Human pain thresholds after the application of lypressin, a vasopressin analogue

Recent animal studies indicate that vasopressin has analgetic properties. The aim of this study was to find out if lypressin, a vasopressin analogue, produces analgesia in man. The effect of i.n. lypressin (5 and 10 I.U.) on experimental pain was tested in healthy humans. The lower dose proved high enough to produce a significant antidiuretic effect. Lypressin did not have any marked analgetic effect at these doses either on ischaemic, cutaneous thermal, or dental pain. The results indicate that lypressin cannot be used for pain relief in man at doses low enough not to produce a hazardous water retention.