Cyclobenzaprine is a centrally acting skeletal muscle relaxant structurally related to tricyclic antidepressants. Cyclobenzaprine relieves skeletal muscle spasms of local origin without interfering with muscle function. In preclinical research, cyclobenzaprine reduced skeletal muscle hyperactivity. Research indicates that it primarily acts within the central nervous system in the brain stem. Cyclobenzaprine does not work directly on skeletal muscle or the neuromuscular junction, although an overlapping action on the spinal cord may contribute to its overall skeletal muscle relaxant activity. Evidence implies that the resultant impact of cyclobenzaprine is a decline of tonic somatic motor activity, affecting both gamma(γ) and alpha(α) motor systems. Recent research suggests that cyclobenzaprine is a (5-HT2) receptor antagonist, and this additional action is responsible for its antispasmodic effect. Cyclobenzaprine effectively improves muscle spasms, reduces local pain and tenderness, and increases the range of motion in acute, painful musculoskeletal conditions. Cyclobenzaprine is an antispasmodic drug effective in treating muscle spasms. However, cyclobenzaprine is not an antispasticity drug. Therefore, cyclobenzaprine is ineffective in treating spasticity associated with cerebral or spinal cord pathology or children with cerebral palsy.

Cyclobenzaprine Serotonin antagonist pathway References