Cyclobenzaprine is a skeletal muscle relaxant. It is marketed as Flexeril (5 and 10 mg tablets).

Cyclobenzaprine is a skeletal muscle relaxant. It is marketed as Flexeril (5 and 10 mg tablets), and also as Fexmid (7.5 mg tablet). Both the 5 and 10 milligram tablets are available generically. Fexmid is not available generically and few pharmacies carry it for this reason. Once-a-day extended release formulation, Amrix, has been approved by the American FDA in 2007 and is available in 15 and 30 mg capsules.

Mechanism of action
The exact mechanism of action for cyclobenzaprine is unknown. Current research appears to indicate that cyclobenzaprine acts on the locus coeruleus where it results in increased norepinephrine release, potentially through the gamma fibers which innervate and inhibit the alpha motor neurons in the ventral horn of the spinal cord.[1] Decreased firing of the alpha motor neuron results.