Open-label dose-titration safety and efficacy study of tizanidine hydrochloride in the treatment of spasticity associated with chronic stroke

Background and Purpose-Spasticity is a frequently observed motor impairment that develops after stroke; it can cause pain and disability in those affe cted. The objective of the present study was to evaluate the safety and eff icacy of tizanidine, a centrally acting ce-adrenergic agonist, in the treat ment of stroke-related spasticity. Methods-Forty-seven patients, who were a minimum of 6 months poststroke and had significant spasticity, were studied at 4 centers. Tizanidine was admi nistered in an open-label manner for 16 weeks, beginning at 2 mg/d and slow ly titrated to a maximum of 36 mg/d. The Modified Ashworth Scale. muscle st rength testing, functional assessments, and Pain and Functional Spasticity Questionnaires were administered at baseline and at 4, 8, 16, and 18 weeks (after I week off tizanidine). Results-Spasticity was significantly improved between baseline and week 16, with a decrease in total upper extremity Modified Ashworth Scale score of 2.80 +/-0.47 (P <0.0001). No decline in strength was noted. Treatment with tizanidine resulted in a significant improvement in pain intensity (P=0.037 5), quality of life (P=0.0001), and physician assessment of disability (P=0 .0001). The most frequent side effects were somnolence (62%) and dizziness (32%). No serious adverse events were considered to be drug related. Ten of 47 patients (21%) were able to reach the maximum daily dosage of 36 mg. Conclusions-Overall, the data suggest that tizanidine is safe and efficacio us in the treatment of stroke-related spasticity, preserving muscle strengt h while reducing muscle tone and painful spasms in affected patients.