The purpose of this study is to compare the effectiveness and safety of different doses of Niacin ER/Simvastatin (NS), in subjects with elevated fat levels in their blood (dyslipidemia).

The purpose of this study is to compare the efficacy and safety of different doses of Niacin ER/Simvastatin (NS), in subjects with elevated fat levels in their blood (dyslipidemia).

Inclusion Criteria:

• Patient has primary Type II hyperlipidemia or mixed dyslipidemia
• If the patient is currently taking anti-dyslipidemic medications other than Zocor, he/she is willing to withdraw from these medications
• Reasonable compliance with a standard cholesterol-lowering diet for a minimum of 4 weeks prior to screening and for the duration of the study.
• LDL-C levels and/or Non HDL-C levels above normal for patients

This study will be conducted both in the USA and internationally.

Exclusion Criteria:

• Patient has an allergy, hypersensitivity, or intolerance to niacin, statins, or their derivatives
• HbA1c ≥ 9% in diabetic patients