Amrix (cyclobenzaprine hydrochloride) is a brand-name drug that’s prescribed to help relieve muscle spasms in adults. Amrix comes as an extended-release oral capsule. It’s typically taken once per day ...

A dose of Flexeril (cyclobenzaprine) causes sleepiness within 30 minutes, with effects lasting for up to six to eight hours. This muscle relaxer shouldn't be taken for long—it’s typically only ...