Phosphonic acid derivative, not metabolised. Probably devoid of CYP affinity.

(To be edited, initial data ST OCT 04) Phosphonic acid derivative broad spectrum antibiotic used in urinary tract infections. Most of the dose is eliminated unchanged in urine. No data pointing to CYP interaction. South African list: no data/avoid. French list: use.

Uneventful use reported in 3 patients with acute porphyria.