Comparative efficacy of once versus twice daily mevinolin in the therapy of familial hypercholesterolemia.

Mevinolin, a competitive inhibitor of the rate-limiting enzyme in cholesterol biosynthesis, is an effective hypocholesterolemic agent in patients with primary hypercholesterolemia when given in a twice-daily regimen. The present study compares the hypocholesterolemic effects of mevinolin given in a twice-daily dosage regimen with the same total dosage given either once in the morning or once in the evening in 12 patients with heterozygous familial hypercholesterolemia. Ten patients took a total daily dose of 40 mg of mevinolin and two took 20 mg. On the twice-daily dosage regimen, plasma concentrations of total cholesterol decreased 29.5% and 35.9% as compared with 21.4% and 26.9% with mevinolin given once in the morning and 27% and 32.2% with the drug given once in the evening. These values are all significantly different from baseline, but differences between the three treatment regimens do not reach statistical significance (P = 0.07 for the twice-daily versus once-in-the-morning dosage regimens). We conclude that once-daily administration of mevinolin, particularly in the evening, is an effective hypocholesterolemic regimen in patients with familial hypercholesterolemia.