What the FDA labels say about taking them together
Spironolactone and trandolapril
Trandolapril's FDA label of October 31, 2025 names spironolactone in its drug interactions section; spironolactone's label does not name trandolapril itself but warns about its class (ACE inhibitors). The trandolapril label: “Use of potassium-sparing diuretics, potassium supplements, or potassium-containing salt substitutes concomitantly with ACE inhibitors can increase the risk of hyperkalemia.”
Check it at the source: the spironolactone FDA label on DailyMed (effective November 28, 2025, Pfizer Laboratories Div Pfizer Inc); the trandolapril FDA label on DailyMed (effective October 31, 2025, Lupin Pharmaceuticals, Inc.).
What does the spironolactone label say about trandolapril?
Spironolactone's label does not name trandolapril itself; it warns about its class (ACE inhibitors):
Spironolactone label, warnings and precautionsExcessive diuresis may cause symptomatic dehydration, hypotension and worsening renal function, particularly in salt-depleted patients or those taking angiotensin converting enzyme inhibitors and angiotensin II receptor blockers.
Spironolactone label, drug interactionsIn general, discontinue potassium supplementation in heart failure patients who start ALDACTONE [see Warnings and Precautions (5.1) and Clinical Pharmacology (12.3) ]. Check serum potassium levels when ACE inhibitor or ARB therapy is altered in patients receiving ALDACTONE.
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
What does the trandolapril label say about spironolactone?
Trandolapril label, drug interactionsUse of potassium-sparing diuretics (spironolactone, triamterene, or amiloride), potassium supplements, or potassium-containing salt substitutes concomitantly with ACE inhibitors can increase the risk of hyperkalemia.
Source: FDA drug label (Trandolapril), Lupin Pharmaceuticals, Inc., effective October 31, 2025 (SPL set 8143a6cf-dadc-4ef7-a8db-d16d7150ad34), 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
| Spironolactone | Trandolapril | |
|---|---|---|
| Labeled for | Heart failure, Edema (fluid retention), High blood pressure | High blood pressure |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | $0.0426 per tablet 25 mg tablet | $0.157 per tablet 1 mg tablet |
| Shortage now | A presentation being discontinued | 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