Results of new research suggest that naltrexone may be an option for pregnant women who use opioids. The findings are from the first prospective study to assess use of the drug in medication-assisted treatment (MAT) in this population.
Published in the American Journal and Obstetrics & Gynecology, the data are from a cohort of 230 patients taking MAT, 121 of whom were given naltrexone and 109 of whom were given methadone or buprenorphine. The authors looked at the rate of newborns treated for symptoms of neonatal abstinence syndrome (NAS). In a subset of 20 random patients on naltrexone, they also assessed maternal and newborn blood levels of naltrexone and 6-beta-naltrexol at delivery.
In the study, the daily dosage range was 8 to 16 mg for buprenorphine and 50 to 120 mg for methadone. Patients on naltrexone must have been opioid-free for at least 7 days and have had two negative drug screens before taking the drug. The daily oral dosage was 50 mg.
At ≥ 24 weeks’ gestation, fetal heart rate (FHR) monitoring was done for ≥ 60 minutes while the initial naltrexone dose was administered. At < 24 weeks, the FHR was evaluated with Doppler or ultrasound imaging before the first dose, 30 minutes after dosing, and again at 60 minutes. Biophysical profiles were done on all the patients every other week from 28 to 32 weeks’ gestation and weekly thereafter until delivery.