The treatment of spasticity in multiple sclerosis: a double-blind clinical trial of a new anti-spastic drug tizanidine compared with baclofen

Abstract

The anti-spastic effect of a new drug, tizanidine, was compared with that of baclofen in a double-blind clinical trial; 40 seriously handicapped patients with multiple sclerosis (MS) were randomly allocated treatment with one or the other drug for a 6-week period. The antispastic effect was evaluated by clinical criteria. The optimal daily dose of both drugs varied considerably from patient to patient, and was on the average 23 mg for Tizanidin and 59 mg for baclofen. To the extent an antispastic effect was observed, the 2 drugs appeared to be equally effective when given at a 1:2 ratio (mg tizanidine: mg baclofen). Side effects of both drugs were sleepiness, muscular weakness and dry mouth. Tizanidine had a mild depressive effect on blood pressure. Sudden withdrawal of both drugs was accompanied by a transient relative increase of spasticity in approximately half the patients. There were no other changes suggesting physical or psychological dependence. The present study underscores that neither baclofen nor tizanidine are ideal antispastic drugs, and emphasize the need for further research.