Can I Breastfeed on Buprenorphine?
We all want the best for our children and that includes doing whatever it takes to protect them from harm. As a result, it is logical to be weary about breastfeeding if you're on a prescription medication such as Buprenorphine due to the concern about passing that drug to your newborn through your breast milk. While it is true that almost every drug that is in a mother's bloodstream will pass into her breast milk to some degree, these levels are usually low and pose no serious risk to the baby. However, there are always exceptions and you should consult your OB/GYN or pediatrician for further advice.
In regards to Buprenorphine, there have been several studies examining the safety of this medication during lactation and in general it is recommended that mother's on Buprenorphine should be encouraged to breastfeed their children unless there is some other contraindication preventing them from doing so. Research has shown that the levels of Buprenorphine in a mother's breast milk is very low and additionally Buprenorphine has poor oral bio-availability so would be even lower in an infant's bloodstream. Furthermore, most studies have shown that the amount that passes to the newborn is not even enough to prevent or treat neonatal abstinence syndrome (NAS) and that supplemental treatment with morphine may be required. However, a recent study did just show that there is a trend towards requiring less morphine for those infants exclusively breastfed by mothers on Buprenorphine.

Does It Matter If I'm On Suboxone vs Subutex While Breastfeeding
While most women were probably maintained on Subutex while pregnant they may have been switched back to Suboxone after they delivered. As you may recall, Suboxone differs from Subutex in that Suboxone contains Naloxone to help prevent abuse. Concentrations of Naloxone are even lower in a mother's breast milk with minimal transmission to an infant if at all so it would be perfectly acceptable to breastfeed while on Suboxone. This question was specifically asked and addressed in a case involving a newborn with a rash that was possibly being attributed to the Naloxone in Suboxone but later determined to be due to another cause. If anything, you should be monitoring for increased drowsiness while breastfeeding and monitoring for signs of withdrawal if breastfeeding is stopped suddenly. While generally considered safe and encouraged, more studies are needed to determine the long-term effects of infants breastfed by mothers on Buprenorphine.