What the FDA labels say about taking them together
Ketoconazole and temsirolimus
Temsirolimus's FDA label of December 26, 2025 names ketoconazole in its drug interactions section; the ketoconazole label PlainMeds reads does not name temsirolimus. The temsirolimus label: “Agents Inhibiting CYP3A Metabolism Co-administration of TORISEL with ketoconazole, a potent CYP3A4 inhibitor, had no significant effect on temsirolimus C max or AUC; …”
Check it at the source: the ketoconazole FDA label on DailyMed (effective January 28, 2026, E. Fougera & Co. a division of Fougera Pharmaceuticals, LLC); the temsirolimus FDA label on DailyMed (effective December 26, 2025, Wyeth Pharmaceuticals LLC, a subsidiary of Pfizer Inc.).
What does the ketoconazole label say about temsirolimus?
Ketoconazole's label (effective January 28, 2026) does not name temsirolimus in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (ketoconazole), E. Fougera & Co. a division of Fougera Pharmaceuticals, LLC, effective January 28, 2026 (SPL set cad7c647-34a9-4e4e-83b3-8d78e58f588f), via openFDA; the full label on DailyMed
What does the temsirolimus label say about ketoconazole?
Temsirolimus label, drug interactionsAgents Inhibiting CYP3A Metabolism Co-administration of TORISEL with ketoconazole, a potent CYP3A4 inhibitor, had no significant effect on temsirolimus C max or AUC; however, sirolimus AUC increased 3.1-fold, and C max increased 2.2-fold compared to TORISEL alone.
Temsirolimus label, warnings and precautionsAgents Inhibiting CYP3A Metabolism: Strong CYP3A4 inhibitors such as atazanavir, clarithromycin, indinavir, itraconazole, ketoconazole, nefazodone, nelfinavir, ritonavir, saquinavir, and telithromycin may increase blood concentrations of the active metabolite sirolimus.
Source: FDA drug label (Torisel), NDA022088 (Pf Prism Cv), as published by Wyeth Pharmaceuticals LLC, a subsidiary of Pfizer Inc., effective December 26, 2025 (SPL set 95b7dc92-2180-42f1-8699-3c28f609e674), 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
| Ketoconazole | Temsirolimus | |
|---|---|---|
| Labeled for | Fungal infections | n/a |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $0.249 per gram 2% cream | n/a |
| 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