Pimozide Fluoxetine

CypP450 3A3 /4 Antidepressants tricyclics, nefazodone, fluoxetine, fluvoxamine, citalopram, mirtazepine, venlafaxine Antipsychotics chlorpromazine, clozapine, pimozide, quetiapine, risperidone... 

Hypersensitivity to SSRIs in combination with a monoamine oxidase inhibitor (MAOl), or within 14 days of discontinuing an MAOl administration of thioridazine with fluoxetine or within a minimum of 5 weeks after fluoxetine has been discontinued coadministration of fluvoxamine with cisapride, thioridazine or pimozide concomitant use of thioridazine with paroxetine concomitant use of pimozide with sertraline coadministration of sertraline oral concentrate and disulfiram. 

Fraser, A.G. (1997) Pharmacokinetic interactions between alcohol and other drugs. Clin Pharmacokinet 33 79—90. Friedman, E.H. (1994) Re bradycardia and somnolence after adding fluoxetine to pimozide regimen. Can/ Psychiatry 39 634. 

There are several antipsychotics that are substrates to CYP2D6 (von Bahr et ah, 1991 Jerling et ah, 1996 Ring et ah, 1996 (Fang and Gorrod, 1999 Flockhart and Oesterheld, 2000) (Table 26.3). Moreover, several antipsychotics may act as inhibitors of CYP2D6-mediated biotransformation. These include thioridazine, chlorpromazine, haloperidol, fluphenazine, and pimozide (Desta et ah, 1998 Shin et ah, 1999). Of particular salience is the fact that the serotonin selective reuptake inhibitors (SSRIs) fluoxetine and paroxetine are metabolized to a significant extent by this isoenzyme. 

Fenfluramine augmentation of SRIs in one open study benefited six of seven patients (233). Many patients have both Tourette s and OCD symptoms, and one case study found that pimozide helped Tourette s symptoms, whereas fluvoxamine helped the OCD symptoms, suggesting some specificity for each symptom (234). In a naturalistic study of Tourette s with associated OCD, adjunctive fluoxetine produced 81% improvement in the complicating OCD symptoms (235). 

Via CYP450 3A4 inhibition, fluoxetine could theoretically increase the concentrations of pimozide, and cause QTc prolongation and dangerous cardiac arrhythmias... 

Use with CYP450 3A4 inhibitors (e.g., drugs such as fluoxetine, sertraline, fluvoxamine, and nefazodone foods such as grapefruit juice) can raise pimozide levels and increase the risks of dangerous arrhythmias... 

Clinically important, potentially hazardous interactions with amiodarone, azithromycin, bepredil, bosentan, bretylium, cisapride, clarithromycin, disopyramide, erythromycin, erythromycin fluconazole, fluoxetine, fluvoxamine, grapefruit juice, indinavir, itraconazole, ketoconazole, metronidazole, miconazole, nefazodone, nilotinib, paroxetine, pimozide, probucol, procainamide, quinidine, quinine, ritonavir, saquinavir, sertraline, sotalol, SSRIs, terfenadine, troleandomycin, voriconazole, zileuton, ziprasidone... 

Clinically important, potentially hazardous interactions with alprazolam, aprepitant, astemizole, atorvastatin, benzodiazepines, carbamazepine, chlordiazepoxide, cilostazol, clonazepam, clorazepate, colchicine, conivaptan, cyclosporine, dabigatran, dasatinib, diazepam, digoxin, dihydroergotamine, disopyramide, ergot alkaloids, fesoterodine, fluoxetine, flurazepam, fluvastatin, HMG-CoA reductase inhibitors, imatinib, ixabepilone, lapatinib, lopinavir, lorazepam, lovastatin, methylprednisolone, methysergide, midazolam, nilotinib, oxazepam, paroxetine, pimozide, pravastatin, prednisone, quazepam, repaglinide, rimonabant, rivaroxaban, sertraline, silodosin, simvastatin, solifenacin, temazepam, temsirolimus, tolvaptan, trabectedin, triazolam, warfarin, zidovudine... 

Clinically important, potentially hazardous interactions with aprepitant, astemizole, carbamazepine, colchicine, cyclosporine, dihydroergotamine, ergot alkaloids, ergotamine, erythromycin, fluoxetine, fluvoxamine, methylprednisolone, methysergide, oral contraceptives, paroxetine, pimozide, prednisolone, rifampicin, sertraline, solifenacin, terfenadine, warfarin... 

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... 

Simultaneous amitriptyline, clomipramine, desipramine, doxepin, fluoxetine, imipramine, maprotiline, metoclopramide, norfluoxetine, nortriptyline Noninterfering carbamazepine, chlordiazepoxide, clobazam, diazepam, flurazepam, flus-pirilene, haloperidol, lorazepam, nitrazepam, nordiazepam, oxazepam, perazine, pimozide, spiroperidol, trifluperidol Interfering fluvoxamine... 

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