Codeine has a half-life of one to four hours and can be detected in urine for two to three days after ingestion.
Because codeine is metabolized to morphine, both codeine and morphine will be detected in the urine of patients prescribed codeine. If a very high dose of codeine is consumed, it is also possible to see hydrocodone and hydromorphone present at low concentrations as minor metabolites of codeine and morphine.