Pharmacologically-based Strategies for Opioid Substitution Therapy During Pregnancy

Overview

This study is a pharmacodynamic study in pregnant women evaluating the relationship between buprenorphine concentration and outcome such as opioid withdrawal symptoms , NAS scores, neurodevelopmental and neuroanatomic outcomes. Strategies to reduce opioid exposure will be explored. There are 4 specific aims but only specific aim 4 is a clinical trial and reported here. In specific aim 4, eligible consenting women on buprenorphine in an MAT clinic will be assigned to 2 dose reduction regimens and their response to dose reduction will be measured using a visual analog scale.

Opioid use has reached a staggering level and the associated deaths, neonatal consequences and economic impact are devastating. Buprenorphine and methadone are the two most commonly used medications for pregnant women in a Medication Assisted Treatment (MAT) program. Yet, the target concentration of these agents is not clearly identified. Furthermore, the relationship between drug exposure and adverse effects such as Neonatal Abstinence Syndrome and neurodevelopmental outcomes is unclear but contemporary thinking is that exposure (defined by maternal dose) is unrelated to adverse outcomes. The benefit of an MAT strategy is based on strong clinical data that demonstrates an improvement in perinatal outcomes in women participating in an MAT program. However, some women prefer to stop opioid medications entirely , but are not afforded this option in many MAT programs. The possibility that MAT is associated with some harms has received little attention but there are data that suggest that opioids adversely affect the fetal brain. If MAT is indeed associated with potential harms, then the option of Medically Supervised Withdrawal could be considered. This study will assess two dose reduction strategies in a cohort of women who desire a reduction or elimination of their opioid exposure. The magnitude group will reduce the dose by either 1 or 2 mg weekly. The frequency group will reduce their dose by 2 mg alternately in one or 2 weeks