Is metaxalone an opiate or is it like methadone?

Im trying to figure out what metaxalone really is. It says it is a pain killer and it kinda sounds like Methadone. Well my nurse aunt gave me some free sample packages instead of wasting money on a walk in clinic, and I just want to know exactly what I'm taking before I start to take it. Thanks!

: http://alcoholdrugstreatment.info/is-metaxalone-an-opiate-or-is-it-like-methadone