Central muscle relaxants



Central muscle relaxants

Mephenesin
·         It was the first group of glycerol ether found to possess and used for their central muscle relaxant properties.
·         The glycerol ether probably acts by blocking spinal internucial neurons.
·         These drugs are relatively specific CNS depressants, since an animal may be cast or immobilized with doses that do not produce loss of consciousness.
·         The toxicity of mephenesin has limited its clinical use; it may produce venous thrombosis and haemolysis.

Glycerol guaicolate (Guaiphenesin)
·         Used extensively as a central muscle relaxant in the horse and to a lesser degree in dogs, pigs, cattle and sheep.
·         It may act as an agonist for glycine receptors.
·         Causes flaccid paralysis of skeletal muscle without any initial stimulation.
·         Earliest muscles to be paralyzed are limb muscles, while respiratory muscles are unaffected. 
·         Higher dose may cause thrombosis.

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