Diazepam Neuromuscular blockers

General anesthetics are rarely given alone. In addition to the analgesic agents just mentioned, benzodiazepines (midazolam, Versed diazepam, Valium ) are commonly used as adjuncts for the relief of anxiety, amnesia, and sedation prior to induction of anesthesia. Neuromuscular blockers (e.g., succinylcholine or pancuronium) can also be administered during the induction of anesthesia to relax skeletal muscles. 

A comparative study of 10 patients given gallamine and 4 others given gallamine with intravenous diazepam 150 to 200 micrograms/kg found that the diazepam prolonged the duration of activity of the blocker by a factor of three, and doubled the depression of the twitch response. Persistent muscle weakness and respiratory depression was seen in 2 other patients given tubocurarine after premedication with diazepam. A small reduction (approximately 10%) in neuromuscular blocker requirement has been described with diazepam and tubocurarine or suxamethonium (succinylcholine), but see also (b) below. ... 

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