About phenoxybenzamine hydrochloride
Irreversible alpha-adrenergic blocker
Used for
- Controls high blood pressure caused by pheochromocytoma
- Helps manage symptoms while preparing for pheochromocytoma surgery
Usual adult dose
Usually starts at 10 mg twice daily; gradually increased as needed under specialist supervision.
Usual dose in children
Specialist-directed; dosing is individualized by age, weight, and response.
Common side effects
- Dizziness or fainting, especially when standing
- Nasal congestion
- Fast heartbeat
- Fatigue or drowsiness
Important warnings
- Can cause marked low blood pressure; rise slowly from sitting or lying.
- May cause a fast heartbeat or worsen heart problems.
- Use only with specialist monitoring, particularly around surgery.
- Can impair alertness; use caution with driving.
Pregnancy
Safety is not well established; use only when a clinician judges benefits outweigh risks.
Breastfeeding
It is not known whether phenoxybenzamine enters breast milk; breastfeeding safety is uncertain.
Interactions
- Blood-pressure-lowering medicines can increase dizziness or fainting.
- Medicines that raise blood pressure may oppose its effects.
- Alcohol can worsen dizziness and low blood pressure.
- Other medicines causing drowsiness may increase impaired alertness.
AI-generated from general medical knowledge, not from this product's official leaflet. It may be incomplete or out of date. Not medical advice — ask a pharmacist or doctor before making any decision.