Drug interactions
Methadone + Secobarbital
Severity: Major
Methadone and Secobarbital: major interaction.
Last updated Sources: US FDA label
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Barbiturates induce methadone metabolism, potentially causing withdrawal or reduced effect, while also adding to CNS and respiratory depression. The opposing effects make the combination unpredictable and potentially dangerous.
What this interaction means in plain words
Methadone and Secobarbital can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Methadone belongs to Musculoskeletal; Secobarbital belongs to Central Nervous System.
Why it happens
CYP3A4 induction lowers methadone levels, with additive CNS and respiratory depression.
What to do
Avoid the combination where possible. If used, monitor for withdrawal and sedation, and reassess methadone dosing when the barbiturate is started or stopped.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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References
Other interactions of Methadone
- Alvimopan + Methadone Contraindicated
- Calcium / magnesium / potassium / sodium oxybates + Methadone Contraindicated
- Droperidol + Methadone Contraindicated
- Ibutilide + Methadone Contraindicated
- Isocarboxazid + Methadone Contraindicated
- Lefamulin + Methadone Contraindicated
Other interactions of Secobarbital
- Calcium / magnesium / potassium / sodium oxybates + Secobarbital Contraindicated
- Doravirine + Secobarbital Contraindicated
- Elbasvir / grazoprevir + Secobarbital Contraindicated
- Elvitegravir / cobicistat / emtricitabine / tenofovir df + Secobarbital Contraindicated
- Isavuconazonium + Secobarbital Contraindicated
- Lonafarnib + Secobarbital Contraindicated
Frequently asked questions
Can I take Methadone with Secobarbital?
MediHelp rates the interaction as major. Methadone and Secobarbital can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Barbiturates induce methadone metabolism, potentially causing withdrawal or reduced effect, while also adding to CNS and respiratory depression. The opposing effects make the combination unpredictable and potentially dangerous.
How serious is the interaction between Methadone and Secobarbital?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid the combination where possible. If used, monitor for withdrawal and sedation, and reassess methadone dosing when the barbiturate is started or stopped.
What other medicines interact with Methadone?
MediHelp also lists interactions of Methadone with, for example, Alvimopan, Calcium / magnesium / potassium / sodium oxybates, Droperidol. The full list is on the Methadone page.
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