Terlipressin in hepatorenal syndrome: Evidence for present indications

Hepatorenal syndrome (HRS) is the most frequent life threatening complication of advanced liver failure and cirrhosis. HRS results from a functional renal dysfunction due to circulatory disturbances in patients with advanced liver disease and portal hypertension. Reduction in the effective circulating blood volume and hence hypoperfusion of the kidney is the basic underlying common pathogenetic mechanism for the development of hepatorenal syndrome. The prognosis for HRS remains very poor with types 1 and 2-both having an expected survival time of 2 weeks and 6 months, respectively. 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 HRS. Terlipressin administration significantly increases mean arterial pressure and systemic vascular resistance; while the heart rate, cardiac output, HVPG and portal venous blood flow decrease significantly. This decrease correlates well with the decrease in plasma renin activity. Thus the vasoconstrictor effect of Terlipressin reverses the basic pathology of HRS by reducing the plasma renin activity. The improvement in hemodynamics with Terlipressin is associated with an increase in glomerular filtration rate and deactivation of the vasoconstrictor and sodium-conserving hormones with reduced activity of the RAAS resulting in increased natriuresis. Terlipressin thus reverses HRS and is useful in bridging the patient to liver transplantation and may hence indirectly improve survival. Patients with HRS who show an improvement in renal function with Terlipressin and albumin seem to have an excellent post-transplantation outcome similar to that of patients without HRS. Thus, the use of Terlipressin has been shown to be safe, with minimal side effects that usually disappear after dose reduction, and results in an improved outcome in patients with HRS.