Drug interactions
Lisinopril + Phenoxybenzamine
Severity: Moderate
Lisinopril and Phenoxybenzamine: 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
Phenoxybenzamine causes long-lasting alpha-adrenergic blockade and vasodilation, which can compound the blood pressure reduction of lisinopril. Marked orthostatic hypotension may occur, especially at the start of treatment or with dose increases.
What this interaction means in plain words
Lisinopril and Phenoxybenzamine 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
Additive hypotensive effects from irreversible alpha-adrenergic blockade and ACE inhibition.
What to do
Titrate gradually, monitor supine and standing blood pressure, and reduce the lisinopril dose if hypotension develops.
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 Lisinopril
- Aliskiren + Lisinopril Contraindicated
- Lisinopril + Protein a column Contraindicated
- Lisinopril + Sacubitril / valsartan Contraindicated
- Lisinopril + Sacubitril-valsartan Contraindicated
- Amifostine + Lisinopril Major
- Amiloride + Lisinopril Major
Frequently asked questions
Can I take Lisinopril with Phenoxybenzamine?
MediHelp rates the interaction as moderate. Lisinopril and Phenoxybenzamine 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. Phenoxybenzamine causes long-lasting alpha-adrenergic blockade and vasodilation, which can compound the blood pressure reduction of lisinopril. Marked orthostatic hypotension may occur, especially at the start of treatment or with dose increases.
How serious is the interaction between Lisinopril and Phenoxybenzamine?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Titrate gradually, monitor supine and standing blood pressure, and reduce the lisinopril dose if hypotension develops.
What other medicines interact with Lisinopril?
MediHelp also lists interactions of Lisinopril with, for example, Aliskiren, Protein a column, Sacubitril / valsartan. The full list is on the Lisinopril page.
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