Several references as well as significant clinical experience indicate non-porphyrinogenicity.

(To be edited, initial data ST OCT 04) Opioid analgesic often used in acute porphyric crisis. After conjugation with glucuronic acid to morphine-3-glucuronide it is eliminated by the kidneys. MFM James, RJ Hift. Porphyrias. Br J Anaesth 2000; 85, 143-53: use EPI-list: safe South African list: use French list: use Kalman, Bonkovsky: safe Anderson KE: Effects of antihypertensive drugs on hepatic heme biosynthesis, and evaluation of ferrochelatase inhibitors to simplify testing of drugs for heme pathway induction.Biochem Biophys Acta 543:313, 1978: safe Moore MR, Hift RJ: Drugs in the acute porphyrias. Cell Mol Biol 43:89, 1997: probably safe.

Uneventful use reported in 41 patients with acute porphyria.