Skelemus Mechanism of Action

Pharmacology: Pharmacodynamics: Eperisone Hydrochloride acts by relaxing both skeletal muscles and vascular smooth muscles, and demonstrates a variety of effects such as reduction of myotonia, improvement of circulation, and suppression of the pain reflex. The drug inhibits the vicious cycle of myotonia by decreasing pain, ischemia, and hypertonia in skeletal muscles, thus alleviating stiffness and spasticity, and facilitating muscle movement. Eperisone Hydrochloride additionally possesses analgesic action at the level of spinal cord. Eperisone Hydrochloride also improves dizziness and tinnitus associated with cerebrovascular disorders or cervical spondylosis. When eperisone is advocated alone in the treatment of spastic paralysis in patients with cerebral apoplexy, it improves the cybex torque curve and electromyogram and facilitates voluntary movements such as flexion and extension of the extremities, without reducing the muscle force. Eperisone Hydrochloride causes muscle relaxation and analgesia by acting at the level of spinal cord; it depresses both monosynaptic and polysynaptic reflexes. It dilates the blood vessels due to calcium antagonistic action on the vascular smooth muscles and muscular sympatholytic actions.
Pharmacokinetics: Eperisone Hydrochloride is very well absorbed but the immediate release drug produces low and variable-plasma concentrations due to extensive first-pass metabolism in intestine. The minimum plasma levels demonstrating a myotonolytic effect are estimated to be 300 ng/ml. However, the muscle relaxant action may depend more on the concentrations achieved in target organs rather than the plasma levels per se. Eperisone Hydrochloride is metabolized to seven metabolites via oxidation and carbonyl reduction in human liver microsome. Among them, M3 and M4 are the primary major metabolites which are generated by CYPs. Eperisone is excreted in breast milk and in urine. The elimination half-life of eperisone is 1.6-1.8 hours.