The effects of maternally administered methadone, buprenorphine and naltrexone on offspring: review of human and animal data

Prenatal exposure to methadone and buprenorphine: a review of the potential effects on cognitive development

The amount of opioid users receiving opioid maintenance therapy has increased significantly over the last few years. As a result, an increasing number of children are prenatally exposed to long-lasting opioids such as methadone and buprenorphine. This article reviews the literature on the cognitive development of children born to mothers in opioid maintenance therapy. Topics discussed are the effects of prenatal exposure on prematurity, somatic growth, brain volume, myelination, and the endocrine and neurotransmitter system. Social-environmental factors, including parental functioning, as well as genetic factors are also described. Areas requiring further research are identified.

Pharmacological treatment of neonatal opiate withdrawal: between the devil and the deep blue sea

Illicit drug use with opiates in pregnancy is a major global health issue with neonatal withdrawal being a common complication. Morphine is the main pharmacological agent administered for the treatment of neonatal withdrawal. In the past, morphine has been considered by and large inert in terms of its long-term effects on the central nervous system. However, recent animal and clinical studies have demonstrated that opiates exhibit significant effects on the growing brain. This includes direct dose-dependent effects on reduction in brain size and weight, protein, DNA, RNA, and neurotransmitters—possibly as a direct consequence of a number of opiate-mediated systems that influence neural cell differentiation, proliferation, and apoptosis. At this stage, we are stuck between the devil and the deep blue sea. There are no real alternatives to pharmacological treatment with opiates and other drugs for neonatal opiate withdrawal and opiate addiction in pregnant women. However, pending further rigorous studies examining the potential harmful effects of opiate exposure in utero and the perinatal period, prolonged use of these agents in the neonatal period should be used judiciously, with caution, and avoided where possible.

Long-acting injectable naltrexone for the management of patients with opioid dependence

Opioid dependence is a condition with serious clinical ramifications. Treatment has focused on detoxification, agonist therapy with methadone or buprenorphine, or remission maintenance with the opioid antagonist, naltrexone. Treatment with oral naltrexone has been limited by poor treatment adherence and relapse. Studies with long-acting formulations have shown increased treatment adherence. Extended-release injectable naltrexone has been used for the treatment of alcohol dependence, and has recently received an indication for treatment of opioid dependence from the US Food and Drug Administration. Dosing occurs once monthly and existing data with long-acting naltrexone supports efficacy of treatment for opioid dependence; however published data is sparse. Treatment with long-acting naltrexone should be monitored for hepatotoxicity, and patients should be made aware of increased risk of overdose with administration of opioids during and immediately after discontinuation of long-acting naltrexone.

Fetal neurobehavioral effects of exposure to methadone or buprenorphine

As part of a double-blind study of medication treatment for opioid dependence during pregnancy, 17 opioid-dependent pregnant women maintained on either buprenorphine or methadone underwent fetal monitoring at 24, 28, 32, and 36 weeks gestation. Maternal demographic information and infant outcomes did not significantly differ by medication group. Earlier in gestation (24 and 28 weeks), buprenorphine-exposed fetuses had higher levels of fetal heart rate variability, more accelerations in fetal heart rate and greater coupling between fetal heart rate and fetal movement than the methadone-exposed group (all ps < .05). Later in gestation (32 and 36 weeks), buprenorphine-exposed fetuses displayed less suppression of motor activity and longer duration of movements than the methadone-exposed group (all ps < .05). These results may have implications for the optimal treatment of the opioid-dependent pregnant woman.

Pregnant heroin addict: what about the baby?

Heroin misuse in pregnancy is a significant health and social problem, and it can have an adverse effect on the mother and the baby. Although heroin and methadone have no specific teratogenic potential, 48-94% of children exposed in utero will have neonatal abstinence syndrome (NAS). The primary aim of this case report is to raise awareness of NAS among clinicians and to remind them that although very common, it is not inevitable. The risk of NAS can be further minimised by offering comprehensive and co-ordinated antenatal care that addresses the various biopsychosocial needs of the pregnant woman. Further, a brief description of NAS and a review of evidence in the field of management of opioid misuse in pregnancy, as relevant to this case, are provided. We have also included the patient's own reflections on her pregnancy and treatment.