What the FDA labels say about taking them together
Hydromorphone and methylene blue
Hydromorphone's FDA label of May 14, 2026 names methylene blue in its drug interactions section; methylene blue's label does not name hydromorphone itself but warns about its class (Opioids (opioid agonists)). The hydromorphone label: “The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome.”
Check it at the source: the hydromorphone FDA label on DailyMed (effective May 14, 2026, Rhodes Pharmaceuticals LLC); the methylene blue FDA label on DailyMed (effective May 28, 2025, American Regent, Inc.).
What does the hydromorphone label say about methylene blue?
Hydromorphone label, drug interactionsSerotonergic Drugs Clinical Impact: The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome. … inhibitors (those intended to treat psychiatric disorders and also others, such as linezolid and intravenous methylene blue).
Source: FDA drug label (Hydromorphone Hydrochloride, NDA019034), Fresenius Kabi USA, LLC, effective July 15, 2026 (SPL set e034eb96-03e0-46e1-8b92-5e1f94555e7b), via openFDA
Source: FDA drug label (Hydromorphone Hydrochloride), Rhodes Pharmaceuticals LLC, effective May 14, 2026 (SPL set 37565441-0d95-4743-a695-d7b3326f58a1), via openFDA; the full label on DailyMed
What does the methylene blue label say about hydromorphone?
Methylene blue's label does not name hydromorphone itself; it warns about its class (Opioids (opioid agonists)):
Methylene blue label, boxed warningSEROTONIN SYNDROME WITH CONCOMITANT USE OF SEROTONERGIC DRUGS AND OPIOIDS PROVAYBLUE may cause serious or fatal serotonergic syndrome when used in combination with serotonergic drugs and opioids.
Methylene blue label, boxed warningSEROTONIN SYNDROME WITH CONCOMITANT USE OF SEROTONERGIC DRUGS AND OPIOIDS See full prescribing information for complete boxed warning.
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
| Hydromorphone | Methylene blue | |
|---|---|---|
| Labeled for | Pain | n/a |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | $0.219 per tablet 4 mg tablet | n/a |
| Shortage now | In shortage | 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