What is the best medication for opioid use disorder (OUD) treatment in a pregnant patient currently stable on methadone (methadone) maintenance therapy within an opioid treatment program (OTP)?

Management of Opioid Use Disorder in Pregnancy: Methadone vs. Buprenorphine

Methadone and buprenorphine are both safe and effective first-line medications for opioid use disorder (OUD) during pregnancy, and this patient should continue her current methadone therapy with anticipated dose adjustments as her pregnancy progresses. 1

Continuation of Current Therapy vs. Switching

For this 28-year-old woman who is stable on methadone 120 mg daily:

• Continue current methadone therapy: The patient is already stable on methadone with established take-home privileges, indicating good treatment adherence and stability. Encouraging women to remain on their prescribed medications throughout pregnancy is strongly recommended 1.
• Avoid medication switching during pregnancy: Switching medications during pregnancy could risk destabilization and potential relapse, which poses significant risks to both mother and fetus 1.
• Avoid detoxification: Acute detoxification or attempting to wean off opioids during pregnancy is not recommended due to high risk of maternal withdrawal and relapse, which can be harmful or fatal to both mother and fetus 1.

Methadone in Pregnancy: Important Considerations

Dosing Adjustments

• The patient's methadone dose will likely require significant adjustments during pregnancy, particularly in the second and third trimesters 1, 2
• Physiological changes in pregnancy (expanded volume of distribution and progesterone-increased cytochrome P450 metabolism) can result in decreased methadone levels 1
• Dosage increases or split dosing may be necessary to prevent withdrawal symptoms and cravings 1
• Coordinate closely with the OTP for dose adjustments

Maternal Benefits of Methadone

• Increased retention in treatment programs compared to buprenorphine 1
• Improved adherence to prenatal care 1
• Reduced risk of illicit opioid use 1
• Decreased risk of HIV infection associated with intravenous drug use 1

Buprenorphine vs. Methadone: Comparative Outcomes

While both medications are effective, there are some differences to consider:

Neonatal Outcomes

• Buprenorphine is associated with less severe neonatal opioid withdrawal syndrome (NOWS) 1, 3, 4
• Neonates exposed to buprenorphine typically require less medication to treat NOWS 1
• Shorter duration of treatment and hospital stays for buprenorphine-exposed neonates 1, 5
• Better outcomes in birthweight, birth length, and gestational age with buprenorphine 1

Maternal Outcomes

• No significant differences in maternal outcomes between methadone and buprenorphine 1, 4
• Similar rates of relapse, cesarean delivery, maternal weight gain, prenatal care visits, and analgesia used at delivery 1
• Better treatment retention with methadone 1, 3

Practical Management Recommendations

1. Interdisciplinary approach: Coordinate care between the OTP and obstetric team 1

2. Dosage monitoring: Regular assessment for withdrawal symptoms or cravings to guide dose adjustments 1

3. Labor and delivery planning:

   • Continue daily methadone dose throughout labor 1
   • Consider dividing maintenance medication into 2-3 doses for improved pain control 1
   • Encourage early neuraxial analgesia (epidural) 1
   • Avoid opioid agonist/antagonists like nalbuphine or butorphanol as they can precipitate withdrawal 1

4. Postpartum planning: Ensure continuation of methadone treatment postpartum 1

Common Pitfalls to Avoid

• Abrupt medication discontinuation: This can lead to withdrawal, relapse, and poor outcomes 1
• Inadequate dose adjustment: Failing to increase methadone dose as pregnancy progresses can lead to withdrawal symptoms 1, 2
• Lack of coordination: Poor communication between OTP and obstetric providers can lead to suboptimal care 1
• Stigmatization: Treating OUD as a moral failing rather than a medical condition requiring evidence-based treatment 6

In conclusion, while both methadone and buprenorphine are appropriate treatments for OUD in pregnancy, this patient should continue her current methadone therapy with anticipated dose adjustments throughout pregnancy, particularly in the later trimesters, to maintain stability and prevent withdrawal symptoms.