Codeine Can Be Fatal to Breast-Feeding Infants

The US Food and Drug Administration (FDA) adverse event and reporting program has issued a warning that medications containing codeine given to breast-feeding mothers who rapidly metabolize codeine into morphine may cause adverse effects in their infants.
Codeine is generally considered safe for use in nursing mothers; however, last year, a healthy 13-day- old breast-fed infant died from very high levels of morphine received through breast milk. The mother was taking codeine at a dose lower than that usually prescribed for post delivery pain. However, testing revealed that the mother was an ultrarapid metabolizer of codeine.
According to the FDA, depending on ethnicity, approximately anywhere from 1 to 28 per 100 individuals rapidly metabolize codeine. Unfortunately, genetic testing is the only way to determine whether someone is a rapid metabolizer.
All women who are breast feeding their infants should be extremely cautious in using codeine or products containing codeine. The FDA recommends that breast-feeding mothers be made aware of the signs of morphine overdose. They should be instructed to contact their doctor if a baby shows signs of increased sleepiness (ie, sleeping for more than 4 hours at a time), limpness, or difficulty nursing or breathing.