What the FDA labels say about taking them together
Spironolactone and tacrolimus
Spironolactone's FDA label (Spironolactone) of August 28, 2026 names tacrolimus in its drug interactions section; tacrolimus's label does not name spironolactone itself but warns about its class (Aldosterone antagonists). The spironolactone label: “Dosage adjustments of the drugs metabolized by CYP2C8 (e.g., repaglinide) and CYP3A4/5 may be necessary if they are given concurrently with spironolactone.”
Check it at the source: the spironolactone FDA label on DailyMed (effective November 28, 2025, Pfizer Laboratories Div Pfizer Inc); the tacrolimus FDA label on DailyMed (effective July 17, 2026, Stellon Biotech Inc.).
What does the spironolactone label say about tacrolimus?
Spironolactone label (Atlantic Biologicals Corp., August 28, 2026), drug interactionsDosage adjustments of the drugs metabolized by CYP2C8 (e.g., repaglinide) and CYP3A4/5 (e.g., midazolam, sirolimus and tacrolimus) may be necessary if they are given concurrently with spironolactone.
Source: FDA drug label (Spironolactone, NDA209478), Atlantic Biologicals Corp., effective August 28, 2026 (SPL set 5a203ae4-0ed1-0099-e063-6294a90abc85), via openFDA
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 tacrolimus label say about spironolactone?
Tacrolimus's label does not name spironolactone itself; it warns about its class (Aldosterone antagonists):
Tacrolimus label, warnings and precautionsConcomitant use of agents associated with hyperkalemia (e.g., potassium-sparing diuretics, ACE inhibitors, angiotensin receptor blockers) may increase the risk for hyperkalemia [see Adverse Reactions ( 6.1 )].
Tacrolimus label, warnings and precautionsCareful consideration should be given prior to use of other agents also associated with hyperkalemia (e.g., potassium-sparing diuretics, ACE inhibitors, angiotensin receptor blockers) during tacrolimus therapy [see Adverse Reactions (6.1) ].
Source: FDA drug label (Tacrolimus), Stellon Biotech Inc., effective July 17, 2026 (SPL set 6b89e8a4-9f11-42e3-8e79-fe617e7c461f), 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 | Tacrolimus | |
|---|---|---|
| Labeled for | Heart failure, Edema (fluid retention), High blood pressure | Organ transplant rejection, Eczema (atopic dermatitis) |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | $0.0426 per tablet 25 mg tablet | $0.970 per gram 0.1% ointment |
| 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