Not metabolised. Considered unsafe in two references.

(To be edited, initial data ST OCT 04) Tablets; dose 30-75 mg/d. Central muscle relaxant, chemically related to GABA, an inhibitory nervous transmittor. Excreted in unchanged form in urine and stool. South African list: use with extreme caution only. French list: interdit

Uneventful use reported in 1 patient with acute porphyria.