What the FDA labels say about taking them together
Erlotinib and itraconazole
Erlotinib's FDA label of June 10, 2024 names itraconazole in its drug interactions section, and itraconazole's label names erlotinib too. The erlotinib label: “Avoid co-administering erlotinib with strong CYP3A4 inhibitors or a combined CYP3A4 and CYP1A2 inhibitor (e.g., ciprofloxacin).”
Check it at the source: the erlotinib FDA label on DailyMed (effective June 10, 2024, Alembic Pharmaceuticals Limited); the itraconazole FDA label on DailyMed (effective July 13, 2026, Janssen Pharmaceuticals, Inc.).
What does the erlotinib label say about itraconazole?
Erlotinib label, drug interactionsAvoid co-administering erlotinib with strong CYP3A4 inhibitors (e.g., boceprevir, clarithromycin, conivaptan, indinavir, itraconazole, ketoconazole, lopinavir/ritonavir, nefazodone, nelfinavir, posaconazole, ritonavir, saquinavir, telithromycin, voriconazole, grapefruit or grapefruit juice) or a combined CYP3A4 and CYP1A2 inhibitor (e.g., ciprofloxacin).
Source: FDA drug label (ERLOTINIB HYDROCHLORIDE), Alembic Pharmaceuticals Limited, effective June 10, 2024 (SPL set ab6f3cb3-34a8-4492-a5d7-fb6b055a2d6b), via openFDA; the full label on DailyMed
What does the itraconazole label say about erlotinib?
Itraconazole label, drug interactionsExamples of Concomitant Drugs Within Class: Bortezomib Brentuximab-vedotin Busulfan Erlotinib Gefitinib Idelalisib Imatinib Ixabepilone; Prevention or Management: Nintedanib Panobinostat Ponatinib Ruxolitinib Sonidegib Tretinoin (oral) Vandetanib; Monitor for adverse reactions. Concomitant drug dose reduction may be necessary. For idelalisib, see also.
Tolsura label (Mayne Pharma Commercial LLC, April 23, 2025), drug interactionsBortezomib Brentuximab-vedotin Busulfan Erlotinib Gefitinib Idelalisib Imatinib Ixabepilone Nintedanib Panobinostat Ponatinib Ruxolitinib Sonidegib Vandetanib Monitor for adverse reactions.
Source: FDA drug label (Tolsura, NDA208901), Mayne Pharma Commercial LLC, effective April 23, 2025 (SPL set 306352d1-9d5a-49ad-b72d-893b99546861), via openFDA
Source: FDA drug label (SPORANOX), Janssen Pharmaceuticals, Inc., effective July 13, 2026 (SPL set a4d555fa-787c-40fb-bb7d-b0d4f7318fd0), 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
| Erlotinib | Itraconazole | |
|---|---|---|
| Labeled for | Lung cancer | Fungal infections |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | n/a | $0.910 per capsule 100 mg capsule |
| Shortage now | No current entry | A presentation being discontinued |
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