South African medical journal = Suid-Afrikaanse tydskrif vir geneeskunde
-
Etomidate (Hypnomidate; Janssen) 1,25% in sterile water was given rectally on 100 occasions to 50 male Long-Evans rats in doses ranging from 4 mg/kg to 12 mg/kg. The onset and duration of ataxia and hypnosis (i.e. loss of righting ability) were recorded. Ataxia was observed in all rats, even at the lowest dose levels. ⋯ No mortality was recorded despite the rectal administration of ten times the intravenous lethal dose (LD50) for rats. Histological examination of the rectal and colonic mucosa showed that etomidate 1,25% in sterile water (pH 3,5) caused no significant mucosal change, but undiluted etomidate 12,5% (pH 1,8) caused haemorrhagic necrosis. We conclude that rectal etomidate 1,25% in sterile water is an efficient, predictable, evanescent and safe method of inducing anaesthesia in rats and warrants further investigation in clinical anaesthesia in children.