What the FDA labels say about taking them together
Buspirone and methylene blue
Buspirone's FDA label of December 22, 2023 names methylene blue in its contraindications section, and methylene blue's label names buspirone too. The buspirone label: “Starting buspirone in a patient who is being treated with reversible MAOIs such as linezolid or intravenous methylene blue is also contraindicated because of an increased risk of serotonin syndrome.”
Check it at the source: the buspirone FDA label on DailyMed (effective December 22, 2023, Unichem Pharmaceuticals (USA), Inc.); the methylene blue FDA label on DailyMed (effective May 28, 2025, American Regent, Inc.).
What does the buspirone label say about methylene blue?
Buspirone label, contraindicationsStarting buspirone in a patient who is being treated with reversible MAOIs such as linezolid or intravenous methylene blue is also contraindicated because of an increased risk of serotonin syndrome (see WARNINGS , DOSAGE AND ADMINISTRATION and DRUG INTERACTIONS ).
Buspirone label, warningsSerotonin Syndrome The development of a potentially life-threatening serotonin syndrome has been reported with SNRIs, SSRIs, and other serotonergic drugs, including buspirone, alone but particularly with concomitant use of other serotonergic drugs (including triptans), with drugs that impair metabolism of serotonin (in particular, MAOIs, including reversible MAOIs such as linezolid and intravenous methylene blue), or with antipsychotics or other dopamine antagonists.
Source: FDA drug label (Buspirone Hydrochloride), Unichem Pharmaceuticals (USA), Inc., effective December 22, 2023 (SPL set a6bdf140-075e-445e-a62d-633a4b97f3a8), via openFDA; the full label on DailyMed
What does the methylene blue label say about buspirone?
Methylene blue label, drug interactionsAvoid concomitant use of PROVAYBLUE with medicinal products that enhance serotonergic transmission including antidepressants like SSRIs (selective serotonin reuptake inhibitors), SNRIs (serotonin and norepinephrine reuptake inhibitors), MAOIs (monoamine oxidase inhibitors), bupropion, buspirone, clomipramine, mirtazapine, linezolid, opioids, and dextromethorphan because of the potential for serious CNS reactions, including potentially fatal serotonin syndrome.
Source: FDA drug label (PROVAYBLUE), NDA204630 (Provepharm Sas), as published by American Regent, Inc., effective May 28, 2025 (SPL set 4f6848e5-35ed-4046-b13c-3032b5ba3232), via openFDA; the full label on DailyMed
These are the labels' own sentences. PlainMeds does not grade interactions; a pharmacist or prescriber can say what they mean for one person's medicines.
Both medicines on the record
| Buspirone | Methylene blue | |
|---|---|---|
| Labeled for | Anxiety | n/a |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | $0.043 per tablet 15 mg tablet | n/a |
| Shortage now | No current entry | No current entry |
Source: FDA NDC Directory, CMS NADAC of October 7, 2026 and the FDA Drug Shortage Database (FDA files October 8, 2026)
What next?
- Check more medicines together
- up to five at once