What the FDA labels say about taking them together
Dibasic/monobasic and tacrolimus
Dibasic/monobasic's FDA label of February 28, 2025 names tacrolimus in its drug interactions section; the tacrolimus labels PlainMeds reads (4) do not name dibasic/monobasic. The dibasic/monobasic label: “Products that Increase Serum Potassium Administration of Potassium Phosphates Injection to patients treated concurrently or recently with products that increase serum potassium increases the risk of severe and …”
Check it at the source: the dibasic/monobasic FDA label on DailyMed (effective February 28, 2025, Fresenius Kabi USA, LLC); the tacrolimus FDA label on DailyMed (effective July 17, 2026, Stellon Biotech Inc.).
What does the dibasic/monobasic label say about tacrolimus?
Dibasic/monobasic label, drug interactionsProducts that Increase Serum Potassium Administration of Potassium Phosphates Injection to patients treated concurrently or recently with products that increase serum potassium (e.g., potassium- sparing diuretics, ACE inhibitors, angiotensin II receptor antagonists, digoxin, or the immunosuppressants tacrolimus and cyclosporine) increases the risk of severe and potentially fatal hyperkalemia, in particular in the presence of other risk factors for hyperkalemia [see Warnings and Precautions ( 5.3 )].
Source: FDA drug label (Potassium Phosphates), Fresenius Kabi USA, LLC, effective February 28, 2025 (SPL set 475f5cd7-45bd-412a-b419-9962585d6cda), via openFDA; the full label on DailyMed
What does the tacrolimus label say about dibasic/monobasic?
Tacrolimus's label (effective July 17, 2026) and its 3 other brand-application labels do not name dibasic/monobasic in these sections. A label lists what its studies and reports found; it is not a complete list.
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
| Dibasic/monobasic | Tacrolimus | |
|---|---|---|
| Labeled for | n/a | Organ transplant rejection, Eczema (atopic dermatitis) |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | n/a | $0.970 per gram 0.1% ointment |
| 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