What the FDA labels say about taking them together
Ciprofloxacin and erlotinib
Erlotinib's FDA label of June 10, 2024 names ciprofloxacin in its drug interactions section; the ciprofloxacin labels PlainMeds reads (3) do not name erlotinib. 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 ciprofloxacin FDA label on DailyMed (effective March 2, 2026, Bayer HealthCare Pharmaceuticals Inc.); the erlotinib FDA label on DailyMed (effective June 10, 2024, Alembic Pharmaceuticals Limited).
What does the ciprofloxacin label say about erlotinib?
Ciprofloxacin's label (effective March 2, 2026) and its 2 other brand-application labels do not name erlotinib in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Cipro), Bayer HealthCare Pharmaceuticals Inc., effective March 2, 2026 (SPL set 888dc7f9-ad9c-4c00-8d50-8ddfd9bd27c0), via openFDA; the full label on DailyMed
What does the erlotinib label say about ciprofloxacin?
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
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
| Ciprofloxacin | Erlotinib | |
|---|---|---|
| Labeled for | Diarrhea, Urinary tract infections, Bacterial infections | Lung cancer |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | $0.123 per tablet 500 mg tablet | 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