Vasopressin: Uses, Mechanism, and Side Effects

Key takeaways

• Vasopressin is approved to raise blood pressure in adults with vasodilatory shock that persists despite fluids and catecholamines.
• It works by constricting blood vessels through V1 receptor activation and by promoting water retention through V2 receptors.
• More than 798 trials registered with the compound reflect its wide research use across circulatory and other conditions.
• FAERS reports are dominated by drug ineffectiveness, hypotension, and complications tied to the severe illnesses it is used to treat.
• The approved label does not carry a boxed warning.

What Vasopressin Is

Vasopressin is a hormone-based medication marketed under the brand name Vasopressin. It acts on V1 receptors in vascular smooth muscle, triggering a signaling pathway that releases intracellular calcium and causes blood vessels to narrow. It also acts on V2 receptors, which are linked to the body's water-conserving (antidiuretic) response. Together, these actions explain its use in raising blood pressure while also affecting fluid balance.

What Vasopressin Is Approved For

Vasopressin injection is indicated to increase blood pressure in adults with vasodilatory shock who remain hypotensive despite fluid resuscitation and catecholamine therapy. This is its sole approved indication. The label does not carry a boxed warning.

What the Evidence Shows

Vasopressin has been studied in a large body of clinical research, with 798 registered trials spanning many clinical contexts beyond its approved use. Among the sampled trials, a completed Phase 2/3 study examined dietary approaches to autosomal dominant polycystic kidney disease, while other completed trials explored related vasopressin-pathway agents such as terlipressin for conditions including circulatory dysfunction in cirrhosis and bleeding control during surgery. These examples illustrate the breadth of research interest surrounding vasopressin and related compounds, though they do not all reflect its approved shock indication.

Reported Side Effects

Reports submitted to the FDA's adverse event system most frequently describe the drug being ineffective, along with off label use, which together make up a large share of reports. Hypotension is also commonly reported, alongside complications such as cardiogenic shock, multiple organ dysfunction syndrome, sepsis, condition aggravated, and toxicity to various agents. Because vasopressin is typically used in critically ill patients, many of these reports likely reflect the severity of underlying illness rather than effects caused directly by the drug. These figures represent counts of submitted reports, not confirmed incidence or proof of causation.