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What the FDA labels say about taking them together

Butorphanol and methylene blue

Butorphanol's FDA label of January 2, 2026 names methylene blue in its drug interactions section; the methylene blue label PlainMeds reads does not name butorphanol. The butorphanol label: “Serotonergic Drugs The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system, such as selective serotonin reuptake inhibitors (SSRIs), serotonin and norepinephrine reuptake …”

Check it at the source: the butorphanol FDA label on DailyMed (effective January 2, 2026, Hospira, Inc.); the methylene blue FDA label on DailyMed (effective May 28, 2025, American Regent, Inc.).

What does the butorphanol label say about methylene blue?

Butorphanol label, drug interactions

Serotonergic Drugs The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system, such as selective serotonin reuptake inhibitors (SSRIs), serotonin and norepinephrine reuptake inhibitors (SNRIs), tricyclic antidepressants (TCAs), triptans, 5-HT3 receptor antagonists, drugs that affect the serotonin neurotransmitter system (e.g., mirtazapine, trazodone, tramadol), certain muscle relaxants (eg., cyclobenzaprine, metaxalone), and monoamine oxidase (MAO) inhibitors (those intended to treat psychiatric disorders and also others, such as linezolid and intravenous methylene blue), has resulted in serotonin syndrome [see PRECAUTIONS;

Source: FDA drug label (Butorphanol Tartrate), Hospira, Inc., effective January 2, 2026 (SPL set 9822ca3f-aee2-46e5-8a96-495400e65d10), via openFDA; the full label on DailyMed

What does the methylene blue label say about butorphanol?

Methylene blue's label (effective May 28, 2025) does not name butorphanol in these sections. A label lists what its studies and reports found; it is not a complete list.

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

4Butorphanol generic labelers
11Methylene blue generic labelers
ButorphanolMethylene blue
Labeled forPainn/a
Boxed warningYesYes
Pharmacy cost (NADAC)$15.46 per mL 10 mg/mL sprayn/a
Shortage nowNo current entryNo current entry

Source: FDA NDC Directory, CMS NADAC of October 7, 2026 and the FDA Drug Shortage Database (FDA files October 8, 2026)

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