The effects of oral administration of clonazepam, a new benzodiazepine derivative (F. Hoffmann-La Roche), on the central nervous system were compared with those of diazepam and several anticonvulsants in mice and rats. 1) Clonazepam exhibited a moderate inhibitory effect on the locomotor activity observed with open-field situation in mice and no effect in rats, while it inhibited markedly the rearing behavior in both animals, the duration of action being approximately six hours.
Tramadol-HCl was used clinically in the form of a continuous infusion as the analgesic component of a balanced anaesthetic technique. In over 90% of the anaesthetics a further injection of barbiturate and/or supplementary muscle relaxant was necessary because the patients did not tolerate the operative procedure.
Resting end-expiratory position (REEP) of the respiratory system was monitored continuously using spirometric recording in eleven patients during transition from consciousness to thiopental hypnosis and following subsequent administration of succinylcholine. REEP decreased following thiopental and was little affected by subsequent relaxant in most patients. A fall in REEP was observed within 30 s after thiopental, and a lower, stable level of REEP was attained within approximately 15-45 s. Mean volume of gas expelled from the lungs was 189 (SE 32) ml BTPS.
The behavioral effects of 450191-S and its metabolites were investigated in mice, rats, cats and rhesus monkeys, and they were compared with those of related benzodiazepines (BDZ) such as diazepam and nitrazepam. Oral administration of 450191-S consistently caused sedation without excitability in mice and rats, and it was only 1/2 to 1/266 as potent as the BDZ in producing motor incoordination as assessed by traction, rotarod performance and inclined screen tests in mice, induced much less ataxia in cats and monkeys, and inhibited respiration in anesthetized cats.
This study examined the interaction between i.v. administered midazolam and thiopentone on the loss of response to verbal command ("hypnosis") and the loss of response to transcutaneous electrical stimulation of the ulnar nerve ("anaesthesia") in patients presenting for minor elective surgery. Dose-response curves for thiopentone and midazolam individually and in combination were determined using the two end-points in 300 unpremedicated patients.