Non-CYP dependent metabolism. Two references consider it (probably) safe. Reports of safe use. Porphyrinogenic in rat model.

Dibenzene sulfonate salt of a bisquarternary polycyclic ammonium compound. Used for muscle relaxation in anaesthesia. Metabolized non-enzymatically by Hofmann elimination and by ester hydrolysis via unspecific plasma esterases. South African list: use with care. French list: authorized Tanaka and Okimura PMID 7616668: safe Schmidt et al PMID 1751652: safe. Lin and Chen PMID 2400124: safe.