Drug interactions
Penbutolol + Theophylline
Severity: Major
Penbutolol and Theophylline: major 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
Beta blockers oppose the bronchodilating effect of theophylline and can provoke bronchospasm in susceptible patients. Nonselective agents may also reduce theophylline clearance, raising levels and the risk of toxicity.
What this interaction means in plain words
Penbutolol and Theophylline can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Why it happens
Pharmacodynamic antagonism at beta-2 receptors, plus possible inhibition of theophylline metabolism by nonselective beta blockers.
What to do
Avoid nonselective beta blockers in patients with asthma or COPD where possible; if essential, use a cardioselective agent and monitor theophylline levels and respiratory status.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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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
Frequently asked questions
Can I take Penbutolol with Theophylline?
MediHelp rates the interaction as major. Penbutolol and Theophylline can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Beta blockers oppose the bronchodilating effect of theophylline and can provoke bronchospasm in susceptible patients. Nonselective agents may also reduce theophylline clearance, raising levels and the risk of toxicity.
How serious is the interaction between Penbutolol and Theophylline?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid nonselective beta blockers in patients with asthma or COPD where possible; if essential, use a cardioselective agent and monitor theophylline levels and respiratory status.
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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