After the 1st of February 2018, all medicines containing codeine will no longer be available from pharmacies. The reasoning behind this decision has been stated as the potential risk of codeine tolerance, dependence, poisoning and even death (in high doses).
Codeine is an opioid drug which is similar to morphine, with a high health risk of developing tolerance or physical dependence. When tolerance occurs, codeine becomes less effective, and the body needs higher doses to create the same effect. Once dependence has occurred, discontinuing use of codeine can lead to withdrawal symptoms such as head and muscle aches, insomnia, diarrhea, mood swings and nausea. Because some of these symptoms feel similar to the symptoms over-the-counter codeine products are used to treat, people can misjudge and continue taking codeine products in higher or longer doses.