Rosuvastatin Calcium (Rosuvastatin hemicalcium) is a competitive HMG-CoA reductase inhibitor with an IC₅₀ of 11 nM^[1]. Rosuvastatin Calcium potently blocks human ether-a-go-go related gene (hERG) current with an IC₅₀ of 195 nM, delayed cardiac repolarization, and thereby prolonged action potential durations (APDs) and corrected QT interval (QTc) intervals^[2]. Rosuvastatin Calcium reduces the expression of the mature hERG and the interaction of heat shock protein 70 (Hsp70) with the hERG protein. Rosuvastatin Calcium is very effective in lowering low-density lipoprotein (LDL) cholesterol, triglycerides, and C-reactive protein levels^[3]. IC50 & Target: IC50: 11 nM (HMG-CoA) and 195 nM (hERG)^[1,2] In Vivo: Rosuvastatin Calcium (10 mg/kg, intraperitoneal) prolonges QTc in conscious and unrestraines guinea pigs from 201 ± 1 to 210 ± 2 ms.