A new soluble acetylsalicylic acid derivative in the treatment of postoperative pain.

In 51 gynaecological patients the effect of an injectable salicylate (lysine acetylsalicylate 1.8 g) on postoperative pain was compared with that of morphine hydrochloride 10 mg. Both drugs were given i.m. No significant difference was found in the speed of action and degree of alleviation of pain. Nausea and vomiting were less frequent in the lysine acetylsalicylate group. This group showed a decrease in capillary blood Pco,, 1 hour after injection, which was significantly greater than that in the morphine group. In the morphine group the decrease in PcOa correlated with a small increase in Po2, but in the lysine acetylsalicylate group this correlation did not exist.