Rifampicin Clozapine

Rifampicin can reduce plasma concentrations of clozapine and exacerbate psychotic symptoms (306). 

Joos AA, Frank UG, Kaschka WP. Pharmacokinetic interaction of clozapine and rifampicin in a forensic patient with an atypical mycobacterial infection. J Clin Psychopharmacol 1998 18(l) 83-5. 

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

Arachidonic acid, benzo[a]pyrene, carbamazepine, clozapine, cyclophosphamide, S) and (R)-ibuprofen, omeprazole, paclitaxel, progesterone, retinoic acid, sulfadiazine, temazepam, testosterone, tienilic acid, trimethoprim, (J2)-warfarin, zidovudine Sulfafenazole Rifampicin... 

The serum clozapine levels of a patient were greatly reduced when rifampicin was also given. 

This appears to be an isolated case but it is consistent with the way rifampicin interacts with other drugs. Clozapine serum levels should be well monitored if rifampicin is added, being alert for the need to increase its dosage. An alternative (as in this case) is to use another antibacterial. However, note that there are reports of an interaction between clozapine and ciprofloxacin , (p.749). 

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