Codeine, also known by its generic name, is a prescription medication that is primarily used as a muscle relaxant. It is prescribed to relieve discomfort and pain caused by muscle injuries, strains, and spasms. Codeine works by affecting the communication between nerves in the central nervous system, helping to relax muscles and alleviate pain. Codeine is available in tablet form and is typically taken orally. The dosage and duration of treatment are determined by a healthcare professional based on individual needs, the severity of the muscle condition, and medical history.