Drug interactions
Theophylline + Voxelotor
Severity: Moderate
Theophylline and Voxelotor: 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
Voxelotor inhibits CYP3A4 and may raise exposure to sensitive CYP3A4 substrates. Theophylline has a narrow therapeutic index and is mainly metabolized by CYP1A2, with a smaller CYP3A4 contribution, so the effect is probably modest, but toxicity (arrhythmias, seizures, vomiting) is possible if levels rise.
What this interaction means in plain words
Theophylline and Voxelotor 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.
Theophylline belongs to Respiratory; Voxelotor belongs to Miscellaneous.
Why it happens
Voxelotor inhibits CYP3A4, which may reduce the partial CYP3A4-mediated clearance of theophylline.
What to do
Monitor serum theophylline concentrations and for signs of toxicity when starting or stopping voxelotor. Reduce the theophylline dose if levels rise.
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
Other interactions of Voxelotor
- Amobarbital + Voxelotor Major
- Apalutamide + Voxelotor Major
- Carbamazepine + Voxelotor Major
- Cyclosporin + Voxelotor Major
- Efavirenz + Voxelotor Major
- Enzalutamide + Voxelotor Major
Frequently asked questions
Can I take Theophylline with Voxelotor?
MediHelp rates the interaction as moderate. Theophylline and Voxelotor 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. Voxelotor inhibits CYP3A4 and may raise exposure to sensitive CYP3A4 substrates. Theophylline has a narrow therapeutic index and is mainly metabolized by CYP1A2, with a smaller CYP3A4 contribution, so the effect is probably modest, but toxicity (arrhythmias, seizures, vomiting) is possible if levels rise.
How serious is the interaction between Theophylline and Voxelotor?
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 serum theophylline concentrations and for signs of toxicity when starting or stopping voxelotor. Reduce the theophylline dose if levels rise.
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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