Perioperative Sedation and Sympatholysis Due to Tizanidine

Tizanidine is a short acting central muscle relaxant. It has agonist activity at noradrenergic alpha 2 receptors and inhibits the excitatory (presynaptic) motor neurons at both the spinal and supraspinal levels. Its action is through central alpha 2 receptors agonism. Tizanidine is a Food and Drug Administration (FDA) approved drug for reducing muscle tone in spastic conditions like spastic quadriparesis, multiple sclerosis, spinal cord injury and so on. Working knowledge of this kind of drugs are rarely used in the clinical practice which is useful for the anaesthesiologists to manage cases in the perioperative period. Here Authors reported the perioperative effects of Tizanidine in a patient with clitoral mass excision under general anaesthesia. All preoperative investigations were found with in normal limits. Patient was on tizanidine preoperatively for spastic quadriparesis. Intraoperatively, there were no significant fluctuations of Blood Pressure (BP) and Heart Rate (HR) even laryngoscopic response blunted. Postoperatively patient was calm and drowsy. This perioperative sympatholysis and sedation was due to tizanidine.