| H
|
| Drug |
CYP interaction |
Clinical consequences |
| halofantrine
| 2D6 : INHIBITS
| ?
|
| 3A4, 3A5 : METABOLISM
| cardiotoxicity with e.g. ketoconazole, diltiazem, erythromycin,
nifedipine, cyclosporine.
|
| haloperidol (See also Antipsychotics)
{main metabolism is via 3A4}
| CYP3A4 : hi activity
| ? less effective eg. with carbamazepine, rifampicin, phenytoin,
phenobarbital [Clin Pharmacokinet 1999 Dec;37(6):435-56]
|
| CYP3A4 : low activity
| delayed clearance
|
| CYP1A2 metabolism : low activity
| ?
|
| CYP2D6 : metabolism
| ?
|
| 2D6: inhibits
| e.g. inhibition of codeine effect
|
| halothane
| 2E1 : metabolism
| ?
|
| 2A6 : oxidation (!) [Eur J Clin Pharmacol 2000 Feb-Mar;55(11-12):853-9]
|
The metabolites result in rare but life-threatening cases of hepatitis.
|
| anaerobically, halothane is metabolised by 2A6, 3A4 (reduction)!
[Drug Metab Dispos 1996 Sep;24(9):976-83].
| Lipid peroxidation may result, of uncertain clinical significance.
|
| hexobarbital (See also Barbiturates)
| 2C19 : substrate
| ?
|
| HIV protease inhibitors : see Protease inhibitors
|
HMG Co-A reductase inhibitors ('statins')
simvastatin & lovastatin;
also atorvastatin, cerivastatin, fluvastatin;
(pravastatin is NOT metabolised by 3A4)
| 3A4 : substrate
| 3A4 inhibitors raise levels = rhabdomyolysis
eg with cyclosporine A, mibefradil, nefazodone and simvastatin or
lovastatin
phenytoin lowers effect
|
| hydrocodone
| 2D6 : metabolism (to hydromorphone)
| ? significant - See [J Pharmacol Exp Ther 1997 Apr;281(1):103-8]
contrasted with [Clin Pharmacol Ther 1993 Nov;54(5):463-72]
|
| 3A4 : metabolism (?)
| ?
|
| hydrocortisone
| 3A4 : substrate
{with 3A5, 3A7 ?}
| ?
|
| hydroxyzine (1st generation antihistamine)
| 2D6 : inhibits (Ki ~ 4-6 µM)
| ?
|