Doctors caring for pregnant women addicted to opioids may face a difficult choice—should they treat with methadone or buprenorphine? While a study published in 2010 in the New England Journal of Medicine provides some guidance, physicians must consider the individual circumstances of the mother, says study co-author Karol Kaltenbach, PhD, Director of Maternal Addiction Treatment Education and Research at Jefferson Medical College in Philadelphia.

She spoke recently about treating pregnant women for opioid addiction at the 2012 Ruth Fox Course for Physicians, part of the American Society for Addiction Medicine annual conference.

Methadone is the recommended treatment for pregnant women who are addicted to opioids. When properly used, methadone is considered relatively safe for the newborn. But it is associated with neonatal abstinence syndrome (NAS), a group of symptoms caused by opioid withdrawal in the newborn that often require medical treatment and long hospitalization.

The 2010 study found that compared with methadone, buprenorphine resulted in similar maternal outcomes, but buprenorphine was better than methadone in reducing withdrawal symptoms in the newborns. This meant babies required less medication and less time in the hospital.

The Maternal Opioid Treatment: Human Experimental Research (MOTHER) trial included 131 pregnant women who were addicted to opioids, such as heroin or prescription pain medication, with low rates of other illicit drug use. This meant the researchers knew that cases of NAS were caused by opioids, and not other drugs, said Dr. Kaltenbach, who is also Professor of Pediatrics and Professor of Psychiatry and Human Behavior at Jefferson Medical College.

Buprenorphine is a newer medication, and less is known about its effect in pregnant women and their babies. “Our study was not seeking to replace methadone as an option for treatment of opioid dependence,” Dr. Kaltenbach says. “We wanted to clearly delineate the different effects of the two medications.”

There have been no changes in the recommendations for treatment of opioid-addicted pregnant women since the study was published, she notes. “A physician’s decision has to be made on what’s clinically best for the mother,” she says. “If a woman has been successfully maintained on buprenorphine, she should continue on that drug, and the same holds for methadone.”

She says the transition from methadone to buprenorphine can be difficult. “Even though the infant outcomes are better at birth, and we want to minimize the hospital stay for the babies, we also need to consider the health of the mother—if methadone is effective for her, she should stay on it.”

Pregnant women who are addicted to opioids who have never been treated for their addiction are probably good candidates to start buprenorphine, Dr. Kaltenbach states. “If that doesn’t prove to be effective, she can easily be transferred to methadone.”

Many doctors are uncomfortable starting pregnant women on buprenorphine, since there is less experience of using buprenorphine in this population. “Our trial had very rigorous monitoring conditions, in that we hospitalized all of the women for induction onto buprenorphine or methadone so we could maximize their safety and ensure they weren’t going into withdrawal,” Dr. Kaltenbach says. “But that’s not necessarily feasible in community-based organizations or private practices that are treating pregnant women with opioid addiction.”

The study also focused on women who were addicted to opioids, but not to other substances, such as benzodiazepines or alcohol. “In real life, most women using opioids also use benzodiazepines, which affects NAS, making it longer in duration and harder to treat,” she notes.

Dr. Kaltenbach and her colleagues received additional funding to follow the infants in the study through their first three years to see how they developed. The data is currently being analyzed.