What the FDA labels say about taking them together
Quinidine and sodium bicarbonate
Quinidine's FDA label of February 1, 2018 names sodium bicarbonate in its drug interactions section; the sodium bicarbonate labels PlainMeds reads (3) do not name quinidine. The quinidine label: “Drugs that alkalinize the urine reduce renal elimination of quinidine.”
Check it at the source: the quinidine FDA label on DailyMed (effective February 1, 2018, Sun Pharmaceutical Industries, Inc.); the sodium bicarbonate FDA label on DailyMed (effective August 4, 2026).
What does the quinidine label say about sodium bicarbonate?
Quinidine label, drug interactionsDrugs that alkalinize the urine ( carbonic-anhydrase inhibitors, sodium bicarbonate, thiazide diuretics ) reduce renal elimination of quinidine.
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
What does the sodium bicarbonate label say about quinidine?
Sodium bicarbonate's label (effective August 4, 2026) and its 2 other brand-application labels do not name quinidine in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Sodium Bicarbonate 5 gr), TWIN MED LLC, effective August 4, 2026 (SPL set e325d899-d9a6-5adb-e053-2995a90ac861), 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
| Quinidine | Sodium bicarbonate | |
|---|---|---|
| Labeled for | Atrial fibrillation | Acid reflux and ulcers, Diarrhea |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | $4.92 per tablet 324 mg tablet | $0.154 per mL 8.4% vial |
| Shortage now | No current entry | In shortage |
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