Only metabolised to a minor extent. Unspecific CYP-inhibitor (CYPs 2C9, 11B1, 1A2, 2C19, 2D6, 2E1, 3A4). To be observed: imidazole is an CYP 2E1 inducer! Several references consider it safe or probably safe. Also repeatedly used without porphyric side effects.

Imidazole histamine-receptor antagonist used in ventricular hyperacidity. Slightly (10-15 %) metabolized enzymatically to sulfdioxide. In large parts excreted unchanged in urine. Unspecific CYP-inhibitor which has been used in the treatment of the acute porphyric attack.

Andersson D: Frequently used without porphyric side effects. Andersson C: Patient reports, tolerated (n=2).

Uneventful use reported in 3 patients with acute porphyria.