Codeine Phosphate is a type of analgesic (pain-killing) drug called an opioid or narcotic. This group of analgesics work by acting on the central nervous system of the body. Codeine is a mild analgesic which has historically been used to provide pain relief following labour and birth. It also has cough-suppressant and anti-diarrhoeal properties and is often prescribed in combination with Paracetamol for maximum pain-relieving effect.
More recently, however, there has been growing concern about prescribing codeine phosphate to breastfeeding (nursing) mothers. This is because in rare cases, some women convert codeine into morphine more rapidly or in greater quantities than others. Any drugs that are taken by the mother will pass into her breast milk, so there is the concern that some breastfed babies could be exposed to morphine in their mother’s milk. Research has shown that only mothers who are rapid metabolisers (ie just one to two per cent of the total population) are likely to be affected in this way, so the majority of mothers should be able to take codeine without any harmful side-effects to their babies. However, it is impossible to predict which mothers are rapid metabolisers and researchers have expressed concern that the use of opioids for pain relief in breastfeeding mothers could have serious adverse effects.
Consequently, some maternity units have now stopped prescribing codeine phosphate altogether, while others’ restrict its use to the lowest dose for the shortest period of time possible.
Your midwife, GP and local pharmacist will be able to advise you on those medications that are safe to take if you are breastfeeding your baby.