Drug interactions
Nefazodone + Theophylline
Severity: Moderate
Nefazodone 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
Nefazodone is a strong CYP3A4 inhibitor, but theophylline depends on CYP3A4 only partly, so a clinically relevant increase in levels is possible but not certain. Theophylline toxicity, if it occurs, may include arrhythmias and seizures.
What this interaction means in plain words
Nefazodone 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
Nefazodone inhibits CYP3A4, a secondary route of theophylline metabolism.
What to do
Check theophylline serum concentrations after starting nefazodone and reduce the dose if levels are elevated or toxicity signs appear.
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 Nefazodone 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
- Nefazodone Hydrochloride - 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
Frequently asked questions
Can I take Nefazodone with Theophylline?
MediHelp rates the interaction as moderate. Nefazodone 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. Nefazodone is a strong CYP3A4 inhibitor, but theophylline depends on CYP3A4 only partly, so a clinically relevant increase in levels is possible but not certain. Theophylline toxicity, if it occurs, may include arrhythmias and seizures.
How serious is the interaction between Nefazodone 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: Check theophylline serum concentrations after starting nefazodone and reduce the dose if levels are elevated or toxicity signs appear.
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.
