CPCP: An Update: Buprenorphine vs Methadone in Pregnancy by A Medical Student

One of our senior medical students rotating on the psychiatry consultation service delivered an outstanding Clinical Problems in Consultation Psychiatry (CPCP) presentation updating a previous medical student CPCP review on buprenorphine vs methadone in managing opiate addiction in pregnancy. The literature supports using buprenorphine overall; however, concerns remain about the risk for relapse to opiate abuse with buprenorphine.

5th ISIPT Conference in Iowa City, Iowa
Butter Cow at the Iowa State Fair

I think it’s also vitally important to emphasize that using a validated assessment tool such as the Clinical Opiate Withdrawal Scale (COWS) is essential–along with some degree of skepticism about subjective symptoms of withdrawal. It is potentially dangerous to administer methadone to someone who is not in objective withdrawal.

There is also the issue of altered pharmacokinetics in pregnancy which is important to take into account. Pregnant women may need divided doses of methadone and may require increasing doses as pregnancy progresses:

Shiu, J. R. and M. H. Ensom (2012). “Dosing and monitoring of methadone in pregnancy: literature review.” Can J Hosp Pharm 65(5): 380-386.
BACKGROUND: The pharmacokinetics of methadone is altered during pregnancy, but the most appropriate dosing and monitoring regimen has yet to be identified. OBJECTIVE: To review dosing and monitoring of methadone therapy in pregnancy. METHODS: A literature search was performed in several databases (PubMed, MEDLINE, Embase, International Pharmaceutical Abstracts, and the Cochrane Database of Systematic Reviews) from inception to May 2012. The search terms were “methadone”, “pregnancy”, “pharmacokinetic”, “clearance”, “metabolism”, “therapeutic drug monitoring”, and “methadone dosing”. Additional papers were identified by searching the bibliographies of primary and review articles. All English-language primary articles related to methadone pharmacokinetics in pregnancy were included. Articles not related to maternal outcomes were excluded. RESULTS: The literature search yielded 1 case report and 10 studies discussing use of methadone by pregnant women. Methadone pharmacokinetics in pregnancy has been studied in 3 pharmacokinetic trials, and split dosing of methadone in pregnant women has been described in 1 case report and 3 dosing trials. Only 4 trials evaluated monitoring of methadone concentration in pregnancy. The studies included in this review confirm that methadone pharmacokinetics is altered in pregnancy and is potentially correlated with increases in maternal withdrawal symptoms. Insufficient evidence is available to warrant routine monitoring of serum methadone concentrations in pregnant women with opioid dependence. CONCLUSIONS: Few studies of methadone pharmacokinetics and therapeutic drug monitoring are available for pregnant women with opioid dependence. Although it is known that methadone pharmacokinetics is altered in pregnancy, there is insufficient evidence to guide dosage adjustments and serum concentration monitoring. Until further studies are available, regular follow-up of maternal withdrawal symptoms and empiric dosage adjustments throughout pregnancy are still recommended.

As I listened to Viral and reflected on the ways we learn how to improve the ways we practice to emphasize safe and effective methods of assessing and treating our patients, it occurs to me that sometimes the best way to do this is for clinicians to collaborate with each other, even by email between medical centers that are separated by great distances. This was prompted by Viral’s thoughtful presentation and led to useful progress. It’s too bad that creative ways of teaching each other about better ways to practice medicine regarding issues that are relevant to what we do every day are “non-approved” products for Maintenance of Certification (MOC).

Don’t get me started on that–but I still think we can lead our own way. Good teachers are everywhere, even if they don’t identify themselves as such. I was reminded of that when I discovered that Dottie Ray died recently. She was a pioneer and leader for women in radio news broadcasting and delivered the Dottie Ray Show from her apartment for decades. I was one of her guests many years ago when I was a junior resident, talking about National Depression Screening Day. In her own way, she was a great teacher.

Let’s take Dottie Ray’s example and lead our own way.

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