Methylene Blue — Interactions & Safety Profile
Critical Interactions
SEROTONIN SYNDROME RISK. Methylene blue is a potent MAO-A inhibitor. Combined with serotonergic medications, this can cause life-threatening serotonin toxicity.
Mechanism: Methylene blue inhibits MAO-A → prevents serotonin breakdown → serotonin accumulation → serotonin syndrome.
ABSOLUTE CONTRAINDICATION. Do NOT combine with any serotonergic medication including SSRIs (fluoxetine, sertraline, etc.), SNRIs (venlafaxine, duloxetine), MAOIs, triptans, or tramadol.
Medical Disclaimer
Contraindications
G6PD deficiency
Risk of severe haemolytic anaemia. Screen all patients before use.
Severe renal insufficiency
Methylene blue is primarily renally excreted.
Known hypersensitivity to methylene blue or phenothiazine compounds
Cross-reactivity with phenothiazine class.
Monitoring Required
- •G6PD status (screen before starting)
- •Renal function (renally excreted)
- •Serotonergic medication review
Pregnancy & Nursing
Insufficient safety data. Avoid in pregnancy/breastfeeding.
Pending physician review — consult your provider before use.