A new study finds naltrexone may be safest option for pregnant women trying to stop using opioids.
When someone is struggling with opioid use disorder, medication-assisted treatment, including methadone, buprenorphine, or naltrexone, can help them recover. But for pregnant women, getting help for opioid use disorder can be fraught.
Many pregnant women with substance use disorder may fear being stigmatized, arrested, or having their children taken away after they are born, even if they take physician prescribed medication.
And stopping “cold turkey” during pregnancy is also dangerous.
To help these expectant parents and keep their children healthy, experts have been searching for the best way to treat women who are pregnant and have opioid use disorder.
A lack of information about naltrexone means many women are steered toward methadone or buprenorphine if they were pregnant and had opioid use disorder. Studies had found that methadone and buprenorphine are safe and effective for pregnant women with opioid use disorder, although infants were at risk of being born with opioid withdrawal symptoms.
Now a new study found that naltrexone appears to be safe to use for pregnant women attempting to stay off of opioids and less likely to less likely to cause withdrawal symptoms in the infant.
The small study published in Clinical Therapeutics this month found that infants who were exposed to naltrexone in utero were born at term and with healthy birth weights.
Naltrexone-exposed infants were also less likely than buprenorphine-exposed infants to show signs of neonatal abstinence syndrome (NAS).
NAS can involve a wide variety of symptoms, such as irritability, trouble sleeping, and difficulty feeding. Babies with NAS are also more likely than others to be born with low birth weight.
“There’s been a real gap in our understanding of whether naltrexone is safe in pregnancy and the best ways to utilize it,” Dr. Harshal Kirane, medical director of Wellbridge Addiction Treatment and Research in Calverton, New York, told Healthline.
“This is a very reassuring study that represents one of a few small steps that researchers have taken to start to remedy this gap in knowledge,” said Kirane, who was not involved in the study.
The new study joins a small but growing body of research suggesting that naltrexone may be safe for pregnant women and developing fetuses.
“The caveat here is that it was a very small study, and we have to conduct larger multicenter trials to fully evaluate not only the safety of naltrexone in pregnancy, but also its potential long-term effects,” he added.
The authors of the new study compared 13 mother-infant dyads that were exposed to buprenorphine in pregnancy to 6 mother-infant dyads that were exposed to naltrexone.
They found that 12 out of 13 buprenorphine-exposed infants showed signs of NAS after birth. Six of those infants were treated for NAS, before they were discharged from the hospital.
In comparison, none of the naltrexone-exposed infants were diagnosed with NAS or treated for NAS.
While these findings are promising, more research is needed to learn about the potential benefits and risks of naltrexone in pregnancy, compared to other treatments.
“Retrospective studies such as this one are prone to bias and patient differences that can influence outcomes,” Dr. Jessica Young, MPD, an associate professor in the department of obstetrics and gynecology at Vanderbilt University Medical Center, told Healthline.
For example, Young expressed concern about the exceptionally high rate of NAS that was reported among buprenorphine-exposed infants in this study.
“Their NAS rate for buprenorphine patients is much higher than most institutions,” she said. This might reflect variability in how NAS is diagnosed and managed, from one institution to another.
“At some institutions, NAS would only be diagnosed if treatment was required,” Young added.
The new study in Clinical Therapeutics suggests that naltrexone may also have benefits for preventing NAS over buprenorphine or morphine, specifically in women who are already taking naltrexone when they are pregnant.
For decades, methadone has been the standard-of-care treatment for opioid use disorder.
While it has many potential benefits, methadone often causes withdrawal symptoms or NAS in infants who’ve been exposed to it in utero.
To reduce the risk of NAS,
For women who are coping with opioid use disorder in pregnancy, Kirane and Young emphasized the importance of getting treatment from health professionals with expertise in addiction and obstetrics.
“Pregnancy represents an incredibly vulnerable time, during which the impact of opioid use disorder can be devastating, not only to the pregnant woman, but also the developing fetus and the broader family unit,” Kirane said.
If left untreated, opioid use disorder in pregnancy can negatively affect fetal development. It raises the risk of premature birth, low birth weight, and neurocognitive delays. It also increases the chances of stillbirth.
Untreated opioid use disorder can put women at risk of overdose, which may be disabling or even fatal.
It increases their risk of other mental health issues, such as depression and suicidal behavior.
Its effects on their life can also contribute to loss of employment, housing instability, interpersonal conflicts, and other socio-economic challenges.
To lower the risk of these outcomes, treatment is important.
But efforts are needed at a societal level to aid women and others who face barriers to getting treatment.
“When we look at women, and particularly pregnant women, there are a number of really challenging structural barriers that come up,” Kirane said.
Due to the high numbers of people with opioid use disorder, there are a lack of accessible treatment programs. Expectant parents may also struggle with social stigma and potential legal consequences for drug use.
“And I think in so many ways, the broader conversation has to be about how we treat individuals with substance use disorder with dignity and approach addiction care with compassion,” he said.