| F
|
| Drug |
CYP interaction |
Clinical consequences |
| famciclovir
| NOT metabolised by CYP
| safe with eg cyclosporine [Drug Metab Dispos 1993 Jan-Feb;21(1):18-23]
|
| felbamate (no significant interaction with
lamotrigine, clonazepam, vigabatrin. {may inhibit beta oxidation of valproate}
| 2E1 : METABOLISM
| interaction potential
|
| 3A4 : metabolism (normally minor)
| 3A4 inducers lower levels
|
| 3A4 : induces (!)
| lowers levels of carbamazepine, gestodene
|
| 2C19 : inhibits
| lowers phenytoin clearance
|
| famotidine
| does NOT interact with CYP
| -
|
| felodipine (Ca channel blocker)
| CYP3A4 : metabolism
{inhibition of 3A4 is probably clinically insignificant}
| interaction with 3A4 inhibitors (eg grapefruit juice,
erythromycin ), inducers;
|
| fenfluramine : ? as for dexfenfluramine
|
| fenofibrate (see fibrates)
| 3A4
| potential for interaction with e.g. 3A4 inhibitors
|
| fentanyl
| CYP2D6 : metabolism
| ?
|
| CYP3A4 : METABOLISM (to norfentanyl)
| NO significant interaction with paracetamol or itraconazole
;
ritonavir inhibits its metabolism;
fentanyl competitively inhibits midazolam
metabolism!
|
| fexofenadine (nonsedating antihistamine, cf loratadine)
| 3A4 : METABOLISM
| significant interaction with inhibitors eg.
troglitazone
although fexofenadine "doesn't have cardiac effects"
|
| "Fibrates" (fibric acid derivatives)
(gemfibrozil, fenofibrate, bezafibrate, ciprofibrate)
| 3A4 : METABOLISM
| potential for interaction with 'statins',
warfarin, cyclosporin and oral hypoglycaemic agents
(metformin, tolbutamide, glibenclamide..)
|
| finasteride
| 3A4 : substrate
| ?
|
| flecainide
| CYP2D6 : metabolism
| ? significant effect of 2D6 polymorphism see [Clin Pharmacol Ther 1994 Mar;55(3):256-69]
|
| 2D6 : INHIBITION (IC50 0.44 µmol)
| ?
|
| 1A2 : mild inhibition
| ?
|
| 2C9 : INHIBITION (IC50 = 49 µmol)
| ?
|
| fluconazole
See alsoazole antifungals
| 2C9 : INHIBITS (potent)
| 'clinically significant' - phenytoin, warfarin, sulphamethoxazole,
losartan [Clin Pharmacokinet 2000 Feb;38(2):111-80]
|
| 3A4 : INHIBITS
| potential for significant interactions eg carbamazepine
|
| 2C19 : INHIBITS
| Of uncertain relevance!
|
| fluorouracil (5-fluorouracil, 5FU, 5-FU)
| 2C9 : ? INHIBITS
| warfarin toxicity [Chemotherapy 1999 Sep-Oct;45(5):392-5]
|
fluoxetine (See also SSRIs)
metabolised to norfluoxetine
| CYP2C9 : metabolism
| ?
|
| CYP2C19 : INHIBITS
| ?
|
| CYP2D6 : metabolism
| : interaction potential
|
| 2D6 : INHIBITS (potent)
| many interactions e.g.
may increase perphenazine, haloperidol, thioridazine and risperidone,
metoprolol
levels
|
| 3A4 : inhibits
| ? interaction with alprazolam, midazolam, carbamazepine
parkinsonism reported due to toxicity when given with
cimetidine [J Geriatr Psychiatry Neurol 1995 Oct;8(4):231-3]!
|
| fluphenazine
| 2D6 : metabolism and inhibition (Ki 9.4µM)
| ?
|
| flurbiprofen (NSAID)
| 2C9 : metabolism (alone)
| interaction potential
|
| flutamide (androgen receptor antagonist)
| 3A4 - metabolism
| ?
|
| 1A2 : METABOLISM [Drug Metab Dispos 1997 Nov;25(11):1298-303]
| Interation with imipramine, caffeine, estradiol; the metabolite
2-hydroxyflutamide inhibits 1A2! Also, metabolites may be hepatotoxic.
|
| fluvastatin (See also HMG Co-A reductase inhibitors)
| 2C9 : INHIBITS,
Ki 0.3 to 0.5 µM
| interaction potential
|
| 2C9: METABOLISM (the main route)
| ?
|
| fluvoxamine
{inhibition: 1A2 > 2C19 > 2D6 > 1A1 }
| CYP2C19 : INHIBITS (Ki 0.7 - 4.7 µmol)
| potential interaction with imipramine, clomipramine, amitriptyline,
diazepam, proguanil (high levels) [Eur J Clin Pharmacol 1998 Nov-Dec;54(9-10):735-40]
|
| CYP1A2 : minor substrate
| ?
|
| 1A2 : INHIBITS (0.2µmol)
| ? interaction potential
|
| 2D6 : metabolism (? mild inhibition - Xu says 'no' [Br J Clin Pharmacol 1996 Oct;42(4):518-21])
| ?
|
| 3A4 : INHIBITS
| raised methadone concentrations, interaction with cyclosporine
|