Weight change among patients engaged in medication treatment for opioid use disorder: a scoping review

Abstract

Background: Medication treatment for opioid use disorder (MOUD) is an instrumental tool in combatting opioid use and overdose. Excess weight gain associated with MOUD initiation is a potential barrier that is not well understood.Objectives: Conduct a scoping review of available studies investigating the effect of MOUD on weight.Methods: Included studies consisted of adults taking any type of MOUD (e.g. methadone, buprenorphine/naloxone, naltrexone) with data on weight or body mass index for at least two time points. Evidence was synthesized using qualitative and descriptive approaches, and predictors of weight gain including demographics, comorbid substance use, and medication dose were examined.Results: Twenty-one unique studies were identified. Most studies were uncontrolled cohort studies or retrospective chart reviews testing the association between methadone and weight gain (n = 16). Studies examining 6 months of methadone treatment reported weight gain ranging from 4.2 to 23.4 pounds. Women appear to gain more weight from methadone than men, while patients using cocaine may gain less. Racial and ethnic disparities were largely unexamined. Only three case reports and two nonrandomized studies examined the effects of either buprenorphine/naloxone or naltrexone, and potential associations with weight gain were not clear.Conclusion: The use of methadone as an MOUD appears to be associated with mild to moderate weight gain. In contrast, there is little data supporting or refuting weight gain with buprenorphine/naloxone or naltrexone. Providers should discuss the potential risk for weight gain with patients as well as prevention and intervention methods for excess weight gain.

Keywords: Medication treatment for opioid use disorder; drug-related side effects; obesity; scoping review.

Figure 1.

PRISMA flow diagram of identified, screened, and included studies.

Figure 2.

Summary of studies investigating the effect of methadone on weight reported in pounds gained. Notes. Figure 2 displays all available studies reporting the effects of methadone on weights in pounds. Studies are ordered according observation period and further sorted in ascending order for amount of weight gain. ^a This studies had two observation periods, and it is repeated to demonstrate the findings for 0–3 months and 4–6 months. ^b This study had two observation periods, both of which were greater than 6 months. The reported value is the highest reported weight gain observed in the study, which occurred after 12 months of methadone treatment.