ABSTRACT
The toxicity of tizanidine and baclofen was studied on male rats. The oral clinical dose of tizanidine and baclofen[0.216 and o.54 mg/ 100g body weight / day, respectively]was given for one, two, three and four weeks. Chronic administration of the two drugs causes damage to the lung and a significant reduction in serum and lung levels of GSH , Vit E , Vit C and SOD activity . Four weeks treatment induced significant elevation of GPX activity and MDA levels. The two drugs, also, caused inhibitory activity on proliferation of splenocyte triggered by Con A, LPS and IL-2 production cell activities. They also produced several abnormal patterns in the EEG including increased epileptiform discharges and synchronous rhythmic activity . Diffuse slowing , with increased beta and delta activity and decreased alpha activity , with superimposed beta activity were recorded. Tizanidine had more prominent effect on the EEG than baclofen