Comparative effects of lovastatin and niacin in primary hypercholesterolemia. A prospective trial

Niacin and lovastatin are both effective drugs for the treatment of hypercholesterolemia and are among the drugs of first choice recommended by the adult treatment panel. To date, however, no studies have directly compared the lipoprotein-modifying effects and safety of lovastatin and niacin across their usual dosage range in patients with primary hypercholesterolemia.

The efficacy and safety of lovastatin and niacin were compared in a controlled, randomized, open-label study of 26 weeks' duration that was conducted at five lipid clinics. One hundred thirty-six patients with primary hypercholesterolemia participated in the study. Entry criteria were a low-density lipoprotein (LDL) cholesterol level greater than 4.37 mmol/L (160 mg/dL) with coronary heart disease and/or more than two coronary heart disease risk factors or an LDL cholesterol level greater than 5.19 mmol/L (190 mg/dL) in patients without coronary heart disease or less than two coronary heart disease risk factors. The study consisted of a 4-week diet run-in period after which eligible patients were randomly assigned to receive treatment with either lovastatin (20 mg/d) or niacin (1.5 g/d) for 10 weeks. On the basis of the LDL cholesterol response and patient tolerance, the doses were sequentially increased to 40 and 80 mg/d of lovastatin or 3 and 4.5 g/d of niacin after 10 and 18 weeks of treatment, respectively.

In the two patient groups, 66% of patients treated with lovastatin and 54% of patients treated with niacin underwent full dosage titration. At all time points, lovastatin was significantly (P < .01) more effective than niacin in reducing LDL cholesterol levels (26% vs 5% at week 10, 28% vs 16% at week 18, and 32% vs 23% at week 26), whereas niacin was more effective (P < .01) in increasing high-density lipoprotein cholesterol levels (6% vs 20% at week 10, 8% vs 29% at week 18, and 7% vs 33% at week 26). Niacin reduced Lp(a) lipoprotein levels by 35% at week 26, whereas lovastatin had no effect. Cutaneous flushing was the most common side effect during treatment with niacin.

Lovastatin and niacin both exerted favorable dose-dependent changes on the concentrations of plasma lipids and lipoproteins. Lovastatin was more effective in reducing LDL cholesterol concentrations, whereas niacin was more effective in increasing high-density lipoprotein cholesterol concentrations and reducing the Lp(a) lipoprotein level. Lovastatin was better tolerated than niacin, in large part because of the common cutaneous side effects of niacin.