Diet and probucol in lowering cholesterol concentrations. Additive effects on plasma cholesterol concentrations in patients with familial type ii hyperlipoproteinemia

Abstract

Probucol [4,4''-(isopropylidenedithio bis)(2,6-di-t-butylphenol)], as an adjunct to diet, was evaluated for its effect on lowering the plasma cholesterol level in patients with familial hypercholesterolemia (type II). The trial had a double-blind, placebo-controlled, crossover design. About half of the 30 patients responded to a low-cholesterol modified-fat diet with a decrease in the plasma cholesterol level of approximately 13%. When probucol was added to the diet of the responders, their plasma cholesterol level was lowered a further 13%. Patients who did not respond to the diet showed reduced plasma cholesterol concentrations when receiving probucol plus the diet. Analysis of the cholesterol content of various lipoprotein fractions showed that the low-density lipoproteins accounted for most of the total plasma cholesterol level decrease. There was no effect on plasma triglyceride concentrations. Neither the 7-dehydrocholesterol nor the desmosterol level was increased in plasma of patients treated with probucol for 3 months. Probucol is useful as an adjunct to diet in lowering plasma cholesterol levels in patients with familial hypercholesterolemia. The drug was well tolerated by all patients.