What the FDA labels say about taking them together
Clarithromycin and theophylline
Clarithromycin's FDA label of April 9, 2026 names theophylline in its drug interactions section, and theophylline's label names clarithromycin too. The theophylline label: “40% increase Clarithromycin Similar to erythromycin.”
Check it at the source: the clarithromycin FDA label on DailyMed (effective April 9, 2026, Solaris Pharma Corporation); the theophylline FDA label on DailyMed (effective March 10, 2026, Strides Pharma Science Limited).
What does the clarithromycin label say about theophylline?
Clarithromycin label, drug interactionsTheophylline; Use With Caution; Theophylline: Clarithromycin use in patients who are receiving theophylline may be associated with an increase of serum theophylline concentrations [see Pharmacokinetics ]. Monitoring of serum theophylline concentrations should be considered for patients receiving high doses of theophylline or with baseline concentrations in the upper therapeutic range.
Source: FDA drug label (Clarithromycin), Solaris Pharma Corporation, effective April 9, 2026 (SPL set 4d42821d-ce7a-7d64-e063-6294a90a0875), via openFDA; the full label on DailyMed
What does the theophylline label say about clarithromycin?
Theophylline label, drug interactions40% increase Clarithromycin Similar to erythromycin.
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
| Clarithromycin | Theophylline | |
|---|---|---|
| Labeled for | Bacterial infections, Acid reflux and ulcers | Asthma |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $0.466 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