WASHINGTON (AFP) - Some mothers who are breastfeeding and taking medicines that have codeine in them could be putting their babies at risk of a morphine overdose, the US Food and Drug Administration warned yesterday.
The warning applies to women who may be ultra-rapid metabolizers of codeine, a substance found in prescription and non-prescription medications to treat cough or aches. Once in the body, some of the codeine is metabolized into morphine.
"Mothers who are ultra-rapid metabolizers may have higher than usual levels of morphine in breast milk," the FDA said, adding that the chances of being a high-metabolizer ranged from 1 in 100 people to 28 in 100 people.
The agency launched a review of breastfeeding and codeine ingestion after a medical journal reported the case of a 13-day-old breastfed infant who died from a morphine overdose.
The mother had been taking codeine to treat episiotomy pain, and a genetic test showed she was a high metabolizer of codeine.
"The FDA is concerned that nursing infants may be at increased risk of morphine overdose if their mothers are taking codeine and are ultra-rapid metabolizers of codeine," it said in a statement.
The FDA urged doctors to "prescribe the lowest dose needed for the shortest amount of time" to nursing mothers, who "should always consult their doctors before taking any codeine containing products."
Breastfeeding women taking codeine should be on the lookout for any signs of possible overdose in their infants, such as lethargy, drowsiness or difficulty breathing, the FDA said.
Mothers could also suffer symptoms such as severe constipation, extreme lethargy and slow breathing.