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Methadone + Rifampin

MAJOR — Use With Caution

FDA-documented interaction. Can precipitate opioid withdrawal. Methadone dose increases typically needed. Very careful monitoring required when starting and stopping rifampin.

Evidence level: STRONG

What this interaction means

Rifampin can cause methadone to be eliminated much faster from your body, potentially causing opioid withdrawal symptoms. For patients on methadone maintenance for addiction, this can destabilize treatment.

How it works (mechanism)

Rifampin induces CYP3A4, CYP2B6, and CYP2C19 — all involved in methadone metabolism. Can reduce methadone levels by 33-68%, potentially precipitating opioid withdrawal. FDA methadone label warns.

Practical advice

If you take methadone and need rifampin, your methadone dose will likely need significant increase. Tell your methadone clinic about any new medications. When rifampin is stopped, methadone dose must be reduced.

Timing

Take each at their prescribed times. No major timing interaction, but both can cause GI side effects (nausea, constipation). Taking the antibiotic with food may help reduce nausea. Methadone can slow gut motility — stay hydrated and consider a stool softener during the antibiotic course.

Risk factors

Opioid use disorder, concurrent substance use, lower baseline methadone dose

Symptoms to watch for

Withdrawal symptoms: anxiety, muscle aches, runny nose, sweating, yawning, insomnia, diarrhea, goosebumps, abdominal cramps

What to tell your doctor

Plan dose adjustments for both starting and stopping rifampin. Monitor for withdrawal daily. Consider alternative TB regimens. Coordinate between TB clinic and methadone program.

Safer alternatives

Opioid combinations carry serious risks including respiratory depression. Talk to your pain management specialist about non-opioid alternatives: physical therapy, NSAIDs (if appropriate), nerve blocks, or non-sedating supplements like PEA (palmitoylethanolamide) or curcumin for inflammation.

Frequently asked questions

Can I take Methadone and Rifampin together?

Rifampin can cause methadone to be eliminated much faster from your body, potentially causing opioid withdrawal symptoms. For patients on methadone maintenance for addiction, this can destabilize treatment.

When should I take Methadone vs Rifampin?

Take each at their prescribed times. No major timing interaction, but both can cause GI side effects (nausea, constipation). Taking the antibiotic with food may help reduce nausea. Methadone can slow gut motility — stay hydrated and consider a stool softener during the antibiotic course.

What symptoms should I watch for if I combine Methadone and Rifampin?

Withdrawal symptoms: anxiety, muscle aches, runny nose, sweating, yawning, insomnia, diarrhea, goosebumps, abdominal cramps

Are there safer alternatives to combining Methadone with Rifampin?

Opioid combinations carry serious risks including respiratory depression. Talk to your pain management specialist about non-opioid alternatives: physical therapy, NSAIDs (if appropriate), nerve blocks, or non-sedating supplements like PEA (palmitoylethanolamide) or curcumin for inflammation.

What should I tell my doctor about taking Methadone and Rifampin?

Plan dose adjustments for both starting and stopping rifampin. Monitor for withdrawal daily. Consider alternative TB regimens. Coordinate between TB clinic and methadone program.

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