What the FDA labels say about taking them together
Ephedrine and theophylline
Ephedrine's FDA label of September 16, 2024 names theophylline in its drug interactions section, and theophylline's label names ephedrine too. The theophylline label: “300% increase Ephedrine Synergistic CNS effects. Increased frequency of nausea, nervousness, and insomnia.”
Check it at the source: the ephedrine FDA label on DailyMed (effective September 16, 2024, Nexus Pharmaceuticals, LLC); the theophylline FDA label on DailyMed (effective March 10, 2026, Strides Pharma Science Limited).
What does the ephedrine label say about theophylline?
Ephedrine label, drug interactionsTheophylline: Concomitant use of EMERPHED and EMERPHED-PFS may increase the frequency of nausea, nervousness, and insomnia.
Source: FDA drug label (Akovaz, NDA208289), Exela Pharma Sciences, LLC, effective November 27, 2020 (SPL set e92f3eda-33eb-4b34-9e8b-db8d32a5dbd9), via openFDA
Source: FDA drug label (Emerphed PFS), Nexus Pharmaceuticals, LLC, effective September 16, 2024 (SPL set 14601778-93ac-43ec-b66b-5a942317133f), via openFDA; the full label on DailyMed
What does the theophylline label say about ephedrine?
Theophylline label, drug interactions300% increase Ephedrine Synergistic CNS effects. Increased frequency of nausea, nervousness, and insomnia.
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
| Ephedrine | Theophylline | |
|---|---|---|
| Labeled for | Asthma | Asthma |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | n/a | $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