Codeine is a prescription drug used to treat mild to moderate pain. It is an opioid, which means it works by binding to opioid receptors in the brain and spinal cord. This binding reduces the perception of pain and produces feelings of relaxation and euphoria.
Codeine is typically taken orally in pill or liquid form. It can also be administered intravenously or intramuscularly. The drug is metabolized in the liver and excreted in the urine. Codeine has a half-life of about 3 hours, which means it takes about 3 hours for the body to eliminate half of the drug.