1999 Oct 11;159(18):2221-4]
amprenavir 3A4 : metabolism interaction with 3A4 inhibitors eg ritonavir
3A4 : INHIBITS (Ki 0.5µM) probably significant
anastrozole CYP19,
also may inhibit 1A2, 2C8, 2C9, 3A4
Angiotensin II receptor blockers : See losartan, valsartan, irbesartan 2C9
Antidepressants : See individual agents. Metabolism varies and is complex, but in general: CYP2D6 : low activity toxicity
CYP2D6: hi activity ineffective
Antihistamines (non-sedating, some) terfenadine, & especially astemizole [see Br J Clin Pharmacol 1999 Mar;47(3):307-13 ]
fexofenadine appears 'safe', as do cetirizine, azelastine, loratadine;[Clin Ther 1999 Feb;21(2):281-95], mizolastine [Clin Exp Allergy 1999 Mar;29 Suppl 1:15-24] (? not ebastine: experimentally prolongs QT)
CYP3A4 : low activity fatal arrhythmias
Antipsychotics (see also individual drugs)
2D6 inhibition : perphenazine > thioridazine > chlorpromazine > haloperidol > fluphenazine > > risperidone > clozapine > cis-thiothixine.
aprindine (class I antiarrhythmic) 1A2 : mild inhibition ?
2D6 : metabolism and INHIBITION significant inhibition [Br J Clin Pharmacol 1993 Apr;35(4):426-30]
artemisinin CYP2B6 : metabolism (main) ?
3A4 : metabolism (minor) (? interaction with azole antifungals, calcium channel blockers)
CYP2C19 : INDUCES probably clinically relevant
astemizole CYP3A4 : METABOLISM low activity = fatal arrhythmias with eg. ketoconazole, erythromycin, cimetidine {Blocks IKr}
3A4 : inhibits (IC50 21 µM) ?
atorvastatin (See also HMG Co-A reductase inhibitors) 3A4 : metabolism interaction with eg troglitazone
azelastine (anti-histamine)
(main metabolite: desmethylazelastine)
CYP2D6 : metabolism ?
CYP3A4 : metabolism ? (azelastine appears NOT to induce arrhythmias)
2D6 : inhibits (Ki 1.2 µM) ?
Azole antifungals CYP2C9 INHIBIT

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

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