Tolvaptan for Autosomal Dominant Polycystic Kidney Disease: Pharmacokinetics and Implications for Practice.

Autosomal dominant polycystic kidney disease (ADPKD) is incurable and occurs once in every 1,000 births. Confirmation of AKPKD is made through imaging and a positive family history. Symptoms typically appear in mid-life and include kidney, side, and/or back pain related to the rupture of kidney cysts, renal stones, infection, pressure of cysts against other organs, and stretching of the renal capsule. In addition to end stage renal disease, cerebral aneurysm may also be a threat to individuals with this diagnosis. Recent clinical trials have shown that tolvaptan, a vasopressin-2 receptor antagonist, produced a moderate to significant reduction in total kidney volume and improved function, leading to its recent approval by the U.S. Federal Drug Administration for treatment of patients with ADPKD. This article provides a comprehensive look at the pathophysiology of ADPKD, pharmacokinetics and pharmacodynamics of tolvaptan, and tolvaptan's clinical implications, effects, and contraindications. In addition, we present a case study discussing tolvaptan's clinical usefulness and address patient concerns in an adult presenting with rapidly progressing ADPKD.