Beneficial and side effects of arginine vasopressin and terlipressin for septic shock.

Arginine vasopressin (AVP) and its analog, terlipressin (TP), were all demonstrated beneficial for septic shock. What advantages and disadvantages that AVP and TP have for septic shock as well as the mechanism, however, are not completely known. With cecal ligation and puncture-induced septic shock rats and lipopolysaccharide-induced septic shock rabbits, we systematically compared the beneficial and side effects of AVP and TP, in septic shock and the sex difference, and investigated their relationship to Rho kinase and calcium sensitivity. The results indicated that low dose of TP (2.6 μg/kg/h) in combination with norepinephrine (NE) improving vascular reactivity and animal survival were superior to a small dose of AVP (0.03 U/kg/h) in septic shock rats and rabbits. This improving effect of AVP and TP on vascular reactivity was closely related to the activation of Rho-kinase and Rho-kinase-mediating vascular calcium sensitization. A small dose of TP did not result in hyponatremia, did not increase blood bilirubin and decrease platelet count, whereas AVP did. Animal survival and vascular reactivity in female rats after TP or AVP administration were slightly better than male rats, while there were no significant differences. It was suggested that a small dose of TP has better beneficial effect and less side effects on septic shock than AVP. AVP and TP improving vascular reactivity is closely related to Rho-kinase activation and calcium sensitivity improvement. TP or plus NE may be more appropriate for early emergency care for severe septic shock than AVP.