Drug interactions
Amlodipine + Phenoxybenzamine
Severity: Moderate
Amlodipine 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 is an irreversible alpha blocker that causes marked vasodilation and orthostatic hypotension. Adding amlodipine increases the hypotensive effect, which is often intended in pheochromocytoma but needs careful titration.
What this interaction means in plain words
Amlodipine 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 vasodilation from alpha-adrenergic blockade and calcium channel blockade.
What to do
Monitor supine and standing blood pressure and titrate doses gradually. Reduce one drug if symptomatic hypotension occurs.
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 Amlodipine
- Amifostine + Amlodipine Major
- Amlodipine + Ombitasvir / paritaprevir / ritonavir and dasabuvir Major
- Activated Charcoal + Amlodipine Moderate
- Aldesleukin + Amlodipine Moderate
- Alfuzosin + Amlodipine Moderate
- Amlodipine + Apalutamide Moderate
Frequently asked questions
Can I take Amlodipine with Phenoxybenzamine?
MediHelp rates the interaction as moderate. Amlodipine 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 is an irreversible alpha blocker that causes marked vasodilation and orthostatic hypotension. Adding amlodipine increases the hypotensive effect, which is often intended in pheochromocytoma but needs careful titration.
How serious is the interaction between Amlodipine 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: Monitor supine and standing blood pressure and titrate doses gradually. Reduce one drug if symptomatic hypotension occurs.
What other medicines interact with Amlodipine?
MediHelp also lists interactions of Amlodipine with, for example, Amifostine, Ombitasvir / paritaprevir / ritonavir and dasabuvir, Activated Charcoal. The full list is on the Amlodipine page.
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