Drug interactions
Morphine + Rifampin
Severity: Moderate
Morphine and Rifampin: moderate interaction.
Last updated
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
Rifampin can lower morphine exposure and may reduce analgesic effect. Patients may experience inadequate pain control while on rifampin, and opioid withdrawal or excess dosing may occur when rifampin is stopped.
What this interaction means in plain words
Morphine and Rifampin can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Why it happens
Rifampin induces UGT enzymes and possibly P-glycoprotein, increasing morphine clearance and lowering concentrations.
What to do
Monitor pain control and titrate the morphine dose upward if needed during rifampin therapy. Reassess the dose and watch for sedation or respiratory depression after rifampin is discontinued.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Morphine
- Alvimopan + Morphine Contraindicated
- Isocarboxazid + Morphine Contraindicated
- Morphine + Olanzapine / samidorphan Contraindicated
- Morphine + Phenelzine Contraindicated
- Morphine + Tranylcypromine Contraindicated
- Alfentanil + Morphine Major
Frequently asked questions
Can I take Morphine with Rifampin?
MediHelp rates the interaction as moderate. Morphine and Rifampin can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Rifampin can lower morphine exposure and may reduce analgesic effect. Patients may experience inadequate pain control while on rifampin, and opioid withdrawal or excess dosing may occur when rifampin is stopped.
How serious is the interaction between Morphine and Rifampin?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor pain control and titrate the morphine dose upward if needed during rifampin therapy. Reassess the dose and watch for sedation or respiratory depression after rifampin is discontinued.
What other medicines interact with Morphine?
MediHelp also lists interactions of Morphine with, for example, Alvimopan, Isocarboxazid, Olanzapine / samidorphan. The full list is on the Morphine page.
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