Tizanidine Is Effective in the Treatment of Myofascial Pain Syndrome

Myofascial pain syndrome (MPS) is difficult to treat. The efficacy and safety of tizanidine, an alpha2-adrenergic agent with effects on spasticity and pain, in treating MPS was evaluated. Female subjects (n = 29) with MPS of 9 to > 52 weeks' duration and mean age 37.5 (range 20-51) years, who also had reduced pressure thresholds, were enrolled. Subjects were titrated up to 12 mg of tizanidine over 3 weeks and maintained for 2 weeks. Sleep was assessed via visual analog scale (VAS), pain intensity via short form McGill questionnaire including VAS, disability/level of function, and pressure threshold (tested by algometry) at baseline, weeks 3 and 5, and 1 week after tizanidine was discontinued. Patient and physician global assessments of treatment were reported at week 5. Twenty-four subjects completed the study. Pain intensity and disability decreased significantly from baseline at weeks 3 and 5 and after washout (P < .001). Pressure threshold and sleep improved for all study periods (P < .001). Tizanidine was rated as good to excellent in relieving pain by 89% of subjects and 79% of physicians. No serious adverse events occurred. Tizanidine was effective in the treatment of MPS.