Chemically and metabolically similar to chlorpromazine (safe). No indications of CYP-inducing effects. Several references consider it safe to use.

(To be edited, initial data ST OCT 04) High-dose phenothiazine neuroleptic used in psychoses and in treatment of severe pain (central analgesic effect). Strong histamine antagonist. Metabolized by CYP 2D6. No data pointing to CYP-induction. MFM James, RJ Hift. Porphyrias. Br J Anaesth 2000; 85, 143-53: use. (phenothiazines). EPI-list: safe. French list: use. Moore MR, Hift RJ: Drugs in the acute porphyrias. Cell Mol Biol 43:89, 1997: safe. Andersson; patient inquiry: used without illeffects (n=1). Thunell; patient inquiry: tolerated (n=1). See: Kassman T et al. Lens opacities and phorphobili... (PMID:6077783). Weiss O et al Methotrimeprazine in acute porphyria (PMID 7089770).

Uneventful use reported in 6 patients with acute porphyria.