Drug interactions
Atenolol-chlorthalidone + Phentolamine
Severity: Moderate
Atenolol-chlorthalidone and Phentolamine: moderate 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
Phentolamine is a nonselective alpha-blocker that causes vasodilation and can cause marked hypotension and reflex tachycardia. Atenolol may blunt the tachycardia while chlorthalidone adds to the pressure lowering, so hypotension can be prolonged.
What this interaction means in plain words
Atenolol-chlorthalidone and Phentolamine 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.
Atenolol-chlorthalidone belongs to Cardiovascular; Phentolamine belongs to Cardiovascular.
Why it happens
Additive hypotensive effects from alpha blockade, beta blockade and diuresis.
What to do
Monitor blood pressure closely during phentolamine use, and be prepared to adjust antihypertensive doses.
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 Atenolol-chlorthalidone and Phentolamine, 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 7 days on the web. No card needed.
Other interactions of Atenolol-chlorthalidone
Other interactions of Phentolamine
Frequently asked questions
Can I take Atenolol-chlorthalidone with Phentolamine?
MediHelp rates the interaction as moderate. Atenolol-chlorthalidone and Phentolamine 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. Phentolamine is a nonselective alpha-blocker that causes vasodilation and can cause marked hypotension and reflex tachycardia. Atenolol may blunt the tachycardia while chlorthalidone adds to the pressure lowering, so hypotension can be prolonged.
How serious is the interaction between Atenolol-chlorthalidone and Phentolamine?
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 blood pressure closely during phentolamine use, and be prepared to adjust antihypertensive doses.
What other medicines interact with Atenolol-chlorthalidone?
MediHelp also lists interactions of Atenolol-chlorthalidone with, for example, Acebutolol, Aldesleukin, Amiodarone. The full list is on the Atenolol-chlorthalidone 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.
