Breastfeeding & Drugs: Methadone

Methadone has been shown to transfer into breast milk. Blinick reported a milk/maternal plasma ratio of 0.83. This same study reports no adverse effects on the infant of being breast fed irrespective of the maternal methadone dose ( Blinick, 1975 ). Other studies show very minimal transfer of methadone into maternal milk, however several of these studies report that infants who were breastfed by their methadone using mothers had lower neonatal abstinence scores and earlier hospital discharge than infants fed formula ( Phillip, 2003 .

Jansson and coworkers studied 8 breastfeeding mothers on methadone dosages between 50 and 105 mg/day. They measured breast milk methadone levels on infant days of life 1, 2, 3, 4, 14, and 30. They collected both foremilk and hindmilk samples at the feeding before the mother's methadone dose and 3 hrs after the dose (peak and trough levels). Methadone concentrations in the breast milk were all low. The median breast milk:plasma ratio was between 0.36 and 0.49 for all of the samples. Levels of methadone in infant plasma collected on day 14 of life were all low. Neurobehavioral assessment of the breastfed infants on day 3, 14, and 30 were no different from a matched group of infants of non-breastfeeding mothers on methadone ( Jansson, 2008 ).

There is one report of a 4-week-old infant breast fed by his methadone using mother who was found dead in bed. His history was significant for poor growth, being cranky, having signs of a "cold" and refusal to feed ( Smialek, 1977 ).

The AAP statement Transfer of Drugs and Other Chemicals into Human Milk has placed methadone in the "usually compatible with breastfeeding" group. This is based on the assumption that the mother is receiving methadone in a structured drug treatment program. This program should include monitoring of maternal urine to detect concomitant usage of other illicit drugs ( AAP DRUGS, 2001 ).

A report from the Center for Substance Abuse Treatment of the U.S. Department of Health and Human Services recommends that Methadone using mothers who are compliant with their treatment program should be encouraged to breastfeed ( US DHHS, 1993 ).

All of this data supports breastfeeding by mothers who are in a methadone maintenance program, are monitored regularly and are adherent to the program.