HMGCR and hyperlipidemia: Simvastatin, fluvastatin, lovastatin, and atorvastatin (cluster C1, ATC codes A10BH51/C10AA01/C10BX04/C10BA02/C10BX01/C10BA04, C10AA04, C10AA02/C10BA01, and C10BX15/C10AA05/C10BX03/C10BA05/C10BX11/C10BX08/C10BX06/C10BX12) are HMG-CoA reductase inhibitors (also called statins) that lower serum lipid levels, reducing the risk of cardiovascular events caused by hyperlipidemia; they are in the level 1 ATC C–Cardiovascular system class.