What is the difference between Jynarque (tolvaptan) and Samsca (tolvaptan)?

Jynarque and Samsca both contain tolvaptan. Jynarque is used to slow kidney function decline in adults at risk of developing polycystic kidney disease. Samsca is used to help increase sodium levels in patients with heart failure, and some hormone imbalances.

Jynarque, from Otsuka Pharmaceuticals, is used to slow kidney function decline in adults at risk of rapidly progressing autosomal dominant polycystic kidney disease (ADPKD). ADPKD is a genetic disease in which fluid-filled cysts develop in the kidneys over time and may lead to dialysis or kidney transplantation.

Jynarque is available in 15 mg, 30 mg, 45 mg, 60 mg and 90 mg oral tablets; the dose is given twice a day. Due to the possible side effect of liver failure, Jynarque is available only through a restricted distribution program called the Jynarque REMS. Jynarque was FDA approved in April of 2018.

Samsca, also from Otsuka Pharmaceuticals, is used in adults to help increase sodium (salt) levels in the body, for medical conditions such as heart failure, and some hormone imbalances, like Syndrome of Inappropriate Antidiuretic Hormone (SIADH). Hyponatremia is a condition in which there is an excess of body water relative to body sodium. Samsca helps raise sodium levels in your blood by removing extra body water as urine. Complications of severe hyponatremia may include seizures, hallucinations, psychosis, or coma.

Samsca is available in 15 mg and 30 mg oral tablets; the dose is given once a day. Samsca can also lead to severe liver injury, and Samsca should not be taken for more than 30 days. However, Samsca use is not restricted by a distribution program or REMS, unless it is used to treat ADPKD. Samsca was approved by the FDA in 2009.