The role of terlipressin in hepatorenal syndrome

Hepatorenal syndrome (HRS) is a severe complication in patients with endstage liver disease. It consists of functional renal vasoconstriction leading to severe reduction of the glomerular filtration rate. In some patients the renal failure shows a rapidly progressive course, a clinical pattern known as type 1 HRS. In other cases the renal failure is less severe and remains stable for months, a condition known as type 2 HRS. HRS is pathogenically related to disturbances in circulatory function, mainly characterized by marked arterial vasodilation of the splanchnic circulation, triggered by portal hypertension. This vasodilation may result in effective arterial underfilling, with subsequent activation of vasoconstrictor systems including the renin-angiotensin system and the sympathetic nervous system, as well as hypersecretion of arginine vasopressin. These compensatory mechanisms may lead to renal failure due to the increase in intrarenal resistance and hypoperfusion. Although the available data are derived from studies including a limited number of patients mainly affected by type 1 HRS, vasoconstrictor drugs, in particular the vasopressin analog terlipressin, seem to be the most effective approach for the management of HRS. Associated with albumin infusion, these drugs have been shown to lead to reduced mortality and improved renal function in type 1 HRS. This is particularly true in HRS patients awaiting liver transplantation in whom the vasoconstrictor drugs appear to be the ''bridging'' therapy of choice. Finally, their use has been shown to be safe, and side effects usually disappear after dose reduction