What are the considerations for switching from 6 milligrams of Suboxone (buprenorphine and naloxone) to methadone?

From the Guidelines

Switching from 6 mg of Suboxone to methadone should be done with extreme caution and under close medical supervision, ideally in a specialized addiction treatment setting, due to the high risk of overdose and withdrawal complications, as highlighted in the 2022 CDC clinical practice guideline for prescribing opioids for pain 1. When considering this transition, it is crucial to understand the unique properties of both Suboxone (buprenorphine) and methadone, including their different binding affinities for opioid receptors, half-lives, and side effect profiles.

• The recommended approach involves discontinuing Suboxone completely for at least 24 hours before starting methadone to avoid precipitated withdrawal, as suggested by studies on managing acute pain in patients receiving maintenance methadone or buprenorphine therapy 1.
• An initial methadone dose of 20-30 mg is typically appropriate, with careful monitoring for the first few hours after administration, and the dose can then be adjusted gradually over days to weeks until stabilization occurs, usually requiring 60-120 mg daily for most patients.
• Patients should be aware that methadone has a longer half-life and different side effects compared to Suboxone, and daily clinic visits are typically required initially until stability is demonstrated.
• Throughout this process, withdrawal symptoms, sedation, and respiratory function should be closely monitored to ensure safety and effectiveness of the transition, emphasizing the need for a cautious and medically supervised approach, as methadone is associated with a higher risk for overdose among patients treated with ER/LA opioids, especially within the first 2 weeks of therapy, as noted in the CDC guideline 1.

From the FDA Drug Label

The initial methadone dose should be administered, under supervision, when there are no signs of sedation or intoxication, and the patient shows symptoms of withdrawal. Initially, a single dose of 20 to 30 mg of methadone will often be sufficient to suppress withdrawal symptoms Initial doses should be lower for patients whose tolerance is expected to be low at treatment entry Loss of tolerance should be considered in any patient who has not taken opioids for more than 5 days.

The patient is switching from 6 mg of suboxone, which is a partial opioid agonist, to methadone, a full opioid agonist. Caution is advised when switching from one opioid to another due to differences in potency and pharmacokinetics.

• The initial dose of methadone should be lower than the standard dose due to potential loss of tolerance.
• A dose of 20 to 30 mg of methadone may be sufficient to suppress withdrawal symptoms, but this should be determined on a case-by-case basis.
• The dose should be titrated carefully to avoid overdose and other adverse effects 2.

From the Research

Switching from Suboxone to Methadone

• The provided studies do not directly address switching from 6 mg Suboxone to methadone, but rather focus on transitioning from methadone to buprenorphine or managing opioid withdrawal with buprenorphine or methadone 3, 4, 5, 6, 7.
• Buprenorphine and methadone are both used to manage opioid withdrawal, and studies suggest they have similar effectiveness in ameliorating withdrawal symptoms, but buprenorphine may have some advantages, such as quicker resolution of withdrawal symptoms and higher completion rates of withdrawal treatment 5, 7.
• A microdosing protocol can be used to transition patients from methadone to buprenorphine, which may be relevant for patients who want to switch from Suboxone (which contains buprenorphine) to methadone, although the reverse transition is not directly addressed in the studies 3.
• Another approach is to use a short-acting opioid agonist bridge, such as hydromorphone, to transition from methadone to buprenorphine, which could potentially be adapted for switching from Suboxone to methadone, but this would require further research 4.
• The pharmacological management of opioid withdrawal has evolved over the past century, with newer approaches relying on medications like buprenorphine and clonidine, which may be relevant for managing withdrawal symptoms when switching from Suboxone to methadone 6.