A PLACEBO-CONTROLLED RANDOMIZED CLINICAL-TRIAL OF NORTRIPTYLINE FOR CHRONIC LOW-BACK-PAIN

To assess the efficacy of nortriptyline, a tricyclic antidepressant, a s an analgesic in chronic back pain without depression, we conducted a randomized, double-blind, placebo-controlled, 8-week trial in 78 men recruited from primary care and general orthopedic settings, who had c hronic low back pain (pain at T-6 or below on a daily basis for 6 mont hs or longer). Of these 57 completed the trial; of the 21 who did nor complete, four were withdrawn because of adverse effects. The interven tion consisted of inert placebo or nortriptyline titrated to within th e therapeutic range for treating major depression (50-150 ng/ml). The main outcome endpoints were pain (Descriptor Differential Scale), disa bility (Sickness Impact Profile), health-related quality of life (Qual ity of Well-Being Scale), mood (Beck Depression Inventory, Spielberger State Anxiety Inventory, Hamilton Anxiety/Depression Rating Scales), and physician rated outcome (Clinical Global Impression). Reduction in pain intensity scores was significantly greater for participants rand omized to nortriptyline (difference in mean change 1.68, 95% -0.001, C I -3.36, P = 0.050), with a reduction of pain by 22% compared to 9% on placebo. Reduction in disability marginally favored nortriptyline (P = 0.055), but health-related quality of life, mood, and physician rati ngs of overall outcome did not differ significantly between treatments . Subgroup analyses of study completers supported the intent-to-treat analysis. Also, completers with radicular pain on nortriptyline (n = 5 ) had significantly (P < 0.05) better analgesia and overall outcome th an did those on placebo (n = 6). The results suggest noradrenergic mec hanisms are relevant to analgesia in back pain. This modest reduction in pain intensity suggests that physicians should carefully weigh the risks and benefits of nortriptyline in chronic back pain without depre ssion. (C) 1998 International Association for the Study of Pain. Publi shed by Elsevier Science B.V.