Efficacy and safety of an extended-release niacin (Niaspan): A long-term study

Crystalline nicotinic acid (immediate-release niacin) is effective therapy for lipoprotein regulation and cardiovascular risk reduction. However, inco nvenient regimens and unpleasant side effects decrease compliance. Sustaine d-release formulations designed to circumvent these difficulties increase h epatotoxicity. Niaspan, a new US Food and Drug Administration (FDA)-approve d, once-daily, extended-release form, has been found effective and safe in short-term trials. The long-term efficacy and safety of Niaspan lipid monot herapy was studied in 517 patients (aged 21-75 years) for less than or equa l to 96 weeks in dosages less than or equal to 3,000 mg/day. Primary effica cy endpoints were low-density lipoprotein (LDL) cholesterol and apolipoprot ein B (apo B) changes from baseline; secondary efficacy endpoints were chan ges in total cholesterol, triglycerides, high-density lipoprotein (HDL) cho lesterol, lipoprotein(a), and total cholesterol/HDL-cholesterol ratio; safe ty data included adverse events and laboratory values over the 2-year study period. LDL-cholesterol levels decreased significantly: 18% at week 48 and 20% at week 96; apo 8 reduction was similar (16% decrease at week 48 and 1 9% at week 96). Large elevations in HDL cholesterol (26%, week 48; 28%, wee k 96) allowed only modest decreases in total cholesterol (12% and 13%, resp ectively), whereas total cholesterol/HDL-cholesterol ratio decreased by alm ost one third. Triglyceride and lipoprotein(a) levels were decreased by 27% and 30%, respectively (week 48), and by 28% and 40% respectively (week 96) . All changes from baseline were significant (p <0.001). Niaspan was genera lly well tolerated, although flushing was common (75%); however, there was a progressive decrease in flushing with time from 3.3 episodes in the first month to less than or equal to 1 episode by week 48, Aspirin was used by o ne third of patients before Niaspan dosing to minimize flushing episodes. A lthough serious adverse events occurred in about 10% of patients, none were considered probably or definitely related to Niaspan. Adverse events in ge neral varied widely, but their true relation to the study drug is difficult to ascertain without a placebo (control) group. No deaths occurred. There. were statistically significant changes in hepatic transaminases, alkaline phosphatase, direct bilirubin, phosphorus, glucose, amylase, end uric acid. However, these changes were mostly small and are not likely to be biologic ally or clinically significant (the decrease in phosphorus is a new Finding in therapy). No myopathy was observed. Thus, this long-term study confirms the earlier short-term findings that Niaspan is safe and effective as mono therapy in plasma lipoprotein regulation. (C) 1998 by Excerpta Medica, Inc.