Conivaptan for the treatment of hyponatremia.
Conivaptan is the first dual vasopressin V1a/V2 receptor antagonist approved by the US FDA for the treatment of euvolemic and hypervolemic hyponatremia in hospitalized patients. Short-term use of intravenous conivaptan has been shown to promote effective free-water duresis and resolution of hyponatremia in several clinical trials. Adverse effects reported with short-term use mostly include infusion site reactions. However, they may also include serious effects including unexpectedly rapid serum Na+ correction, hypokalemia and orthostatic hypotension. Despite its proven efficacy in hospitalized patients, the development of oral conivaptan has been discontinued due to its shared hepatic clearance with many commonly used drugs. Thus, data is lacking on the long-term efficacy of conivaptan in patients with chronic hyponatremia. The decision to use conivaptan in addition to conventional therapy for euvolemic or hypervolemic hyponatremic patients must be carefully considered according to the patient history and response to conventional treatment.