Buprenorphine with, or without, Naloxone for Pregnant Women? - Review of Current Evidence and Practice in Massachusetts

Abstract

Opioid use disorder has reached the level of an epidemic. Potential complications of unsafe injections, lifestyle, overdose and withdrawal are particularly concerning in pregnant women as the risk therein extends also to the foetus. The main medications in treatment of opioid use disorder are methadone, naltrexone and buprenorphine products. Naloxone (pregnancy class: B) was carefully selected to be a part of Suboxone® in 4:1 ratio to buprenorphine (pregnancy class: C) as a deterrent for intravenous use. Naloxone's bioavailability, delivered sublingually, is minimal (<10%) yet there is a theoretical concern that a potential precipitated withdrawal could incite premature labor and fetal demise. For this reason, it is recommended that buprenorphine be used alone in this setting. However, a limited amount of data exists, showing relative safety of this combination in pregnant women when compared to other alternatives. Furthermore, current evidence in non-pregnant individuals shows that the risk of withdrawal due to naloxone is in most instances insignificant. The merit of adding naloxone as a disincentive for injecting opioids has been debated, yet the significance of preventing maternal and fetal exposures to the risk of blood stream infections, sepsis, blood-borne pathogens, bleeding and other complications is clear and warrants focused consideration. In Massachusetts, the state health insurer requires prior authorization for all forms of buprenorphine other than buprenorphine/naloxone combination films, which further complicates access to care specifically in pregnancy. Waiting periods and treatment interruptions rather than naloxone are thus much more likely to cause adverse outcomes in this population.