Diclofenac versus lidocaine as injection therapy in myofascial pain.

Twenty-four patients with localized myofascial pain were treated with injections, 11 with 2 ml lidocaine 1% and 13 with 2 ml diclofenac (Voltaren) (50 mg) given in the trigger-point. The effect of therapy was measured by visual analogue scale (VAS) during 5 h corresponding to the expected pharmacological period of effect. Despite the small number of patients a clear trend was seen towards better treatment results with diclofenac, and after 4 h the difference between the two treatments was significant (p less than 0.05). Compared with the pain score value at the start the treatment with diclofenac gave a significant alleviation (p less than 0.05) after 3 h, whereas treatment with lidocaine did not give any significant change in pain level. The demonstrated effect of a prostaglandin synthesis inhibitor illustrates how inflammation is involved as an etiological factor in myofascial pain.