Drug interactions
Pentoxifylline + Theophylline
Severity: Moderate
Pentoxifylline and Theophylline: 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
Pentoxifylline is a xanthine derivative and has been reported to raise theophylline concentrations. This can cause theophylline toxicity such as nausea, tremor, tachycardia or arrhythmia.
What this interaction means in plain words
Pentoxifylline 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.
Pentoxifylline belongs to Cardiovascular; Theophylline belongs to Respiratory.
Why it happens
Pentoxifylline may reduce theophylline metabolism, with additive xanthine pharmacodynamic effects.
What to do
Monitor theophylline serum concentrations and for signs of toxicity when the two are combined, and 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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Pentoxifylline and Theophylline, 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 Pentoxifylline
- Amifostine + Pentoxifylline Moderate
- Fluoxetine + Pentoxifylline Moderate
- Fluvoxamine + Pentoxifylline Moderate
- Insulin degludec / insulin aspart + Pentoxifylline Moderate
- Methoxsalen + Pentoxifylline Moderate
- Mexiletine + Pentoxifylline Moderate
Frequently asked questions
Can I take Pentoxifylline with Theophylline?
MediHelp rates the interaction as moderate. Pentoxifylline 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. Pentoxifylline is a xanthine derivative and has been reported to raise theophylline concentrations. This can cause theophylline toxicity such as nausea, tremor, tachycardia or arrhythmia.
How serious is the interaction between Pentoxifylline 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 serum concentrations and for signs of toxicity when the two are combined, and 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.
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.
