Current place of vasopressin analogues in the treatment of septic shock.

Arginine vasopressin and terlipressin increase mean arterial pressure and reduce catecholamine requirements in septic shock patients. Infusing either agent may reduce incidence of new-onset tachyarrhythmias and improve renal function. The recent Vasopressin and Septic Shock Trial did not demonstrate an overall survival benefit of arginine vasopressin infusion (0.03 U/min) compared with norepinephrine (15 microg/min). However, patients with less severe septic shock (ie, < 15 microg/min of norepinephrine) at arginine vasopressin initiation had a lower 28-day mortality rate compared with norepinephrine-only infusion (26.5% vs 35.7%; P = 0.05). An unpublished study comparing terlipressin (1.3 microg/kg/h), arginine vasopressin (0.03 U/min), and norepinephrine (15 microg/min) as first-line vasopressors showed that terlipressin had higher efficacy than arginine vasopressin in reducing catecholamine requirements. Current literature suggests that early infusion of low-dose continuous arginine vasopressin or terlipressin appears superior to a last-resort treatment. However, because no large clinical trials have proven terlipressin's safety in patients with septic shock, arginine vasopressin is preferred until more data are available.