What the FDA labels say about taking them together
Posaconazole and tacrolimus
Posaconazole's FDA label of August 3, 2026 names tacrolimus in its drug interactions section, and tacrolimus's label names posaconazole too. The tacrolimus label: “Reduce PROGRAF dose and adjust dose based on tacrolimus whole blood trough concentrations. Early and frequent monitoring of tacrolimus whole blood trough levels should start within 1-3 days and continue monitoring as …”
Check it at the source: the posaconazole FDA label on DailyMed (effective August 3, 2026, Aurobindo Pharma Limited); the tacrolimus FDA label on DailyMed (effective July 17, 2026, Stellon Biotech Inc.).
What does the posaconazole label say about tacrolimus?
Posaconazole label, drug interactionsAt initiation of posaconazole treatment, reduce the tacrolimus dosage to approximately one-third of the original tacrolimus dosage.
Posaconazole label, warnings and precautionsWARNINGS AND PRECAUTIONS Calcineurin-Inhibitor Toxicity: Posaconazole increases concentrations of cyclosporine or tacrolimus; reduce dose of cyclosporine and tacrolimus and monitor concentrations frequently. ( 5.1 ) Arrhythmias and QTc Prolongation:
Source: FDA drug label (Noxafil, NDA022003), Merck Sharp & Dohme LLC, effective February 13, 2026 (SPL set b073b082-7b57-4423-8c06-4fd4263d6f84), via openFDA
Source: FDA drug label (POSACONAZOLE), Aurobindo Pharma Limited, effective August 3, 2026 (SPL set f8a26673-261c-4e8e-b1e1-9e23aaf7f285), via openFDA; the full label on DailyMed
What does the tacrolimus label say about posaconazole?
Tacrolimus label, drug interactionsDrug/Substance Class or Name: Strong CYP3A Inhibitors 3: Protease inhibitors (e.g, nelfinavir, telaprevir, boceprevir, ritonavir), azole antifungals (e.g., voriconazole, posaconazole, itraconazole, ketoconazole), antibiotics (e.g., clarithromycin, troleandomycin, chloramphenicol), nefazodone, letermovir, Schisandra sphenanthera extracts; Drug Interaction Effect: May increase tacrolimus whole blood trough concentrations and increase the risk of serious adverse reactions (e.g., neurotoxicity, QT prolongation). A rapid, sharp rise in tacrolimus levels may occur early, despite an immediate reduction of tacrolimus dose [see,,)].; …
Envarsus Xr label (Veloxis Pharmaceuticals, Inc, February 26, 2025), drug interactionsDrug/Substance Class or Name: Strong CYP3A Inhibitors c,, such as: Protease inhibitors (e.g., nelfinavir, telaprevir, boceprevir, ritonavir or ritonavir containing products), azole antifungals (e.g., voriconazole, posaconazole, itraconazole, ketoconazole), antibiotics (e.g., clarithromycin, troleandomycin, chloramphenicol), nefazodone, Schisandra sphenanthera extracts, cobicistat; Drug Interaction Effect: May increase tacrolimus whole blood trough concentrations and increase the risk of serious adverse reactions (e.g., neurotoxicity, QT prolongation). A rapid, sharp rise in tacrolimus levels may occur early, despite an immediate reduction of tacrolimus dose [see ].; …
Source: FDA drug label (Prograf, NDA050708), Astellas Pharma US, Inc., effective August 25, 2023 (SPL set 7f667de1-9dfa-4bd6-8ba0-15ee2d78873b), via openFDA
Source: FDA drug label (Astagraf Xl, NDA204096), Astellas Pharma US, Inc., effective January 14, 2026 (SPL set 550a5cd4-fbf2-4c09-b577-6bde8fcbdf6e), via openFDA
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
| Posaconazole | Tacrolimus | |
|---|---|---|
| Labeled for | Fungal infections | Organ transplant rejection, Eczema (atopic dermatitis) |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | $2.03 per tablet 100 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