This analysis evaluated changes in pain and pain-related sleep disturbance with extended-release tramadol (tramadol ER) in patients with moderate, chronic osteoarthritis pain, and the influence of pain reduction on pain-related sleep disturbance.
Data were obtained from a 12-week, randomized, double-blind, placebo-controlled, fixed-dose study of tramadol ER 100 mg, 200 mg, 300 mg, or 400 mg once daily. Subjects reported osteoarthritis pain intensity with a 100-mm visual analog scale (VAS; 0 = no pain, 100 = extreme pain). A Sleep Problems Index score from 0 to 100 mm (0 = never, 100 = always) was determined from the mean of three subject-reported scores of pain-related sleep disturbance.
A total of 815 subjects received tramadol ER (all doses combined) and 205 received placebo. Mean pain reduction at 12 weeks was -30.4 mm and -21.5 mm for tramadol ER and placebo, respectively (p < 0.001). Tramadol ER-treated subjects were nearly twice as likely as placebo subjects to have clinically meaningful pain reduction at 12 weeks, defined as 30 mm or greater reduction (odds ratio [OR] = 1.84, P < 0.001) or 30% or greater reduction (OR = 1.95, P < 0.001) in pain. Clinically meaningful reduction of pain-related sleep disturbance at 12 weeks, defined as 16 mm or greater improvement on the Sleep Problems Index, was more common for tramadol ER than placebo (51% vs. 42%, respectively, p = 0.022). Pain reduction was associated with reduced pain-related sleep disturbance (R = 0.51). Study treatment was generally well tolerated. Possible limitations included homogeneity of pain scores at baseline and the effect of adverse events on sleep analyses.
In patients with chronic osteoarthritis pain, pain reduction is associated with decreased pain-related sleep disturbance.