Study Objective

To evaluate the dose-response for niacin-induced flushing, safety, and tolerability of niacin in the Acurox Tablet matrix (excluding oxycodone HCl) at various dose levels in both fasted and fed subjects

Design Summary

Study 107 was a Phase II single-center, randomized, double-blind study in healthy, adult male and female subjects. The Treatment Phase was conducted on an inpatient basis and included study drug dosing and safety and tolerability assessments. Each subject received eight doses of niacin (30, 60, 90, 120, 240, 360, 480, and 600 mg) and three doses of placebo administered orally in tablet form on eleven separate days in a random sequence. Half of the subjects (n=25) took each dose of study drug following a FDA standardized high fat breakfast and half (n=25) remained fasted for at least 2 hours after study drug administration. Subjects were discharged from the Clinical Research Unit on Day 11, approximately 6 hours after the last dose of study drug administration. Tolerability was rated by subjects during the Treatment Phase using a Tolerability Rating Scale (TRS) completed 3 hours after each dose of study drug. Each subject’s overall reaction to the study drug was recorded using the following 5-point scale: 0 = No effect; 1 = Easy to tolerate; 2 = Mildly unpleasant, but tolerable; 3 = Unpleasant and difficult to tolerate; 4 = Intolerable and would never take again.

Results Summary

Study 107 enrolled a total of 50 subjects. The results showed a clear niacin dose-response relationship in both Fasted and Fed subjects as assessed by the 5-point TRS. The response ranged from little or no effect at low niacin doses (30 to 90 mg) to more difficult and unpleasant symptoms at higher doses of niacin (>120 mg). With Fasted subjects, there was minimal or no effect of niacin at doses of 30 to 60 mg, with 96% of subjects reporting either “no effect” or “easy to tolerate”. Niacin was also well tolerated at doses of 90 mg, with 86% of Fasted subjects reporting either “no effect” or “easy to tolerate” and 14% reporting “mildly unpleasant, but tolerable”. The absence of any notable effects at low doses suggests that niacin will be well tolerated up to 60 mg per dose and will likely be well tolerated at 90 mg per dose. As niacin doses escalated from 120 to 360 mg, a transition occurred resulting in a larger proportion of Fasted subjects (22% to 73%) reporting mildly unpleasant, unpleasant, or intolerable effects. At doses of 480 and 600 mg, most Fasted subjects (86%) reported mildly unpleasant, unpleasant, or intolerable effects. At least 40% of subjects dosed at 480 and 600 mg reported either “unpleasant and difficult to tolerate” or “intolerable and would never take again”. The higher doses of niacin clearly produced undesirable side effects. As anticipated, niacin effects were mitigated by food. All Fed subjects (100%) receiving 30 to 240 mg niacin reported “no effect” or “easy to tolerate”. Niacin was also generally well tolerated at doses of 360 to 600 mg with most Fed subjects (68%) reporting “no effect” or “easy to tolerate”.