Drug interactions
Methylene blue + Venlafaxine
Severity: Contraindicated
Methylene blue and Venlafaxine: contraindicated 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
Methylene blue is a potent MAO-A inhibitor and, combined with serotonin reuptake inhibitors like venlafaxine, can cause severe serotonin syndrome. Reactions have occurred with intravenous methylene blue given for methemoglobinemia or during surgery.
What this interaction means in plain words
Methylene blue and Venlafaxine are not normally used together. Taking them at the same time is expected to cause harm or make one of them unsafe, so a different medicine is usually chosen for one of the two.
Why it happens
MAO-A inhibition by methylene blue added to serotonin reuptake inhibition.
What to do
Avoid unless methylene blue is needed for an emergency; then stop venlafaxine and monitor for serotonin toxicity for up to 2 weeks or until 24 hours after the last methylene blue dose, whichever comes first.
What to ask your pharmacist
- Is there an alternative to one of these two medicines for me?
- If both are essential, who is monitoring me and how often?
- Which symptoms mean I should stop and seek help straight away?
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Other interactions of Venlafaxine
- Isocarboxazid + Venlafaxine Contraindicated
- Phenelzine + Venlafaxine Contraindicated
- Procarbazine + Venlafaxine Contraindicated
- Rasagiline + Venlafaxine Contraindicated
- Safinamide + Venlafaxine Contraindicated
- Selegiline transdermal + Venlafaxine Contraindicated
Frequently asked questions
Can I take Methylene blue with Venlafaxine?
MediHelp rates the interaction as contraindicated. Methylene blue and Venlafaxine are not normally used together. Taking them at the same time is expected to cause harm or make one of them unsafe, so a different medicine is usually chosen for one of the two. Methylene blue is a potent MAO-A inhibitor and, combined with serotonin reuptake inhibitors like venlafaxine, can cause severe serotonin syndrome. Reactions have occurred with intravenous methylene blue given for methemoglobinemia or during surgery.
How serious is the interaction between Methylene blue and Venlafaxine?
MediHelp rates it contraindicated, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid unless methylene blue is needed for an emergency; then stop venlafaxine and monitor for serotonin toxicity for up to 2 weeks or until 24 hours after the last methylene blue dose, whichever comes first.
What other medicines interact with Venlafaxine?
MediHelp also lists interactions of Venlafaxine with, for example, Isocarboxazid, Phenelzine, Procarbazine. The full list is on the Venlafaxine page.
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