Methylene Blue and Amitriptyline: Interaction Details
AI-assisted, pharmacist-reviewed · AI content regenerated Jul 11, 2026 · Source data updated Jul 2, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Amitriptyline
Methylene Blue
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
Taking these two together is not recommended. Amitriptyline (Elavil) raises serotonin, a chemical messenger in your brain. Methylene blue acts like an MAO inhibitor, meaning it slows down the breakdown of serotonin. Put them together and serotonin can climb too high, leading to a dangerous reaction called serotonin syndrome.
Warning signs include a racing or high fever, sweating, shaking, muscle twitching, confusion, a fast heartbeat, and stomach upset. This can become serious quickly. The good news is your care team knows about this combination and can plan safely around it. Please talk with your doctor or pharmacist before either drug is started, and get medical help right away if you feel these symptoms.
Contraindicated combination. Methylene blue is a potent MAO inhibitor; it blocks MAO-mediated serotonin metabolism. Combined with amitriptyline (a TCA that increases serotonergic activity via reuptake inhibition), this produces excess synaptic serotonin and a risk of potentially fatal serotonin syndrome (autonomic instability, hyperthermia, neuromuscular abnormalities, altered mental status, GI symptoms). Evidence is rated probable.
- Non-urgent: discontinue amitriptyline at least 14 days before methylene blue.
- Urgent, no alternative, benefit outweighs risk: stop amitriptyline immediately; use lowest effective methylene blue dose.
- Monitor for serotonin syndrome for 2 weeks or until 24 h after the last methylene blue dose, whichever is first.
- Amitriptyline may resume 24 h after the last methylene blue dose.
What happens
An increased risk of serotonin syndrome (labile blood pressure, hyperthermia, neuromuscular abnormalities, mental status changes, gastrointestinal symptoms)
Interaction Deep Dive
Combining amitriptyline with methylene blue (an MAOI) is contraindicated1, as taking them together can lead to serotonin syndrome that may be fatal 2. When methylene blue treatment is not urgently needed, amitriptyline should be stopped a minimum of 14 days before methylene blue is started. For a patient already receiving amitriptyline who urgently requires methylene blue, where no other pharmacological or non-pharmacological option exists and the anticipated benefits are judged to exceed the risk of serotonin syndrome, amitriptyline has to be stopped without delay 3. The dose of methylene blue should be kept as low as possible 2. Surveillance for serotonin syndrome should continue for 2 weeks, or until 24 hours have passed since the final methylene blue dose, whichever occurs first. Amitriptyline can be restarted 24 hours following the last methylene blue dose 3.
Why it happens (mechanism)
Inhibition of MAO-mediated serotonin metabolism by methylene blue
How to manage this interaction
This combination is generally avoided, but your care team can manage the situation safely.
- Keep taking your amitriptyline as prescribed, and do not start or stop anything on your own.
- Make sure every provider knows you take amitriptyline before methylene blue is given.
- When it is not an emergency, your team may plan to stop amitriptyline about 2 weeks before methylene blue.
- If methylene blue is urgently needed, your team may pause amitriptyline, use the lowest possible dose, and watch you closely for up to 2 weeks.
Get urgent help for fever, sweating, shaking, muscle stiffness, confusion, or a racing heartbeat.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
1 report — tap to read
a) Serious reactions have been reported, such as hypertensive crises, severe convulsions, and death, in patients who received tricyclic antidepressants together with MAOIs 1.
Common questions
Can I take Methylene Blue and Amitriptyline together?
Amitriptyline plus methylene blue can cause dangerous serotonin syndrome and is a contraindicated combination, so let your care team plan the timing and monitoring. Seek immediate help for fever, agitation, muscle twitching, or a racing heartbeat. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Methylene Blue and Amitriptyline interaction?
It is rated contraindicated. These should generally not be used together.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How is the Methylene Blue and Amitriptyline interaction managed?
This combination is generally avoided, but your care team can manage the situation safely. Keep taking your amitriptyline as prescribed, and do not start or stop anything on your own. Make sure every provider knows you take amitriptyline before methylene blue is given. When it is not an emergency, your team may plan to stop amitriptyline about 2 weeks before methylene blue. If methylene blue is ur… Management is individual — always follow your own care team's guidance.
How strong is the evidence for this interaction?
The evidence is graded "probable". Good supporting evidence, though not definitively proven.
From our Q&A
Real reader questions about these medications, each personally answered by our pharmacist:
Questions for your pharmacist
- Does my dose of Methylene Blue or Amitriptyline need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there a safer alternative to one of these medications for me?
References (3)
- Product Information: amitriptyline hcl oral tablets, amitriptyline hcl oral tablets. Vintage Pharmaceuticals,LLC, Huntsville, AL, 2006. DailyMed
- Product Information: PROVAYBLUE(R) intravenous injection, methylene blue intravenous injection. American Regent, Inc. (per FDA), Shirley, NY, 2023. DailyMed
- U.S. Food and Drug Administration: FDA Drug Safety Communication: Serious CNS reactions possible when methylene blue is given to patients taking certain psychiatric medications. U.S. Food and Drug Administration. Silver Spring, MD. 2011.
Keep reading about Amitriptyline
Keep reading about Methylene Blue
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