What the FDA labels say about taking them together
Fluoxetine and methylene blue
Fluoxetine's FDA label of January 8, 2026 names methylene blue in its contraindications section; methylene blue's label does not name fluoxetine itself but warns about its class (serotonin reuptake inhibitors). The fluoxetine label: “Starting PROZAC in a patient who is being treated with 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 fluoxetine FDA label on DailyMed (effective January 8, 2026, Dista Products Company); the methylene blue FDA label on DailyMed (effective May 28, 2025, American Regent, Inc.).
What does the fluoxetine label say about methylene blue?
Fluoxetine label, contraindicationsStarting PROZAC in a patient who is being treated with MAOIs such as linezolid or intravenous methylene blue is also contraindicated because of an increased risk of serotonin syndrome [see Dosage and Administration ( 2.10 ) and Warnings and Precautions ( 5.2 )].
Fluoxetine label, warnings and precautionsIf it is necessary to initiate treatment with an MAOI such as linezolid or intravenous methylene blue in a patient taking PROZAC, discontinue PROZAC before initiating treatment with the MAOI [see Contraindications ( 4 ) and Drug Interactions ( 7.1 )].
Source: FDA drug label (Prozac), NDA018936 (Eli Lilly And Co), as published by Dista Products Company, effective January 8, 2026 (SPL set c88f33ed-6dfb-4c5e-bc01-d8e36dd97299), via openFDA; the full label on DailyMed
What does the methylene blue label say about fluoxetine?
Methylene blue's label does not name fluoxetine itself; it warns about its class (serotonin reuptake inhibitors):
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.
Methylene blue label, boxed warningAvoid concomitant use of PROVAYBLUE with selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), monoamine oxidase inhibitors (MAOIs) and opioids. [see Warnings and Precautions ( 5.1 ) and Drug Interactions ( 7.1 )].
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
| Fluoxetine | Methylene blue | |
|---|---|---|
| Labeled for | Depression, Anxiety, Bipolar disorder | n/a |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | $0.0519 per capsule 40 mg capsule | 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