What the FDA labels say about taking them together
Potassium citrate and spironolactone
Potassium citrate's FDA label of December 2, 2021 names spironolactone in its contraindications section; the spironolactone labels PlainMeds reads (2) do not name potassium citrate. The potassium citrate label: “Concomitant administration of Urocit-K and a potassium-sparing diuretic should be avoided since the simultaneous administration of these agents can produce severe hyperkalemia.”
Check it at the source: the potassium citrate FDA label on DailyMed (effective December 2, 2021, Mission Pharmacal Company); the spironolactone FDA label on DailyMed (effective November 28, 2025, Pfizer Laboratories Div Pfizer Inc).
What does the potassium citrate label say about spironolactone?
Potassium citrate label, contraindicationsSuch conditions include: chronic renal failure, uncontrolled diabetes mellitus, acute dehydration, strenuous physical exercise in unconditioned individuals, adrenal insufficiency, extensive tissue breakdown or the administration of a potassium-sparing agent (such as triamterene, spironolactone or amiloride).
Potassium citrate label, drug interactionsConcomitant administration of Urocit-K and a potassium-sparing diuretic (such as triamterene, spironolactone or amiloride) should be avoided since the simultaneous administration of these agents can produce severe hyperkalemia.
Source: FDA drug label (UROCIT-K), Mission Pharmacal Company, effective December 2, 2021 (SPL set 72cdea1b-2240-41db-987d-86d5c6aaa978), via openFDA; the full label on DailyMed
What does the spironolactone label say about potassium citrate?
Spironolactone's label (effective November 28, 2025) and its 1 other brand-application label do not name potassium citrate in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Aldactone), Pfizer Laboratories Div Pfizer Inc, effective November 28, 2025 (SPL set 0fed2822-3a03-4b64-9857-c682fcd462bc), 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
| Potassium citrate | Spironolactone | |
|---|---|---|
| Labeled for | n/a | Heart failure, Edema (fluid retention), High blood pressure |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $0.175 per tablet 10 mEq tablet | $0.0426 per tablet 25 mg tablet |
| Shortage now | No current entry | A presentation being discontinued |
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