Flexeril is a brand name for a muscle relaxant medication called cyclobenzaprine. There are several synonyms for Flexeril, including Amrix, Fexmid, and Comfort Pac. These medications are all used for the same purpose: to relax muscles and reduce muscle spasms. They work by blocking nerve impulses or pain sensations that are sent to the brain. In addition to these specific synonyms, there are also other muscle relaxants that are similar to Flexeril, such as Robaxin (methocarbamol) and Soma (carisoprodol). It's important to note that all of these medications should only be taken under the guidance of a healthcare provider, as they can have potential side effects and drug interactions.