Drug interactions
Ethinylestradiol + Theophylline
Severity: Moderate
Ethinylestradiol and Theophylline: moderate interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Estrogen-containing contraceptives inhibit CYP1A2 and can reduce theophylline clearance. Levels may rise and cause nausea, tremor, palpitations or seizures.
What this interaction means in plain words
Ethinylestradiol and Theophylline can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Why it happens
Ethinylestradiol inhibits CYP1A2-mediated theophylline metabolism.
What to do
Monitor theophylline concentrations when estrogen contraceptives are started or stopped and reduce the dose if levels are high.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Theophylline
- Riociguat + Theophylline Contraindicated
- Adenosine + Theophylline Major
- Apalutamide + Theophylline Major
- Bupropion + Theophylline Major
- Carvedilol + Theophylline Major
- Cimetidine + Theophylline Major
Frequently asked questions
Can I take Ethinylestradiol with Theophylline?
MediHelp rates the interaction as moderate. Ethinylestradiol and Theophylline can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Estrogen-containing contraceptives inhibit CYP1A2 and can reduce theophylline clearance. Levels may rise and cause nausea, tremor, palpitations or seizures.
How serious is the interaction between Ethinylestradiol and Theophylline?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor theophylline concentrations when estrogen contraceptives are started or stopped and reduce the dose if levels are high.
What other medicines interact with Theophylline?
MediHelp also lists interactions of Theophylline with, for example, Riociguat, Adenosine, Apalutamide. The full list is on the Theophylline page.
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