Babies born to women prescribed codeine after childbirth are unlikely to be seriously harmed, a Canadian study suggests.
The pain reliever codeine is converted by the body into morphine. Doctors are concerned that some nursing mothers, depending on their ethnic background, can metabolize codeine faster than others, which can lead to a potentially toxic dose for the newborn.
In Monday's issue of the journal Clinical Toxicology, Dr. David Juurlink of the Institute for Clinical Evaluative Sciences in Toronto and his co-authors said babies born to new moms prescribed codeine after delivery were not an increased risk of death or serious harm compared with moms who were not prescribed the pain reliever.
"Over a 10-year period, we found no evidence that the prescription of codeine to women following delivery was associated with various measures of neonatal harm, including death or hospitalization," Juurlink said in a release.
The study included 7,804 infants whose mothers received a prescription for codeine shortly after delivery, and the same number of infants whose mothers gave birth at the same time, were the same age and who delivered the same way (Caesarian or vaginal delivery).
Juurlink, who also heads clinical pharmacology and toxicology at Sunnybrook Health Sciences Centre in Toronto, and his colleagues examined the medical records of the women and babies for the analysis.
"Our results should not be construed as an endorsement of codeine therapy, either during breastfeeding or in any setting," the study's authors stressed.
While codeine is popular and familiar to doctors, the drug "is an inherently irrational analgesic" because of the unpredictability of the extent of its conversion to morphine, and its interaction with other drugs, they said.
"While these results do not support the prescribing of codeine generally, they do suggest that serious neonatal harm is highly unlikely when the drug is prescribed to women following delivery."
The subjects in the study were receiving social assistance.
The researchers didn’t have information on breastfeeding pattern on the genetic makeup of the participants. It's possible some women were given codeine without a prescription.
Earlier this month, doctors at Toronto's Hospital for Sick Children advised surgeons to reconsider the use of codeine after pediatric tonsil surgery as a precaution.