Drug interactions
Theophylline + Verapamil
Severity: Moderate
Theophylline and Verapamil: moderate interaction.
Last updated Sources: US FDA label
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
Verapamil can increase serum theophylline concentrations modestly. Higher levels may lead to nausea, tachycardia or arrhythmia in sensitive patients.
What this interaction means in plain words
Theophylline and Verapamil 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; Verapamil belongs to Cardiovascular.
Why it happens
Verapamil inhibits hepatic CYP1A2 metabolism of theophylline, reducing its clearance.
What to do
Monitor theophylline levels and signs of toxicity when verapamil is started; reduce theophylline dose if needed.
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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Theophylline and Verapamil, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 14 days on the web. No card needed.
References
- Theophylline (Anhydrous) - FDA drug label (DailyMed) — openFDA / DailyMed
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 Verapamil
- Dofetilide + Verapamil Contraindicated
- Flibanserin + Verapamil Contraindicated
- Lomitapide + Verapamil Contraindicated
- Lonafarnib + Verapamil Contraindicated
- Pimozide + Verapamil Contraindicated
- Acebutolol + Verapamil Major
Frequently asked questions
Can I take Theophylline with Verapamil?
MediHelp rates the interaction as moderate. Theophylline and Verapamil 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. Verapamil can increase serum theophylline concentrations modestly. Higher levels may lead to nausea, tachycardia or arrhythmia in sensitive patients.
How serious is the interaction between Theophylline and Verapamil?
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 levels and signs of toxicity when verapamil is started; reduce theophylline dose if needed.
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.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
