The search for an optimal interval between pretreatment dose of d-tubocurarine and succinylcholine

A study was conducted to determine the optimal interval between the administration of d-tubocurarine (dTc) and succinylcholine (SCh) with regard to onset and duration of neuromuscular block and presence of fasciculations and postoperative myalgias. Forty female patients received dTc 3 mg X 70 kg-1 prior to SCh 1.5 mg X kg-1. The interval between drugs was 0, 1, 3, 5, or 7 minutes. Transduced thumb adduction recorded block onset and recovery. Fasciculations were visually detected. Myalgias were assessed on postoperative interview. Pretreatment interval did not affect the onset or recovery of neuromuscular block. Postoperative myalgias were also independent of pretreatment timing. Fasciculations were blocked with 3, 5, or 7 minute intervals, but not with 0 or 1 minute intervals. Therefore, three minutes appear to be the optimal time interval between administration of dTc and SCh since shorter intervals do not inhibit fasciculations and longer intervals do not afford any additional advantages.