[Effects of lovastatin and probucol on lipoprotein fractions in patients with hypercholesterolemia. A Brazilian multicenter study]

Abstract

Purpose: The changes in lipoproteins induced by lovastatin (L) and probucol (P) were compared in patients with primary hypercholesterolemia.

Methods: After a six-week period of screening, during which patients were maintained on lipid-lowering diet, they were administered placebo for four weeks. Those patients, whose total cholesterol (TC) remained above 250 mg/dl were eligible for active treatment. Thirty-one patients were administered L and P for 12 weeks. The initial dosage of L was 20 mg daily and it was titrated up to 40 mg daily at the end of the fifth week of treatment, whenever total cholesterol levels remained above 200 mg/dl; P was administered at a dosage of 500 mg b.i.d. through 12 weeks. Lipid analyses (TC, triglycerides-Tg, high-density cholesterol (HDL-C) non HDL cholesterol, low-density cholesterol (LDL-C) very low-density cholesterol (VLDL-C) and the ratios CT/HDL-C and laboratory safety measurements were performed during placebo period and at the end of the 5th and 12th weeks of active treatment. Clinical and ophthalmological evaluations were performed and eventual adverse reactions were recorded on different occasions.

Results: 1) L induced decrease of TC, LDL-C/HDL-C of 27.9, 34.1, 32.2, 30.9 and 36.5% respectively. These reductions were significantly more pronounced than those induced by P (21.7, 23.8, 24.5, 11.3 and 13.4% respectively); 2) L induced an increase of HDL-C of 6.8%, while P induced a reduction of HDL-C of 6.9%; 3) 54.8% and 51.6% of the patients treated with L showed reductions of the ratios TC/HDL-C and LDL-C/HDL-C respectively. The patients who were administered P showed decrease in those indices of 15.7% and 13.1% respectively; 4) L was associated with 77.4% and 77.3% of excellent and good responses for TC and LDL-C. Regular and poor responses were more frequently observed during the treatment with P (39.4% each); 5) the incidence of adverse reactions was low and tolerability was considered good for both drugs.

Conclusion: Lovastatin was more effective in the reduction of atherogenic lipoprotein fraction and in the increase of the protective one, with more pronounced reduction of the risk indices. They suggest that with the administration of L, that leads to an appropriate normalization of TC and LDL-C levels, greater benefits on morbidity and mortality of coronary disease can be achieved.