Codeine not safe for all breastfeeding moms and their babies

Using pain treatments which contain codeine may be risky for somebreastfeeding mothers, according to researchers at The University of Western Ontario, and the Hospital for Sick Children (SickKids) in Toronto.Lead author Dr. Gideon Koren published research in the journal, Clinical Pharmacology & Therapeutics which suggests that the codeine used in some pain relief drugs can actually have harmful and even fatal results for infants when ingested by some breastfeeding mothers.

"With nearly half of all infants in North America being delivered by caesarean section orafter episiotomy, there is clearly a requirement for pain relief for mothers," says Koren. "However, our study confirms that codeine as a treatment for pain may be unsuitable and cannot be considered safe for all breastfed infants."

Koren holds the Ivey Chair in Molecular Toxicology at the Schulich School of Medicine & Dentistry at The University of Western Ontario, and is a professor of pediatrics at both Western and the University of Toronto. He is also a senior scientist in the Child Health Evaluative Sciences program at SickKids Research Institute, and director of The Motherisk Program.

Codeine is commonly used for pain relief and is recommended by the AmericanAcademy of Pediatrics as being compatible with breastfeeding. Following numerousreports through the Motherisk counseling service and the tragic death of an infant whodied from an overdose of morphine acquired from breast milk, Koren and his team,located at SickKids and The University of Western Ontario, investigated these negativereactions.

Codeine is a 'prodrug' which means that on its own it is relatively inactive. The painrelieving attributes are only activated when it is metabolized, or transformed by the bodyinto a more active pain relieving compound, morphine. Some individuals have a geneticvariance which causes them to metabolize codeine at a rapid rate, producing significantlymore morphine in their system than most of the population. While this geneticpredisposition is rare, women who possess it and who take codeine for pain whilebreastfeeding can end up exposing their babies to high levels of morphine through theirbreast milk. This can cause babies to experience central nervous system depression as aresult.

"The good news is that those breastfeeding children who were exposed to these highlevels of morphine showed dramatic improvement once they were taken off the morphinetainted breast milk," says Koren. "By removing the exposure, most children willdemonstrate a complete reversal of symptoms and show no long-term adverse effects."

Source: University of Western Ontario