Opioid. Considered safe in two references. Compare the other phenylpiperidine derivative, pethidine: South African list: use, French list use.

Phenylpiperidine opioid analgesic used in severe pain. Clinical use mainly limited to Scandinavian countries. Metabolized by hydroxylation and demethylation. Anderson KE: Effects of antihypertensive drugs on hepatic heme biosynthesis, .... Biochem Biophys Acta 543:313, 1978: safe. Moore MR, Hift RJ: Drugs in the acute porphyrias. Cell Mol Biol 43:89, 1997: probably safe. Andersson; patient inquiry: used without illeffects (n=1)

Uneventful use reported in 7 patients with acute porphyria.