Neonatal abstinence syndrome after methadone or buprenorphine exposure.


This double-blinded study compared methadone (full mu-opioid agonist) with buprenorphine (partial mu-opioid agonist) to treat opioid dependence during pregnancy. Neonates exposed to buprenorphine and being treated for neonatal abstinence syndrome (NAS), had significantly shorter hospital stays, shorter duration of treatment, and less morphine required for treatment, compared with those exposed to methadone. Despite these benefits, mothers receiving buprenorphine dropped out of the study more frequently than those receiving methadone, possibly due to dissatisfaction with buprenorphine. Thus, reduced severity of NAS must be weighed against the potential for lower adherence with buprenorphine.


  • N=175 pregnant women with opioid dependency, randomized to receive:
    • Buprenorphine (n=86)
    • Methadone (n=89)
  • Double-blind method was used with flexible dosing. All participants received sublingual tablets (either buprenorphine or placebo) and oral liquid (either methadone or placebo, each with flavor-masking concentrates).
  • Setting: Sites in the United States, Canada, Austria.
  • Primary outcomes: number of neonates requiring treatment for NAS, assessed twice daily, for at least 10 days after birth. Modified Finnegan scale used. Peak NAS score, amount of morphine needed for treatment, duration of hospital stay, and head circumference used as well.


  • Treatment was discontinued in:
    • 18% of methadone group
    • 33% of buprenorphine group
  • Neonates exposed to buprenorphine (n=58) received significantly less morphine than those exposed to methadone (n=73). Mean morphine dose (P<0.0091):
    • 1.1 mg for buprenorphine
    • 10.4 mg for methadone
  • Hospital stay was significantly shorter for the buprenorphine group (P<0.0091):
    • 10.0 days for buprenorphine
    • 17.5 days for methadone
  • Duration of treatment for NAS was significantly shorter in the buprenorphine group (P<0.003125):
    • 4.1 days for buprenorphine
    • 9.9 days for methadone
  • No other significant differences in other outcome measures or rates of adverse effects.


Jones HE, Kaltenbach K, Heil SH, et al. Neonatal abstinence syndrome after methadone or buprenorphine exposure. N Engl J Med. 2010;363(24):2320-2331. doi:10.1056/NEJMoa1005359.

View on PubMed