What the FDA labels say about taking them together
Ciprofloxacin and theophylline
Ciprofloxacin's FDA label of March 2, 2026 names theophylline in its drug interactions section, and theophylline's label names ciprofloxacin too. The theophylline label: “70% increase Ciprofloxacin Similar to cimetidine.”
Check it at the source: the ciprofloxacin FDA label on DailyMed (effective March 2, 2026, Bayer HealthCare Pharmaceuticals Inc.); the theophylline FDA label on DailyMed (effective March 10, 2026, Strides Pharma Science Limited).
What does the ciprofloxacin label say about theophylline?
Ciprofloxacin label, drug interactionsTheophylline; Avoid Use (Plasma Exposure Likely to be Increased and Prolonged); Concurrent administration of CIPRO with theophylline may result in increased risk of a patient developing central nervous system (CNS) or other adverse reactions. If concomitant use cannot be avoided, monitor serum levels of theophylline and adjust dosage as appropriate [see Warnings and Precautions ()].
Ciprofloxacin label, warnings and precautionsAlthough similar serious adverse reactions have been reported in patients receiving theophylline alone, the possibility that these reactions may be potentiated by CIPRO cannot be eliminated.
Ciloxan label (Sandoz Inc, July 30, 2024), drug interactionsHowever, the systemic administration of some quinolones has been shown to elevate plasma concentrations of theophylline, interfere with the metabolism of caffeine, enhance the effects of the oral anticoagulant, warfarin, and its derivatives, and has been associated with transient elevations in serum creatinine in patients receiving cyclosporine concomitantly.
Source: FDA drug label (Ciloxan, NDA020369), Sandoz Inc, effective July 30, 2024 (SPL set 09ca5374-2a16-4a95-91b3-70591d78254e), via openFDA
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 theophylline label say about ciprofloxacin?
Theophylline label, drug interactions70% increase Ciprofloxacin Similar to cimetidine.
Source: FDA drug label (Theophylline), Strides Pharma Science Limited, effective March 10, 2026 (SPL set b7a90ccf-9c32-40cc-9008-7e55b3da4dfd), 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 | Theophylline | |
|---|---|---|
| Labeled for | Diarrhea, Urinary tract infections, Bacterial infections | Asthma |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | $0.123 per tablet 500 mg tablet | $0.330 per tablet 300 mg tablet |
| 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