Buprenorphine, an opioid, is absorbed under the tongue, but is inactivated by stomach acid if swallowed. Buprenorphine binds to opioid receptors in the brain and gut and is slow to leave the body. Therefore, it can be given once a day for opioid maintenance treatment. Women who are pregnant are in an especially difficult situation.
Studies of outcomes of abstinence-based treatment show that most pregnant women relapse to use of illicit opioid drugs. Therefore, we make an agreement with pregnant patients that we will maintain them on buprenorphine through the remainder of their pregnancy, and then taper them off buprenorphine over the first three months after delivery.