What the FDA labels say about taking them together
Erythromycin and naldemedine
Naldemedine's FDA label of July 25, 2025 names erythromycin in its drug interactions section; the erythromycin labels PlainMeds reads (4) do not name naldemedine. The naldemedine label: “Moderate and Strong CYP3A Inhibitors Clinical Impact Increase in plasma naldemedine concentrations Intervention Monitor for potential naldemedine-related adverse reactions.”
Check it at the source: the erythromycin FDA label on DailyMed (effective August 1, 2024, Teva Pharmaceuticals USA, Inc.); the naldemedine FDA label on DailyMed (effective July 25, 2025, BioDelivery Sciences International Inc).
What does the erythromycin label say about naldemedine?
Erythromycin's label (effective August 1, 2024) and its 3 other brand-application labels do not name naldemedine in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Erythromycin), Teva Pharmaceuticals USA, Inc., effective August 1, 2024 (SPL set 75a0bd5a-d09f-483b-bfd8-f8343b149eb2), via openFDA; the full label on DailyMed
What does the naldemedine label say about erythromycin?
Naldemedine label, drug interactionsModerate (e.g., fluconazole, atazanavir, aprepitant, diltiazem, erythromycin) and Strong (e.g., itraconazole, ketoconazole, clarithromycin, ritonavir, saquinavir) CYP3A Inhibitors Clinical Impact Increase in plasma naldemedine concentrations [see Clinical Pharmacology (12.3) ] Intervention Monitor for potential naldemedine-related adverse reactions [see Adverse Reactions (6.1) ].
Source: FDA drug label (SYMPROIC), NDA208854 (Bdsi), as published by BioDelivery Sciences International Inc, effective July 25, 2025 (SPL set b1a1256c-a1eb-4abe-ab1e-30e4711afd16), 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
| Erythromycin | Naldemedine | |
|---|---|---|
| Labeled for | Bacterial infections, Acne | n/a |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $1.96 per tablet 250 mg tablet | $16.26 per tablet 0.2 mg tablet |
| 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