What the FDA labels say about taking them together
Duloxetine and methylene blue
Duloxetine's FDA label of May 14, 2024 names methylene blue in its contraindications section; methylene blue's label does not name duloxetine itself but warns about its class (SNRIs (serotonin and norepinephrine reuptake inhibitors)). The duloxetine label: “… psychiatric disorders.. who are using other MAOIs such as linezolid or intravenous methylene blue because of an increased risk of serotonin syndrome.”
Check it at the source: the duloxetine FDA label on DailyMed (effective May 14, 2024, SUN PHARMACEUTICAL INDUSTRIES, INC.); the methylene blue FDA label on DailyMed (effective May 28, 2025, American Regent, Inc.).
What does the duloxetine label say about methylene blue?
Duloxetine label, contraindicationsStarting DRIZALMA SPRINKLE in a patient who is being treated with MAOIs such as linezolid or intravenous methylene blue is contraindicated because of an increased risk of serotonin syndrome [see Warnings and Precautions (5.4)].
Duloxetine label, drug interactionsExamples; Selegiline, tranylcypromine, isocarboxazid, phenelzine, linezolid, intravenous methylene blue
Duloxetine label, warnings and precautionsIf it is necessary to initiate treatment with an MAOI such as linezolid or intravenous methylene blue in a patient taking DRIZALMA SPRINKLE, discontinue DRIZALMA SPRINKLE before initiating treatment with the MAOI [see Contraindications (4), Drug Interactions (7)].
Duloxetine label (Almatica Pharma LLC, March 2, 2026), contraindicationsAllow at least 5 days after stopping Duloxetine Delayed-Release Capsules prior to initiation of an MAOI to treat psychiatric disorders. [see Dosage and Administration ( 2.7 ), Warnings and Precautions ( 5.4 )]. who are using other MAOIs such as linezolid or intravenous methylene blue because of an increased risk of serotonin syndrome [see Dosage and Administration ( 2.8 ), Warnings and Precautions ( 5.4 )].
Duloxetine label (Almatica Pharma LLC, March 2, 2026), drug interactionsPrevention or Management; Concomitant use of Duloxetine Delayed-Release Capsules is contraindicated in patients taking MAOIs, including MAOIs such as linezolid or intravenous methylene blue [see Dosage and Administration (,), Contraindications (), Warnings and Precautions ()].
Source: FDA drug label (Duloxetine, NDA219131), Almatica Pharma LLC, effective March 2, 2026 (SPL set bb2ca3bf-983c-1e4a-a91d-dc7dee66d741), via openFDA
Source: FDA drug label (DRIZALMA SPRINKLE), SUN PHARMACEUTICAL INDUSTRIES, INC., effective May 14, 2024 (SPL set b41423b8-dfec-4d79-ba3c-e43a87803d85), via openFDA; the full label on DailyMed
What does the methylene blue label say about duloxetine?
Methylene blue's label does not name duloxetine itself; it warns about its class (SNRIs (serotonin and norepinephrine 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
| Duloxetine | Methylene blue | |
|---|---|---|
| Labeled for | Depression, Anxiety, Nerve pain and fibromyalgia, Pain | n/a |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | $0.102 per capsule 30 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