Risperidone Amitriptyline

Topiramate may affect alcohol, amitriptyline, CNS depressants, lithium, oral contraceptives, digoxin, estrogens, hydantoins, metformin, risperidone, and valproic acid. 

Cyt 2D6 metabolizes haloperidol, risperidone, thioridazine, sertindole, olanzapine and clozapine common substrates - fluoxetine, paroxetine, sertraline, venlafaxine, amitriptyline, clomipramine, desipramine, imipramine, nortriptyline, propranolol, metoprolol, timolol, codeine, encainide, flecanide. Common inhibitors - paroxetine, sertraline, fluoxetine. 

In 62 patients with co-existing psychotic and depressive symptoms, risperidone (mean dose 6.9 mg/day) was compared with a combination of haloperidol 9 mg/day and amitriptyline 180 mg/day (n = 61) in a multicenter, randomized, double-blind study over 6 weeks (69). The results suggested that haloperidol plus amitriptyline was... 

Muller-Siecheneder F, Muller MJ, Hillert A, Szegedi A, Wetzel H, Benkert O. Risperidone versus haloperidol and amitriptyline in the treatment of patients with a combined psychotic and depressive syndrome. J Clin Psychopharmacol 1998 18(2) 111-20. 

CYP2D6 Antidepressants amitriptyline, clomipramine, imipramine, desipramine, nortriptyline, trimipramine, N-desmethyl-clomipramine, fluoxetine, norfluoxetine, paroxetine, venlafaxine, sertraline Neuroleptics chlorpromazine, thioridazine, perphenazine, haloperidol, reduced haloperidol, risperidone, clozapine, sertindole Others codeine, opiate, propranolol, dextromethorphan 4 no activity 25% in Caucasians 0%-10% in others 5 no activity 2%-10% in all groups 10 reduced activity 47%-70% in Asians <5% in others 17 reduced activity 25%-40% in blacks 0% in others 2XN increased activity 19%-29% in Arabs and Ethiopians <5% in others... 

Clinically important, potentially hazardous interactions with amitriptyline, amphetamines, aprepitant, astemizole, clarithromycin, dexibuprofen, dextroamphetamine, diethylpropion, digitalis, digoxin, duloxetine, erythromycin, isocarboxazid, linezolid, MAO inhibitors, mazindol, methamphetamine, molindone, phendimetrazine, phenelzine, phentermine, phenylpropanolamine, pseudoephedrine, risperidone, selegiline, sibutramine, St John s wort, sumatriptan, sympathomimetics, tranylcypromine, trazodone, troleandomycin... 

Amitriptyline -Clomipramine Desipramine Imipramine Paroxetine Antipsychotics Haloperidol Risperidone Thioridazine Codeine... 

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... 

No pharmacokinetic interaction normally occurs between risperidone and amitriptyline or mirtazapine, but extrapyramidal reactions have been reported in one patient taking amitriptyline with risperidone. 

A study in 12 schizophrenic patients found that amitriptyline 50 to 100 mg daily had no effect on the serum levels of risperidone 3 mg twice daily. However, a 26-year-old man taking amitriptyline 25 mg daily developed extrapyramidal reactions alter his dosage of risperidone was increased from 2 to 4 mg daily On another occasion extrapyramidal adverse effects developed after risperidone 2 mg daily was added to treatment with amitriptyline 25 mg and fluoxetine 20 mg daily. Both pharmacokinetic and pharmacodynamic reasons for this reaction have been suggested. The cases illustrate that there is the potential for an adverse interaction between these drugs, which should be borne in mind when prescribing both drugs. 

Sommers DK, Snyman JR, van Wyk M, Blom MW, Huang ML, Levron JC. Lack of effect of amitriptyline on risperidone pharmacokinetics in schizophrenic patients. IntClin Psychopharmacol (1991) 12, 141-5. 

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