Phenoxybenzamine
Phenoxybenzamine is a long-acting, non-selective alpha-adrenergic blocker used primarily to manage symptoms of pheochromocytoma, a rare tumor of the adrenal glands. It works by irreversibly blocking alpha receptors, causing blood vessel relaxation and lowering blood pressure. This medication is typically used when surgery is not immediately possible or as preoperative preparation.
Phenoxybenzamine is an alpha-blocker used mainly for managing pheochromocytoma by relaxing blood vessels and controlling blood pressure.
Key facts at a glance
- ATC
- C04AX02
- RxNorm
- 8149
- Generic
- Phenoxybenzamine
- Class
- atc-c04
- Brands
- Dibenzyline
- Availability
- rx
- Lactation
- unknown
- Routes
- oral
- Forms
- capsule, solution
- Regions
- US, EU, CN, JP
- Monitoring
- —
This page is for informational purposes only.
Do not use this information to diagnose yourself or to replace a physician's advice. Always consult a qualified healthcare provider before starting, stopping, or changing any medication. If you believe you are experiencing a medical emergency, call your local emergency number immediately.
Primarily used for pheochromocytoma management, including preoperative preparation and long-term control when surgery is not possible. May also be used off-label for conditions involving excessive sympathetic activity such as hyperhidrosis (excessive sweating).
Phenoxybenzamine is a non-selective, irreversible alpha-adrenergic receptor blocker. By blocking alpha-1 and alpha-2 receptors, it prevents catecholamines (like epinephrine and norepinephrine) from causing vasoconstriction, resulting in relaxation of smooth muscle in blood vessels, reduced blood pressure, and improved blood flow.
May cause significant orthostatic hypotension, nasal congestion, and reflex tachycardia. Contraindicated in conditions where hypotension is dangerous. Common side effects include dizziness, drowsiness, and gastrointestinal disturbances. Requires careful dosing titration and blood pressure monitoring. Inform your doctor about all current medications before use, as interactions can occur.
Official drug label
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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 25, 2026. · Read our editorial policy