Drug interactions
Melatonin + Rifampin
Severity: Minor
Melatonin and Rifampin: minor 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 is a potent enzyme inducer and may lower melatonin concentrations. This can reduce the sleep-promoting effect of melatonin.
What this interaction means in plain words
Melatonin and Rifampin have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Why it happens
Rifampin induces hepatic CYP1A2 and other enzymes involved in melatonin metabolism, increasing its clearance.
What to do
Assess response to melatonin and increase the dose if needed. Review the dose again when rifampin is stopped.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
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Other interactions of Melatonin
- Fluvoxamine + Melatonin Major
- Alfentanil + Melatonin Moderate
- Belladonna and opium + Melatonin Moderate
- Buprenorphine buccal + Melatonin Moderate
- Butabarbital + Melatonin Moderate
- Butalbital + Melatonin Moderate
Frequently asked questions
Can I take Melatonin with Rifampin?
MediHelp rates the interaction as minor. Melatonin and Rifampin have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Rifampin is a potent enzyme inducer and may lower melatonin concentrations. This can reduce the sleep-promoting effect of melatonin.
How serious is the interaction between Melatonin and Rifampin?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Assess response to melatonin and increase the dose if needed. Review the dose again when rifampin is stopped.
What other medicines interact with Melatonin?
MediHelp also lists interactions of Melatonin with, for example, Fluvoxamine, Alfentanil, Belladonna and opium. The full list is on the Melatonin page.
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