Drug interactions
Peginterferon alfa 2a + Theophylline
Severity: Moderate
Peginterferon alfa 2a 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
Peginterferon alfa-2a can raise serum theophylline concentrations. Reduced theophylline clearance may lead to nausea, tachycardia, tremor, arrhythmias or seizures in susceptible patients.
What this interaction means in plain words
Peginterferon alfa 2a 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.
Peginterferon alfa 2a belongs to Anti Virals; Theophylline belongs to Respiratory.
Why it happens
Interferon alfa inhibits CYP1A2, the main enzyme responsible for theophylline metabolism, reducing its clearance.
What to do
Measure theophylline concentrations before and during peginterferon therapy and reduce the theophylline dose as needed. Monitor for signs of toxicity.
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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References
- Pegasys - 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 Peginterferon alfa 2a
Frequently asked questions
Can I take Peginterferon alfa 2a with Theophylline?
MediHelp rates the interaction as moderate. Peginterferon alfa 2a 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. Peginterferon alfa-2a can raise serum theophylline concentrations. Reduced theophylline clearance may lead to nausea, tachycardia, tremor, arrhythmias or seizures in susceptible patients.
How serious is the interaction between Peginterferon alfa 2a 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: Measure theophylline concentrations before and during peginterferon therapy and reduce the theophylline dose as needed. Monitor for signs of toxicity.
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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