Nimesulide+Chlorzoxazone is used in pain due to muscle spasm.

Nimesulide + Chlorzoxazone is a combination of two medicines: Nimesulide and Chlorzoxazone which relieve muscle pain. Nimesulide is a non-steroidal anti-inflammatory drug (NSAID) which works by blocking the release of certain chemical messengers that cause pain and inflammation (redness and swelling). Chlorzoxazone is a muscle relaxant. It works by acting on the centers in the brain and spinal cord to relieve the muscle stiffness or spasm.

Most side effects do not require any medical attention and disappear as your body adjusts to the medicine. Consult your doctor if they persist or if you’re worried about them