Efficacy and tolerance of repeated oral doses of tolperisone hydrochloride in the treatment of painful reflex muscle spasm: results of a prospective placebo-controlled double-blind trial.

The efficacy and safety of oral tolperisone hydrochloride (Mydocalm) in the treatment of painful reflex muscle spasm was assessed in a prospective, randomized, double-blind, placebo-controlled trial. A total of 138 patients, aged between 20 and 75 years, with painful reflex muscle spasm associated with diseases of the spinal column or proximal joints were enrolled in eight rehabilitation centers. Patients were randomized to receive either 300 mg tolperisone hydrochloride or placebo for a period of 21 days. Both treatment groups recovered during the 3 weeks rehabilitation program. However, tolperisone hydrochloride proved to be significantly superior to placebo: the change score of the pressure pain threshold as the primary target parameter significantly increased during therapy with tolperisone hydrochloride (P = 0.03, valid-case-analysis) compared to the results obtained on placebo treatment. The overall assessment of efficacy by the patient also demonstrated significant differences in favor of tolperisone hydrochloride. Best results were seen in patients aged between 40 and 60 years with a history of complaints shorter than 1 year and with concomitant physical therapy. The evaluation of safety data, i.e., adverse events, biochemical and hematological laboratory parameters, demonstrated no differences between tolperisone hydrochloride and placebo. As a conclusion tolperisone hydrochloride represents an effective and safe treatment of painful reflex muscle spasm without the typical side effects of centrally active muscle relaxants.