What the FDA labels say about taking them together
Erythromycin and tacrolimus
Erythromycin's FDA label of August 1, 2024 names tacrolimus in its drug interactions section, and tacrolimus's label names erythromycin too. The tacrolimus label: “Monitor tacrolimus whole blood trough concentrations and reduce ENVARSUS XR dose if needed.”
Check it at the source: the erythromycin FDA label on DailyMed (effective August 1, 2024, Teva Pharmaceuticals USA, Inc.); the tacrolimus FDA label on DailyMed (effective July 17, 2026, Stellon Biotech Inc.).
What does the erythromycin label say about tacrolimus?
Erythromycin label, drug interactionsThere have been spontaneous or published reports of CYP3A based interactions of erythromycin with cyclosporine, carbamazepine, tacrolimus, alfentanil, disopyramide, rifabutin, quinidine, methyl-prednisolone, cilostazol, vinblastine, and bromocriptine.
Ery-Ped label (Azurity Pharmaceuticals, Inc. (formerly Arbor Pharmaceuticals), December 16, 2023), drug interactionsReduction of sildenafil dosage should be considered. (See Viagra package insert.) There have been spontaneous or published reports of CYP3A based interactions of erythromycin with cyclosporine, carbamazepine, tacrolimus, alfentanil, disopyramide, rifabutin, quinidine, methylprednisolone, cilostazol, vinblastine, and bromocriptine.
Erythromycin label (Dr. Reddy's Labratories Inc., September 25, 2025), drug interactionsReduction of sildenafil dosage should be considered. (See Viagra package insert.) There have been spontaneous or published reports of CYP3A based interactions of erythromycin with carbamazepine, cyclosporine, tacrolimus, alfentanil, disopyramide, bromocriptine, rifabutin, quinidine methylprednisolone, cilostazol, and vinblastine.
Source: FDA drug label (Ery-Ped, NDA050207), Azurity Pharmaceuticals, Inc. (formerly Arbor Pharmaceuticals), effective December 16, 2023 (SPL set 04775721-ab87-4b66-808c-d67a21032385), via openFDA
Source: FDA drug label (Erythromycin, NDA050536), Dr. Reddy's Labratories Inc., effective September 25, 2025 (SPL set a2dcb48a-212c-1b0c-ec35-ee2ade85847f), via openFDA
Source: FDA drug label (Erythromycin), Teva Pharmaceuticals USA, Inc., effective August 1, 2024 (SPL set 75a0bd5a-d09f-483b-bfd8-f8343b149eb2), via openFDA; the full label on DailyMed
What does the tacrolimus label say about erythromycin?
Tacrolimus label, drug interactionsDrug/Substance Class or Name: Mild or Moderate CYP3A Inhibitors: Clotrimazole, antibiotics (e.g., erythromycin, fluconazole), calcium channel blockers (e.g., verapamil, diltiazem, nifedipine, nicardipine), amiodarone, danazol, ethinyl estradiol, cimetidine, lansoprazole and omeprazole; Drug Interaction Effect: May increase tacrolimus whole blood trough concentrations and increase the risk of serious adverse reactions (e.g., neurotoxicity, QT prolongation) [see,,)].; Recommendations: Monitor tacrolimus whole blood trough concentrations and reduce tacrolimus dose if needed [ see,) and ].
Envarsus Xr label (Veloxis Pharmaceuticals, Inc, February 26, 2025), drug interactionsDrug/Substance Class or Name: Mild or Moderate CYP3A Inhibitors, such as: antibiotics (e.g., erythromycin), calcium channel blockers (e.g., verapamil, diltiazem, nifedipine, nicardipine), amiodarone, danazol, ethinyl estradiol, cimetidine, lansoprazole and omeprazole, azole antifungals (e.g., clotrimazole, fluconazole, isavuconazole), imatinib, nilotinib, letermovir; Drug Interaction Effect: May increase tacrolimus whole blood trough concentrations and increase the risk of serious adverse reactions (e.g., neurotoxicity, QT prolongation) [see,, ].; Recommendations: Monitor tacrolimus whole blood trough concentrations and reduce ENVARSUS XR dose if needed [see and ].
Source: FDA drug label (Envarsus Xr, NDA206406), Veloxis Pharmaceuticals, Inc, effective February 26, 2025 (SPL set de2315b0-6344-43ac-9aea-3e3b68d828e7), via openFDA
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
| Erythromycin | Tacrolimus | |
|---|---|---|
| Labeled for | Bacterial infections, Acne | Organ transplant rejection, Eczema (atopic dermatitis) |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | $1.96 per tablet 250 mg tablet | $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