What the FDA labels say about taking them together
Ethinyl estradiol/ferrous fumarate/levonorgestrel and theophylline
Ethinyl estradiol/ferrous fumarate/levonorgestrel's FDA label of October 18, 2024 names theophylline in its drug interactions section; the theophylline label PlainMeds reads does not name ethinyl estradiol/ferrous fumarate/levonorgestrel. The ethinyl estradiol/ferrous fumarate/levonorgestrel label: “Contraceptives on Other Drugs Combined oral contraceptives containing EE may inhibit the metabolism of other compounds and increase their plasma concentrations.”
Check it at the source: the ethinyl estradiol/ferrous fumarate/levonorgestrel FDA label on DailyMed (effective October 18, 2024, Xiromed, LLC); the theophylline FDA label on DailyMed (effective March 10, 2026, Strides Pharma Science Limited).
What does the ethinyl estradiol/ferrous fumarate/levonorgestrel label say about theophylline?
Ethinyl estradiol/ferrous fumarate/levonorgestrel label, drug interactionsContraceptives on Other Drugs Combined oral contraceptives containing EE may inhibit the metabolism of other compounds (e.g., cyclosporine, prednisolone, theophylline, tizanidine, and voriconazole) and increase their plasma concentrations.
Source: FDA drug label (Joyeaux), Xiromed, LLC, effective October 18, 2024 (SPL set 655b2c93-cfae-d44f-c128-c816bbd88e45), via openFDA; the full label on DailyMed
What does the theophylline label say about ethinyl estradiol/ferrous fumarate/levonorgestrel?
Theophylline's label (effective March 10, 2026) does not name ethinyl estradiol/ferrous fumarate/levonorgestrel in these sections. A label lists what its studies and reports found; it is not a complete list.
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
| Ethinyl estradiol/ferrous fumarate/levonorgestrel | Theophylline | |
|---|---|---|
| Labeled for | Birth control | Asthma |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | $3.45 per tablet 28 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