What the FDA labels say about taking them together
Naldemedine and quinidine
Naldemedine's FDA label of July 25, 2025 names quinidine in its drug interactions section; the quinidine label PlainMeds reads does not name naldemedine. The naldemedine label: “P-glycoprotein (P-gp) Inhibitors Clinical Impact Increase in plasma naldemedine concentrations Intervention Monitor for potential naldemedine-related adverse reactions. …”
Check it at the source: the naldemedine FDA label on DailyMed (effective July 25, 2025, BioDelivery Sciences International Inc); the quinidine FDA label on DailyMed (effective February 1, 2018, Sun Pharmaceutical Industries, Inc.).
What does the naldemedine label say about quinidine?
Naldemedine label, drug interactionsP-glycoprotein (P-gp) Inhibitors (e.g., amiodarone, captopril, cyclosporine, quercetin, quinidine, verapamil) 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) ]. Strong CYP3A inducers (e.g., rifampin): Decreased naldemedine concentrations; avoid concomitant use ( 7 ) Other opioid antagonists: Potential for additive effect and increased risk of opioid withdrawal; avoid concomitant use ( 7 ) Moderate (e.g., fluconazole) and strong (e.g., itraconazole) CYP3A4 inhibitors: Increased naldemedine concentrations; …
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
What does the quinidine label say about naldemedine?
Quinidine's label (effective February 1, 2018) does 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 (Quinidine Gluconate), Sun Pharmaceutical Industries, Inc., effective February 1, 2018 (SPL set 5023f053-fcc4-4c2c-aa59-9ec198ad185e), 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
| Naldemedine | Quinidine | |
|---|---|---|
| Labeled for | n/a | Atrial fibrillation |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | $16.26 per tablet 0.2 mg tablet | $4.92 per tablet 324 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