Narcotic tapering in pregnancy using long-acting morphine

DISCUSSION

The narcotic replacement and tapering program using long-acting morphine facilitated a significant decrease in neonatal withdrawal. The incidence of NAS in narcotic-exposed pregnancies fell from 29.5% in 2010 to 18.1% in 2013 (P = .003).^1,2 Despite the overall proportion of narcotic-exposed pregnancies rising from 17% to 28%, neonates requiring pharmacologic management, as a percentage of total births, fell from 2.5% to 1.5% (P = .403).^1,2

Neonates from tapered pregnancies did have significantly lower birth weights (P = .001), but the difference was not thought to be clinically relevant, with an average birth weight of 3301 g in the tapered cohort.

This prenatal narcotic-tapering program is unique in 3 ways: the use of long-acting morphine preparations, the tapering of narcotics in pregnancy, and care delivered by generalist family physicians.

Long-acting morphine is the most accessible narcotic in rural Canada. Methadone clinics and facilities are largely urban. Accessing federal funding and stock for methadone and buprenorphine in remote First Nations communities can be problematic, especially with the clinical immediacy of narcotic use and withdrawal in a pregnant patient. Fischer et al demonstrated the equivalency of long-acting morphine versus methadone in a small randomized study in 1999 (N = 48).⁸ A 2013 Cochrane review also found equivalency to methadone.⁹ The Society of Obstetricians and Gynaecologists of Canada clinical practice guidelines allow for the use of long-acting morphine, as do the 2012 Ontario provincial guidelines, particularly where methadone programs are not available.^10,11 These latter guidelines noted the epidemic of narcotic use in our region, and although methadone maintenance was generally recommended, the guideline authors recognized that our region might need to consider narcotic replacement and tapering with long-acting morphine preparations.¹²

Tapering narcotics in pregnancy raises the twin concerns of precipitating maternal and fetal withdrawal.¹³ Geographic factors in our region, with dozens of isolated remote communities, interrupt the supply chain of many commodities, including illicit narcotics. We have many patients who use intermittently owing to availability as well as poverty, making narcotic withdrawal a common challenge. Once we have initiated a long-acting morphine replacement, our tapering schedule is very gradual. The recommended 10% weekly reduction is typically spread out over a longer period of time according to patient preference, withdrawal apprehension, and physical symptoms.¹⁴ McCarthy has discussed the possibility of intrauterine fetal withdrawal in an urban context, which might be more likely to involve multidrug and daily heroin users.¹³ In this context methadone maintenance makes good sense. The absence of any common test for intrauterine withdrawal renders it a real concern, but without clear implications in our setting. Our finding that many of our patients decreased or quit narcotic use without documented measurable neonatal adverse effect is an important one. A US study in 2013 of inpatient detoxification of 95 pregnant women being treated with decreasing doses of methadone resulted in a 56% success rate and no neonatal adverse outcomes.¹⁵ In 2012, Ontario guidelines and the Centre for Addiction and Mental Health both identified our catchment area as one where traditional methadone maintenance programs would not be able to address the scope of the problem.^10,12,14 The Ontario guidelines specifically acknowledge that, in our setting, opioid tapering might be a useful approach.¹² The Centre for Addiction and Mental Health’s 2012 health alert attests: “based on recent evidence, there is minimal risk associated with tapering opioids during pregnancy.”¹⁴ All patients regularly using opioids in our study were offered tapering. Those who declined continued to be offered routine prenatal care, including fetal surveillance with regular biophysical profiles and supportive counseling. It is recommended that tapering occur in the second and third trimesters, and that is when most of our tapering occurred. However, patients were tapered so gradually with our approach that it was initiated in the first trimester (and completed in the second trimester) if the patient expressed a wish to begin reducing her narcotic use. Because decreasing the incidence of NAS was one of our program goals, we offered tapering to all regular narcotic users, and the patient ultimately decided by her comfort level whether she was maintained or slowly tapered. Patients who were occasional users constituted a large component of the exposed, nontapered cohort. This group had high quit rates and lower rates of NAS, presumably owing to self-directed narcotic management or response to the program’s supportive addiction treatment environment. All quit determinations were self-reported, supported by urine drug screening.

Another of the unique aspects of our program is the involvement of generalists with a broad scope of practice.⁴ These family physicians are involved in prenatal, intrapartum, postpartum, and neonatal care of the mother, child, and partner. They have become experienced in addiction management and can treat mother, father, and neonate. This multirole perspective, common in rural and urban family medicine, allows for an integrated approach early in pregnancy to safely reducing the incidence of NAS.¹⁶ It also reduces the need for long-distance travel to urban centres for care, which further disrupts families already dealing with addiction issues.

The rural First Nations population we serve differs from opioid-dependent patient populations encountered in the literature. Baewert and colleagues, in their subanalysis of the multicentre MOTHER [Maternal Opioid Treatment: Human Experimental Research] study, noted a difference between rural and urban settings that suggested women in urban areas were more severely affected.¹⁷ Additionally, the epidemic of oxycodone abuse encountered in our region is currently a pervasive social as well as medical issue. Clearly this is a whole-community problem, and it is being addressed directly by community-based initiatives across northwestern Ontario.^18–20 It does not just involve an isolated sector of society. This might both allow more openness in discussing the topic as well as facilitate creative, workable solutions that are a good fit for dealing with opioid dependence in pregnancy.

It can be argued that NAS has a known treatment with no known serious sequelae for the neonate and that avoiding it has limited value. The traditional approach to narcotic use of any type during pregnancy is to treat mothers with relatively high-dose methadone in the prenatal period and to provide prolonged neonatal care unit stays for the neonate postpartum. It is not generally acknowledged that this approach might unnecessarily cause a considerable disruption to family life and maternal-child bonding when a simpler approach might be effective.