TOLVAPTAN

TOLVAPTAN: Tolvaptan is a medication used to treat a condition called hyponatremia, which is characterized by low levels of sodium in the blood. It is also used for the management of polycystic kidney disease (PKD), a genetic disorder that causes the formation of fluid-filled cysts in the kidneys.

The mechanism of action of Tolvaptan involves blocking the action of a hormone called vasopressin, also known as antidiuretic hormone (ADH). Vasopressin normally acts on the kidneys to reabsorb water, leading to increased water retention and decreased urine production. By inhibiting the action of vasopressin, Tolvaptan promotes diuresis (increased urine production), thus helping to normalize sodium levels in the blood and reduce fluid accumulation in the PKD cysts.

The dose of Tolvaptan varies depending on the condition being treated. In hyponatremia, the recommended starting dose is usually 15 mg taken once daily, which can be increased up to 60 mg based on individual response. For PKD, the starting dose is 45 mg taken once daily and can be increased up to 120 mg.

Common side effects of Tolvaptan include dry mouth, thirst, increased urination, weakness, constipation, and dizziness. These side effects are usually mild to moderate and improve with continued use. However, there are some potentially serious side effects associated with Tolvaptan, such as liver damage, which can manifest as elevated liver enzymes, yellowing of the skin or eyes (jaundice), dark-colored urine, and abdominal pain. Other serious side effects include dehydration, high sodium levels, and rapid correction of hyponatremia, which can cause neurological symptoms such as confusion, seizures, and coma.

It is important to note that Tolvaptan has a black box warning due to the risk of liver injury, including potentially fatal cases. Therefore, close monitoring of liver function is required during treatment. Tolvaptan is also contraindicated in patients with a history of high liver enzyme levels or liver disease.

As always, it is essential to consult a healthcare professional for complete information about the drug, its uses, dosage, and potential side effects.