This treatment is a strong painkiller, belonging to the opioid category of analgesics. It is designated for cases of moderate to severe pain. This might be post-operative discomfort, or pain related to an injury or chronic condition. This medicine is most commonly used in situations where paracetamol or other mild forms of pain relief have not succeeded (or are not likely to). Codeine has also been issued to treat severe coughs and diarrhea