O-Desmethylcarvedilol (Desmethylcarvedilol) is an active metabolite of Carvedilol, a non-selective β-adrenergic receptor (β-AR) antagonist. This compound inhibits store overload-induced calcium release in HEK293 cells expressing the RyR2 R4496C mutation (IC50= 7.62 µM). Additionally, O-Desmethylcarvedilol slows the increase in heart rate and prevents diastolic pressure reduction induced by Isoproterenol in conscious rabbits (ED50s = 32 and 5 µg/kg).