Drug interactions
Captopril + Phentolamine
Severity: Moderate
Captopril 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 potent alpha-blocking vasodilator and combining it with captopril can produce marked hypotension, especially with the first doses. Reflex tachycardia and dizziness may occur.
What this interaction means in plain words
Captopril 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.
Captopril belongs to Cardiovascular; Phentolamine belongs to Cardiovascular.
Why it happens
Additive vasodilation from alpha-adrenergic blockade and ACE inhibition.
What to do
Monitor blood pressure closely when phentolamine is given to a patient on captopril, with the patient supine initially. Use lower initial doses and titrate cautiously.
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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Other interactions of Captopril
- Aliskiren + Captopril Contraindicated
- Captopril + Sacubitril / valsartan Contraindicated
- Captopril + Sacubitril-valsartan Contraindicated
- Amifostine + Captopril Major
- Amiloride + Captopril Major
- Amlodipine-hydrochlorothiazide-valsartan + Captopril Major
Other interactions of Phentolamine
Frequently asked questions
Can I take Captopril with Phentolamine?
MediHelp rates the interaction as moderate. Captopril 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 potent alpha-blocking vasodilator and combining it with captopril can produce marked hypotension, especially with the first doses. Reflex tachycardia and dizziness may occur.
How serious is the interaction between Captopril 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 when phentolamine is given to a patient on captopril, with the patient supine initially. Use lower initial doses and titrate cautiously.
What other medicines interact with Captopril?
MediHelp also lists interactions of Captopril with, for example, Aliskiren, Sacubitril / valsartan, Sacubitril-valsartan. The full list is on the Captopril page.
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