Efficacy and Safety of Extended-Release Niacin/ Laropiprant/Simvastatin Tablets in Participants With Hypercholesterolemia or Mixed Dyslipidemia (MK-0524B-143)

Inclusion criteria: * Has a history of primary hypercholesterolemia or mixed dyslipidemia and meets LDL-C and triglyceride criteria. * Is high risk coronary heart disease (CHD) and has LDL-C ≤190 mg/dL (≤4.91 mmol/L). * Is not high risk CHD and has LDL-C ≤240 mg/dL (≤6.21 mmol/L). Exclusion criteria: * Is pregnant or breast-feeding, or expecting to conceive or donate eggs or sperm during the study. * Has a history of malignancy within ≤5 years, except for adequately treated basal cell or squamous cell skin cancer or in situ cervical cancer. * Consumes more than 3 alcoholic drinks per day (14 per week). * Is a high risk CHD patient on lipid modifying therapy (LMT). * Is on any LMT with equivalent or greater LDL-C-lowering efficacy than simvastatin 40 mg. * Has Type 1 or Type 2 diabetes mellitus that is poorly controlled, or on statin therapy. * Currently engages in vigorous exercise or is on an aggressive diet regimen. * Has uncontrolled endocrine or metabolic disease, uncontrolled gout, kidney or hepatic disease, heart failure, recent peptic ulcer disease, hypersensitivity or allergic reaction to niacin or simvastatin, recent heart attack, stroke or heart surgery. * Is human immunodeficiency virus (HIV) positive. * Has taken niacin \>50 mg/day, bile-acid sequestrants, 3-hydroxy-3-methylglutaryl-coenzyme A(HMG-CoA) reductase inhibitors, ezetimibe, Cholestin™ \[red yeast rice\] and other red yeast products within 6 weeks, or fibrates within 8 weeks of randomization visit (Vi…