By Fred Gebhart
SAN FRANCISCO -- May 19, 2010 -- A recent study in Maine among women addicted to opiates has found that buprenorphine is safer for neonates than traditional treatment with methadone.
The research was presented in an oral paper on May 18 at the American College of Obstetricians and Gynecologists' (ACOG) 58th Annual Clinical Meeting. The paper won ACOG's Donald F. Richardson Memorial Prize.
"It has been shown that patients on methadone are more stable in terms of their physical and mental health and are more likely to receive standard prenatal care, but methadone has clear effects on the child," noted lead author Michael Czerkes, MD, Maine Medical Center, Portland, Maine. "Buprenorphine is an attractive alternative, but there are few data on the effects on neonatal outcomes. Since our patient population uses both agents, we decided to find out."
The key objection to methadone from the infant's perspective is the appearance of neonatal abstinence syndrome (NAS), a combination of symptoms that include dysfunction of the autonomic nervous system, gastrointestinal tract, and respiratory system. NAS has a number of short-term consequences, including prolonged hospital stays, prolonged monitoring, and an increased need for intravenous medications. Methadone is also inconvenient for the mother, requiring daily clinic visits, and it is subject to diversion because it is a euphoric agent.
Limited data on buprenorphine suggest that it may carry less risk for perinatal morbidity, but trials have been small and somewhat contradictory. Buprenorphine can be dispensed in 30-day packaging, which eases the burden on the mother, and is less subject to diversion because it significantly less euphoric than methadone.
Researchers at the Maine Medical Center conducted a retrospective chart review of women addicted to opioids who were using either buprenorphine or methadone and who delivered their babies at the institution between 2004 and 2008. There were 101 methadone patients and 68 buprenorphine patients available for analysis. There were no significant maternal differences between the 2 groups.
The differences between offspring of mothers in the 2 groups were dramatic, said Dr. Czerkes. The mean NAS score for buprenorphine infants was 10.69 compared with 12.5 for methadone infants (P = .0012). While the difference was statistically significant, Dr. Czerkes cautioned that it might not be clinically significant.
Other outcomes were both statistically and clinically significant. Buprenorphine infants spent a mean of 8.4 days in the hospital compared with 15.7 days for methadone infants (P < .0001) and only 48.5% of buprenorphine infants required treatment compared with 73.3% of methadone infants (P < .001).
Among buprenorphine infants who needed treatment, withdrawal symptoms appeared by day 3 or did not appear at all. Withdrawal symptoms in methadone infants appeared anywhere between days 2 and 6. "That may be a clinically significant finding," said Dr. Czerkes. "If you don't see withdrawal in these babies by day 3, they may not have withdrawal at all."
Overall, he concluded, buprenorphine appears to be safer for neonates than methadone. Researchers are recruiting patients for a larger randomized controlled trial.
[Presentation title: Buprenorphine Versus Methadone Treatment for Opiate Addiction in Pregnancy: An Evaluation of Neonatal Outcomes]
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