Codeine is a prescription medicine used to relieve mild to moderate pain and reduce coughing. It works by affecting the way the brain and nervous system respond to pain signals. While it can be effective when taken as directed by a healthcare professional it also carries risks of side effects such as drowsiness constipation and nausea. Codeine may cause dependence if misused so it is important to follow medical advice closely. Always use this medicine under the guidance of a licensed doctor and never exceed the recommended dosage to ensure safe and effective treatment.