A Study to Evaluate Efficacy and Safety of Extended-Release Niacin + Laropiprant + Simvastatin in Participants With Primary Hypercholesterolemia or Mixed Dyslipidemia (MK-0524B-118)

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/40 mg is equivalent to ERN/LRPT 2 g co-administered with simvastatin 40 mg in reducing low-density lipoprotein cholesterol (LDL-C).