Effect of tizanidine for the prevention of post operative shivering

Post operative shivering for most of patients is uncomfortable and it can cause a lot of problems. α2 agonists (clonidine and dexmedetomidine) have been widely studied for its antishivering effect. Tizanidine is a clonidine derivative and α2-adrenoreceptor agonist that has the same effects (sedation, anxiolysis and analgesia) but lesser side effects (hypotension and bradycardia). In this study effects of oral tizanidine for prvention of postoperative shivering was assessed. In this clinical trial double blind study sixty patients (ASA I, II), aged 18-60 yr, were randomly allocated into two groups. 90 minutes before induction of general anesthesia both control and tizanidine group received placebo and 4mg oral tizanidine respectively. At the end of surgery. Incidence & intensity of shivering were assessed. Incidence & intensity of post operative shivering in the tizanidine group were significantly lower than that in the control group (p<0.01). It was possible to reduce the post operative shivering by oral administration of 4 mg tizanidine as premedication.Therefore, we recommended premedication with tizanidine for patients undergoing surgery.