Terlipressin is a peptide drug used in hospitals to treat a severe complication of advanced liver disease. Sold in the U.S. under the brand name Terlivaz, it illustrates a different category of peptide therapeutics than the GLP-1 drugs or growth-hormone peptides more commonly discussed on this site: a decades-old hormone analog repurposed for a narrow, serious, inpatient condition.
What It Is
Terlipressin is a synthetic analog of vasopressin (also called antidiuretic hormone), the body's own peptide hormone that regulates blood vessel tone and water retention. Terlipressin is designed as a prodrug: once in the body, it's gradually converted into lysine-vasopressin, the active form that binds vasopressin receptors, with a particular affinity for the V1 receptor subtype found on blood vessels in the gut and splanchnic circulation.
What It's Approved For
The FDA approved terlipressin (Terlivaz, from Mallinckrodt) in 2022 for adults with hepatorenal syndrome with rapid reduction in kidney function, often referred to as HRS-1. Hepatorenal syndrome is a form of acute kidney failure that occurs in people with advanced, decompensated liver disease, typically cirrhosis with ascites, and it carries a high risk of death without treatment. Terlipressin is administered by injection in a hospital setting; it is not a self-administered outpatient therapy.
How It Works
In advanced liver disease, blood vessels in the splanchnic circulation (the vessels supplying the gut and abdominal organs) become abnormally dilated, which lowers effective blood flow to the kidneys and other organs even though total blood volume may be normal. By activating V1 receptors, terlipressin constricts these dilated splanchnic vessels, which raises systemic blood pressure and improves blood flow back to the kidneys — the mechanism believed to drive its effect on hepatorenal syndrome.
What the Approval Trial Showed
Terlipressin's FDA approval was supported primarily by the CONFIRM trial, a placebo-controlled Phase 3 study of around 300 patients with HRS-1. The trial met its primary endpoint of "verified HRS reversal," a composite measure of kidney function improvement, with a statistically significant difference favoring terlipressin over placebo.
Safety Considerations
Terlipressin carries an FDA boxed warning, the agency's strongest safety label, for serious or fatal respiratory failure. In the CONFIRM trial, respiratory failure was reported in 15.5% of patients on terlipressin compared with 7.1% on placebo, and the risk is higher in patients with volume overload or the most severe grade of acute-on-chronic liver failure. Because of this, prescribing guidance calls for checking oxygen levels before starting treatment, avoiding use in patients who are already hypoxic, and monitoring oxygen saturation continuously during treatment, stopping the drug if it falls too low. Other warnings cover ischemic events (reduced blood flow to tissue, a logical risk from a vasoconstricting drug), potential effects on liver-transplant eligibility, and risk to a developing fetus.
Where It Fits
Terlipressin is a hospital-administered, physician-directed treatment for a specific, severe complication of liver disease — not a drug patients manage on their own, and not related to the peptide drugs marketed for weight loss, muscle building, or anti-aging that this site covers elsewhere. Anyone whose family member or loved one is being treated for hepatorenal syndrome should rely on their hospital's medical team to weigh terlipressin's benefits against its respiratory risk for that specific patient, since the decision depends heavily on individual factors like fluid status and liver disease severity that only a treating physician can assess.
The Bottom Line
Terlipressin shows how an old hormone's chemistry can be repurposed into a targeted modern therapy: four decades after vasopressin's physiology was well understood, a modified, longer-acting version of it became the first FDA-approved drug specifically for hepatorenal syndrome in the United States, arriving well after versions of the drug were already used in other countries.