phenoxybenzamine hydrochloride at a glance
Medicine class
Long-acting, non-selective alpha-adrenoceptor blocker
Licensed role
Hypertensive episodes associated with phaeochromocytoma
Administration
Oral hard capsule, taken exactly as prescribed by the specialist team
Key practical issue
May cause dizziness and low blood pressure on standing
What is phenoxybenzamine hydrochloride used for?
The selected product is licensed for:
Controlling hypertensive episodes associated with phaeochromocytoma.
How does phenoxybenzamine hydrochloride work?
Phenoxybenzamine produces a long-lasting blockade of alpha-adrenoceptors. This reduces catecholamine-driven narrowing of blood vessels, lowering vascular resistance and helping control sudden blood-pressure rises caused by phaeochromocytoma.
phenoxybenzamine hydrochloride preparations and strengths
Capsule
Route: Oral
Strengths: 10 mg
How to take phenoxybenzamine hydrochloride
Take the capsule by mouth exactly as prescribed. Treatment is individualised and supervised using blood-pressure response and adverse effects; do not alter it without consulting the specialist team.
Rise slowly from sitting or lying because postural dizziness may occur.
Tell the prescriber if swallowing capsules is difficult; the selected information does not describe an alternative oral formulation.
phenoxybenzamine hydrochloride side effects
Common or expected effects
- Reported effects include dizziness, tiredness, nasal congestion and gastrointestinal upset; the selected product information does not assign frequencies.
- Postural hypotension, compensatory fast heartbeat, small pupils and inhibition of ejaculation can also occur.
Get urgent medical advice
- Fainting or collapse suggesting a substantial fall in blood pressure.
- A sustained very fast or irregular heartbeat, particularly with chest pain, breathlessness or severe weakness.
phenoxybenzamine hydrochloride in pregnancy
Evidence in pregnancy is limited, and the product information says phenoxybenzamine should be used only when essential. It crosses the placenta, and newborn low blood pressure or respiratory depression has been reported.
phenoxybenzamine hydrochloride while breastfeeding
The product information provides no breastfeeding data. A specialist review reports that breastfeeding appears possible, but evidence is limited and individual assessment is appropriate.
phenoxybenzamine hydrochloride interactions
The full medicine list should be reviewed because cardiovascular effects may be altered or intensified.
Beta blockers
For phaeochromocytoma, beta blockade must not precede adequate alpha blockade because this can trigger a dangerous hypertensive crisis.
Other blood-pressure-lowering medicines, including ACE inhibitors and calcium-channel blockers
Combined treatment may increase low blood pressure and postural dizziness, requiring clinical monitoring.
Alpha-sympathomimetics
Alpha-receptor blockade may alter their cardiovascular response, so concurrent use requires specialist consideration.
Common questions about phenoxybenzamine hydrochloride
Answers are fully visible for fast scanning and source review.
What is phenoxybenzamine hydrochloride used for?
The selected product is licensed to control hypertensive episodes associated with phaeochromocytoma.
Is it a selective alpha blocker?
No. It is a non-selective, non-competitive alpha-adrenoceptor blocker with prolonged effects.
Why can it cause dizziness on standing?
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.