RELAXANT ACTION IN MAN OF DIPYRANDIUM CHLORIDE (M&B 9105A). (A STEROID BIS-QUATERNARY AMMONIUM SALT).

SUMMARY In a number of animal species dipyrandium chloride (M B 9105A) was known to be a curare-like relaxant with an effect-time curve similar to that of suxamethonium (Biggs, Davis and Wien, 1964). The drug was tested in eight conscious human volunteers by stimulating the median nerve at the wrist and recording the contraction of the short muscles of the thumb. The drug was found to be 3.5 to 4.5 times as potent as gallamine but recovery from it was very variable—sometimes it was faster than from gallamine, sometimes it was slower, and never as rapid as from suxamethonium. It is suggested that, in anaesthetized patients, recovery from dipyrandium chloride might be more consistent, and perhaps faster on the average than from gallamine, but clinical observations in six patients who received the drug were inadequate to confirm or contradict this hypothesis.