Methadone fluvoxamine

Alderman CP, Frith PA Fluvoxamine-methadone interaction. Aust N Z J Psychiatry 33 99-101, 1999... 

GFJ has been shown to increase the exposure of carbamazepine (175), cisapride (176-179), fluvoxamine (184), losartan (188), methadone (189), scopolamine (191), and sertraline (192). However, only the interaction of GFJ with carbamazepine and cisapride seems to be clinically relevant. No alteration in exposure was observed for clozapine (180,181), heophylline (195), halo-peridol (196), and omeprazole (190). Reports of increased pharmacokinetic parameters of clozapine, theophylline, and haloperidol suggest that an interaction is unlikely to be clinically relevant. Contradicting results were reported for itraconazole (185-187), digoxin (75,183), and sildenafil (193,194). An increased effect on concomitant use of diclofenac and GFJ was observed in rats (182). Overall, the clinical relevance for this drug class appears to be low. 

Other medications that can slow down the metabolism of the liver, thereby causing a person to get a higher dose of methadone than they normally would, include Cimetidine, commonly used for upset stomachs, diazepam, a commonly used anti-anxiety medication, and fluvoxamine, a recently introduced antidepressant medication. Interestingly, alcohol, when used only occasionally, increases methadone levels as compared to decreasing methadone levels when it is used and abused on a chronic basis. 

Interactions are similar to those of opioid analgesics. Methadone has interactions with enzyme inducers. Withdrawal symptoms of methadone are observed upon concurrent administration with phenobarbitone, phenytoin, and rifampicin. Methadone toxicity increases if administered with cimetidine and fluvoxamine. 

Fluvoxamine increases methadone concentrations in patients taking methadone maintenance treatment for the management of opioid dependence (SEDA-19, 11). The addition of sertraline (200 mg/day) produced a modest (16%) increase in methadone concentrations in 31 depressed opioid-dependent subjects after 6 but not 12 weeks of combined treatment (27). The increase in methadone concentrations was more modest than that reported with fluvoxamine, presumably because sertraline is a less potent inhibitor of CYP1A2 and CYP3A4, both of which are involved in methadone metabolism. 

Fluvoxamine increases the effects of methadone, probably by inhibition of methadone metabolism (42). 

Iribarne C, Picart D, Dreano Y, Berthou F. In vitro interactions between fluoxetine or fluvoxamine and methadone or buprenorphine. Fundam Clin Pharmacol 1998 12(2) 194-9. 

Methadone Fluvoxamine Increased effect of methadone Reduced metabolism... 

Methadone Methadone serum levels may rise if fluvoxamine is added, possibly resulting in increased side effects. Sertraline may also increase methadone levels, but no interaction appears to occur with fluoxetine. 

Also analyzed acebutolol, acepromazine, acetaminophen, acetazolamide, acetophenazine, albuterol, amitriptyline, amobarbital, amoxapine, antipsrrine, atenolol, atropine, azata-dine, baclofen, benzocaine, bromocriptine, brompheniramine, brotizolam, bupivacaine, buspirone, butabarbital, butalbital, caffeine, carbamazepine, cetirizine, chlorqyclizine, chlordiazepoxide, chlormezanone, chloroquine, chlorpheniramine, chlorpromazine, chlorpropamide, chlorprothixene, chlorthalidone, chlorzoxazone, cimetidine, cisapride, clomipramine, clonazepam, clonidine, clozapine, cocaine, codeine, colchicine, qyclizine, (yclo-benzaprine, dantrolene, desipramine, diazepam, diclofenac, diflunisal, diltiazem, diphenhydramine, diphenidol, dipheno late, dipyridamole, disopyramide, dobutamine, doxapram, doxepin, droperidol, encainide, ethidium bromide, ethopropazine, fenoprofen, fentanyl, flavoxate, fluoxetine, fluphenazine, flurazepam, flurbiprofen, fluvoxamine, fii-rosemide, glutethimide, glyburide, guaifenesin, haloperidol, homatropine, hydralazine, hydrochlorothiazide, hydrocodone, hydromorphone, hydro g chloroquine, hydroxyzine, ibuprofen, imipramine, indomethacin, ketoconazole, ketoprofen, ketorolac, labetalol, le-vorphanol, lidocaine, loratadine, lorazepam, lovastatin, loxapine, mazindol, mefenamic acid, meperidine, mephenytoin, mepivacaine, mesoridazine, metaproterenol, methadone, methdilazine, methocarbamol, methotrexate, methotrimeprazine, methoxamine, methyl-dopa, methylphenidate, metoclopramide, metolazone, metoprolol, metronidazole, midazolam, moclobemide, morphine, nadolol, nalbuphine, naloxone, naphazoline, naproxen, nifedipine, nizatidine, norepinephrine, nortriptyline, oxazepam, oxycodone, oxymetazo-line, paroxetine, pemoline, pentazocine, pentobarbital, pentoxifylline, perphenazine, pheniramine, phenobarbital, phenol, phenolphthalein, phentolamine, phenylbutazone, phenyltoloxamine, phenytoin, pimozide, pindolol, piroxicam, pramoxine, prazepam, prazosin, probenecid, procainamide, procaine, prochlorperazine, procyclidine, promazine, promethazine, propafenone, propantheline, propiomazine, propofol, propranolol, protriptyline, quazepam, quinidine, quinine, racemethorphan, ranitidine, remoxipride, risperidone, salicylic acid, scopolamine, secobarbital, sertraline, sotalol, spironolactone, sulfinpyrazone, sulindac, temazepam, terbutaline, terfenadine, tetracaine, theophylline, thiethyl-perazine, thiopental, thioridazine, thiothixene, timolol, tocainide, tolbutamide, tolmetin, trazodone, triamterene, triazolam, trifluoperazine, triflupromazine, trimeprazine, trimethoprim, trimipramine, verapamil, warfarin, xylometazoline, yohimbine, zopiclone... 

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