Centrally acting muscle relaxant

"Centrally acting muscle relaxant" refers to a pharmacological class of drugs that reduce skeletal muscle tone and involuntary muscle spasms by acting primarily within the central nervous system. These agents—such as baclofen, diazepam, tizanidine, cyclobenzaprine, and carisoprodol—exert their effects through varied mechanisms, including enhancement of inhibitory neurotransmission (GABAergic or alpha-2 adrenergic), antagonism of excitatory pathways (such as serotonergic 5-HT​(_2_)), or general CNS depression. They are used for symptomatic relief of muscle spasms attributable to acute musculoskeletal conditions, spasticity in neurological diseases, or injury but may carry significant risks of sedation, dependence, and CNS side effects.

Other names

SpasmolyticAntispasmodicSkeletal muscle relaxant

The mechanism of action varies by specific drug within this class, not by a single target. Common mechanisms include enhancing or mimicking inhibitory neurotransmission (e.g., GABA​(_A_) or GABA​(_B_) receptor agonists, benzodiazepines), alpha-2 adrenergic receptor agonism (e.g., tizanidine), inhibition of polysynaptic reflexes in the CNS, and 5-HT​(_2_) receptor antagonism (e.g., cyclobenzaprine).