Conivaptan-d₄is intended for use as an internal standard for the quantification of conivaptan by GC- or LC-MS. Conivaptan is an antagonist of the arginine vasopressin (AVP) receptors V_1Aand V₂(K_is = 0.48 and 3.04 nM for rat liver V_1Aand kidney V₂, respectively).¹It also competitively inhibits oxytocin binding to rat uterine oxytocin receptors (K_i= 44 nM) but has no effect on AVP binding to anterior pituitary V_1Breceptors at concentrations up to 100 μM in a radioligand binding assay. Conivaptan suppresses AVP-induced increases in intracellular calcium in vascular smooth muscle cells (VSMCs)in vitroand the pressor response in pithed rats. Conivaptan (0.01-0.3 mg/kg, i.v.) increases urine output and decreases urine osmolality in dehydrated conscious rats in a dose-dependent manner. It also reduces brain edema and blood-brain barrier disruption in a mouse experimental stroke model.²

1.Tahara, A., Tomura, Y., Wada, K.-I., et al.Pharmacological profile of YM087, a novel potent nonpeptide vasopressin V1A and V2 receptor antagonist, in vitro and in vivoJ. Pharmacol. Exp. Ther.282(1)301-308(1997) 2.Zeynalov, E., Jones, S.M., Seo, J.W., et al.Arginine-vasopressin receptor blocker conivaptan reduces brain edema and blood-brain barrier disruption after experimental stroke in micePLoS One10(8)e0136121(2015)