Another drug that reduces intracellular cAMP is the vasopressin 2 receptor (V2R) antagonist tolvaptan, which decreases the progression of ADPKD, suppresses the decline in renal function [3, 19, 20], and has the potential to prolong the time before ESKD onset [21]. This evidence concerns the gene AVPR2 and autosomal dominant polycystic kidney disease.