Vasopressin receptor antagonist

Vasopressin receptor antagonists (VRAs) are a group of pharmaceutical drugs that are used to treat various medical conditions such as hyponatremia, heart failure, and polycystic kidney disease. They work by blocking the action of vasopressin, a hormone that regulates the body's water balance.

Mechanism of action

VRAs work by blocking the vasopressin receptor, which is found in the kidney and other parts of the body. Vasopressin, also known as antidiuretic hormone (ADH), binds to these receptors and triggers a series of reactions that help the body retain water. By blocking these receptors, VRAs prevent vasopressin from acting, leading to increased water excretion and decreased water retention.

Types of VRAs

There are three types of vasopressin receptors: V1a, V1b, and V2. Different VRAs target different receptors:

• V1a receptor antagonists are used to treat conditions such as vasodilatory shock and bleeding esophageal varices.
• V1b receptor antagonists are being investigated for potential use in treating depression and anxiety.
• V2 receptor antagonists are used to treat hyponatremia and heart failure.

Examples of VRAs

Some examples of VRAs include:

• Conivaptan is a dual V1a and V2 receptor antagonist used to treat hyponatremia.
• Tolvaptan is a V2 receptor antagonist used to treat hyponatremia and polycystic kidney disease.
• Lixivaptan is a V2 receptor antagonist that is currently under investigation for the treatment of hyponatremia.

Side effects

Like all drugs, VRAs can have side effects. These can include dry mouth, thirst, nausea, abdominal pain, and electrolyte imbalance. It is important for patients to discuss these potential side effects with their healthcare provider before starting treatment with a VRA.

See also

• Vasopressin
• Hyponatremia
• Heart failure
• Polycystic kidney disease