What the FDA labels say about taking them together
Nalmefene and naloxone
Nalmefene's FDA label of December 8, 2023 names naloxone in its warnings section; the naloxone labels PlainMeds reads (4) do not name nalmefene.
Check it at the source: the nalmefene FDA label on DailyMed (effective December 8, 2023, Chengdu Shuode Pharmaceutical Co., Ltd); the naloxone FDA label on DailyMed (effective August 17, 2026, Emergent Devices Inc.).
What does the nalmefene label say about naloxone?
Nalmefene label, warningsWhile nalmefene hydrochloride injection has a longer duration of action than naloxone in fully reversing doses, the physician should be aware that a recurrence of respiratory depression is possible, even after an apparently adequate initial response to nalmefene hydrochloride injection treatment.
Source: FDA drug label (nalmefene hydrochloride), Chengdu Shuode Pharmaceutical Co., Ltd, effective December 8, 2023 (SPL set 22d67228-6c24-47ca-afc7-52ef279520a0), via openFDA; the full label on DailyMed
What does the naloxone label say about nalmefene?
Naloxone's label (effective August 17, 2026) and its 3 other brand-application labels do not name nalmefene in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (NARCAN), Emergent Devices Inc., effective August 17, 2026 (SPL set a0ebc83d-2892-40de-bc0a-775ce90b30db), 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
| Nalmefene | Naloxone | |
|---|---|---|
| Labeled for | n/a | n/a |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $46.79 per unit 2.7 mg nasal spray | $12.74 per mL 2 mg/2 mL syringe |
| 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