Low dose chlormethiazole infusion as a supplement to central neural blockade: blood concentrations and clinical...

Chlormethiazole ethanedisulphonate (Hemineurin) was administered to provide light sedation in patients undergoing surgery with neural blockade. A two stage intravenous infusion system was used and consisted of a loading dose 1520 mg over 30 minutes followed by a maintenance rate of 10 mg/min for the desired period. Patients were sedated smoothly and reliably but could be roused by verbal contact. Recovery from effects was rapid and this is a result of a high clearance of chlormethiazole from the body (approximately 2 l/min). Blood concentrations of chlormethiazole (base, mean +/- SD) associated with light sedation were 5.5 +/- 3.0 mg/l, while a sleep-like state was achieved with concentrations of 6.7 +/- 3.0 mg/l. Given by controlled intravenous infusion under close supervision, chlormethiazole appears close to being an ideal sedative to supplement neural blockade techniques.