The effect of nefazodone on clozapine plasma concentrations.
The cytochrome enzyme p4503A4 (CYP3A4) is thought to play a major part in the human metabolism of clozapine. Nefazodone is a potent and specific in-vivo inhibitor of CYP3A4. We co-administered nefazodone and clozapine in six patients and found that mean clozapine levels rose by 4% of baseline and norclozapine levels by 16%. Based on these observations, it is inferred that inhibition of CYP3A4 in vivo has minimal effects on clozapine metabolism. Nefazodone appears to be safe when co-administered with clozapine.
Taylor
D
D
Pharmacy Department, Maudsley Hospital, London, UK.
Bodani
M
M
Hubbeling
A
A
Murray
R
R
D000328:Adult; D018687:Antidepressive Agents, Second-Generation / Q000097:blood / Q000494:pharmacology*; D014150:Antipsychotic Agents / Q000097:blood*; D003024:Clozapine / Q000097:blood*; D004347:Drug Interactions; D005260:Female; D006801:Humans; D008297:Male; D010879:Piperazines; D014230:Triazoles / Q000097:blood / Q000494:pharmacology*
D018687:Antidepressive Agents, Second-Generation; D014150:Antipsychotic Agents; D010879:Piperazines; D014230:Triazoles; C051752:nefazodone; D003024:Clozapine