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Oxycodone + Rifampin

MAJOR — Use With Caution

FDA-documented interaction. Oxycodone levels can decrease 50-85%. Pain management may fail. Dose escalation may be needed but increases risk when rifampin is stopped.

Evidence level: STRONG

What this interaction means

Rifampin can make oxycodone much less effective for pain by speeding up its breakdown in your body. You may feel like your pain medication suddenly stopped working.

How it works (mechanism)

Rifampin induces CYP3A4, dramatically increasing oxycodone metabolism. Can reduce oxycodone efficacy by 50-85%. FDA labels document this. Patients may experience pain crisis or seek dose escalation.

Practical advice

If you start rifampin while on oxycodone, tell your pain management doctor. Your pain medication dose may need adjustment. When rifampin is stopped, your oxycodone dose MUST be reduced back down to prevent overdose.

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. Oxycodone can slow gut motility — stay hydrated and consider a stool softener during the antibiotic course.

Risk factors

Higher risk for: elderly, opioid-naive patients, those with sleep apnea, respiratory conditions, concurrent CNS depressants (benzodiazepines, alcohol), liver impairment, or history of substance use disorder.

Symptoms to watch for

Increased pain (during rifampin use), then excessive sedation and respiratory depression (when rifampin is stopped if oxycodone dose was increased)

What to tell your doctor

Plan for dose adjustments in BOTH directions — increase when starting rifampin, decrease when stopping. Consider alternative pain management strategies during TB treatment.

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 Oxycodone and Rifampin together?

Rifampin can make oxycodone much less effective for pain by speeding up its breakdown in your body. You may feel like your pain medication suddenly stopped working.

When should I take Oxycodone 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. Oxycodone can slow gut motility — stay hydrated and consider a stool softener during the antibiotic course.

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

Increased pain (during rifampin use), then excessive sedation and respiratory depression (when rifampin is stopped if oxycodone dose was increased)

Are there safer alternatives to combining Oxycodone 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 Oxycodone and Rifampin?

Plan for dose adjustments in BOTH directions — increase when starting rifampin, decrease when stopping. Consider alternative pain management strategies during TB treatment.

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