Extensively metabolised. Substrate of CYP 2D6 and 3A4(major enzymes), 1A2, 2C18, 2C19, 2C9. Inhibitor of CYPs 1A2 and 2D6. No indications of CYP-inducing effects. References state non-porphyrinogenicity.

(To be edited, initial data ST OCT 04) Low-dose phenothiazine neuroleptic with strong antiemetic effect. Extensively metabolized mainly by CYP 2D6. No data pointing to CYP-induction. MFM James, RJ Hift. Porphyrias. Br J Anaesth 2000; 85, 143-53: use (phenothiazines). South African list: use with care Moore MR, Hift RJ: Drugs in the acute porphyrias. Cell Mol Biol 43:89, 1997: safe

Uneventful use reported in 2 patients with acute porphyria.