NIACR1 x HMG-CoA reductase x PGD2 receptor x HCAR3

This study is being done to find out if tablets containing extended release (ER) niacin, laropiprant, and simvastatin (ERN/LRPT/SIM) are as effective as tablets containing ER niacin and laropiprant taken with simvastatin tablets (ERN/LRPT + SIM) for lowering high cholesterol and high lipid levels in the blood. The primary hypothesis is that ERN/LRPT/SIM 2 g /20 mg is equivalent to ERN/LRPT 2 g coadministered with simvastatin 20 mg in reducing low-density lipoprotein cholestrol (LDL-C).