Flexeril, Amrix cyclobenzaprine dosing, indications, interactions, adverse effects, and more Your doctor may start you on a lowered dose or a different dosing schedule. This can help keep levels of this drug from building up too much in your body. How cyclobenzaprine (Flexeril) works is not well understood, but it helps alleviate stiffness, pain, and discomfort due to sprains, strains, or injuries to muscles. It is also sometimes prescribed off-label...