Effect of probucol in hyperlipidemic patients during two years of administration.

Probucol, a new cholesterol-lowering agent, was administered to ambulatory outpatients representing several classes of hyperlipoproteinemia (HL) for two years without dietary restriction. In 32 patients with Type II HL and 12 with Type IIB HL, statistically significant reduction in mean serum cholesterol levels occurred within two weeks and persisted throughout two years of therapy at constant dosage (500 mg. twice daily). In smaller numbers of patients with Type IV HL (five patients) and Type V HL, (one patient) similar trends in mean serum cholesterol were observed but failed to achieve statistical significance. Mean triglyceride levels were generally lower during probucol therapy but varied widely between individuals. The drug was well tolerated, with no toxicity and few side effects (mild diarrhea, gas, bloating, and anal pruritus). Probucol should be a valuable addition to the therapeutic armamentarium for hypercholesterolemia.