What the FDA labels say about taking them together
Fluconazole and quinidine
Fluconazole's FDA label of April 7, 2026 names quinidine in its contraindications section; the quinidine label PlainMeds reads does not name fluconazole. The fluconazole label: “Coadministration of other drugs known to prolong the QT interval and which are metabolized via the enzyme CYP3A4 such as erythromycin, pimozide, and quinidine are contraindicated in patients receiving fluconazole. …”
Check it at the source: the fluconazole FDA label on DailyMed (effective April 7, 2026, Zydus Pharmaceuticals (USA) Inc.); the quinidine FDA label on DailyMed (effective February 1, 2018, Sun Pharmaceutical Industries, Inc.).
What does the fluconazole label say about quinidine?
Fluconazole label, contraindicationsCoadministration of other drugs known to prolong the QT interval and which are metabolized via the enzyme CYP3A4 such as erythromycin, pimozide, and quinidine are contraindicated in patients receiving fluconazole. ( See CLINICAL PHARMACOLOGY:
Fluconazole label (Mylan Pharmaceuticals Inc., April 2, 2026), drug interactionsQuinidine Although not studied in vitro or in vivo, concomitant administration of fluconazole with quinidine may result in inhibition of quinidine metabolism.
Source: FDA drug label (Fluconazole, NDA020090), Mylan Pharmaceuticals Inc., effective April 2, 2026 (SPL set 737e0fac-a2d2-4053-a0d7-edbfb6248f69), via openFDA
Source: FDA drug label (fluconazole), Zydus Pharmaceuticals (USA) Inc., effective April 7, 2026 (SPL set d1364455-1537-46d4-b093-38cca3be778f), via openFDA; the full label on DailyMed
What does the quinidine label say about fluconazole?
Quinidine's label (effective February 1, 2018) does not name fluconazole 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
| Fluconazole | Quinidine | |
|---|---|---|
| Labeled for | Fungal infections, Urinary tract infections | Atrial fibrillation |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | $0.380 per tablet 200 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