Drug interactions
St john's wort + Theophylline
Severity: Moderate
St john's wort 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
St John's wort induces drug-metabolising enzymes and has been associated with lower theophylline concentrations, with possible loss of asthma control. Stopping the herb may allow levels to rise toward toxicity.
What this interaction means in plain words
St john's wort 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
St John's wort induces hepatic CYP enzymes including CYP1A2 and CYP3A4, increasing theophylline clearance.
What to do
Avoid the combination if possible; if used, monitor theophylline levels and recheck them after the herb is stopped.
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 St john's wort with Theophylline?
MediHelp rates the interaction as moderate. St john's wort 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. St John's wort induces drug-metabolising enzymes and has been associated with lower theophylline concentrations, with possible loss of asthma control. Stopping the herb may allow levels to rise toward toxicity.
How serious is the interaction between St john's wort 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: Avoid the combination if possible; if used, monitor theophylline levels and recheck them after the herb is stopped.
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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