The dose–response curve of CW 1759-50 in rhesus monkeys under isoflurane. The results of nonlinear regression of log dose versus twitch inhibition are shown. Nonlinear regression has been used previously⁵  to analyze the curve for the similar neuromuscular blocking agent CW 002. ED95 and ED50 are shown on the graph in red with SD and CI in boxes; 199 data points are included; P < 0.0001; the n values at the top of the curve show the number of trials producing 100% twitch inhibition at doses indicated. The equation shown is a fifth order polynomial, from which the ED50 and ED95 were extracted.