As an adjunct to diet to reduce elevated total-C, LDL-C, apo B & triglyceride levels in patients w/ primary hypercholesterolemia (heterozygous familial & nonfamilial) & mixed dyslipidemia (Frederickson types IIa & IIb). Adjunctive therapy to diet for the treatment of patients w/ elevated serum triglycerides (Frederickson type IV). Treatment of patients w/ primary dysbetalipoproteinemia (Frederickson type III) who do not respond adequately to diet. Reduction of total & LDL-C in patients with homozygous familial hypercholesterolemia as an adjunct to other lipid-lowering treatments.