Haloperidol Rifampicin

Blood concentrations of haloperidol are reduced during rifampicin administration, owing to shortening of the half-life of haloperidol (SEDA-12, 258) (60). 

ARIPIPRAZOLE, CLOZAPINE, HALOPERIDOL RIFABUTIN, RIFAMPICIN 1 levels of these antipsychotics t metabolism Watch for poor response to these antipsychotics consider increasing the dose... 

Clinically important, potentially hazardous interactions with amiodarone, astemizole, bepridil, carbamazepine, chloroquine, cisapride, clarithromycin, dihydroergotamine, disopyramide, ergotamine, grapefruit juice, halofantrine, haloperidol, itraconazole, ketoconazole, methadone, moxifloxacin, phenobarbital, phenytoin, pimozide, procainamide, quinidine, rifampicin, ritonavir, sotalol, St John s wort, telithromycin, terfenadine, voriconazole... 

The serum levels of haloperidol can be reduced by rifampicin (rifampin), and possibly raised by isoniazid. 

The trough serum haloperidol levels of 15 schizophrenics fell to 37.4% of the expected level after they took rifampicin 600 mg daily for 7 days. After 28 days the serum level had dropped further to 30% of the expected level. In another group of 5 patients taking haloperidol and rifampicin, the serum haloperidol levels rose to 229% of the previous level 7 days after rifampicin was stopped, and to 329% 28 days after rifampicin was stopped. The clinical effects of the haloperidol appeared to be reduced by the rifampicin. ... 

The likeliest explanation is that the rifampicin, a recognised enzyme inducer, increases the metabolism and loss of the haloperidol from the body. 

The interaction between haloperidol and rifampicin would appear to be established and clinically important. Be alert for any evidence of reduced haloperidol effects if rifampicin alone is used, and possibly increased effects if isoniazid alone is used. Adjust the haloperidol dosage if necessary. 

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