Non-selective irreversible α-blocker
Phenoxybenzamine hydrochloride
Brand names: Dibenyline
Adult dose
Dose: Initial 10mg PO BD, increase by 10mg/day to control BP; usual 1–2 mg/kg/day in 2 divided doses
Route: PO
Frequency: BD
Clinical pearls
- Phaeochromocytoma — 10–14 days preoperatively then add β-blocker
- Never start β-blocker first (unopposed α-stimulation)
Contraindications
- History of cerebrovascular accident
- Hypersensitivity
- Postural hypotension
Side effects
- Postural hypotension
- Tachycardia
- Nasal congestion
- Miosis
- Inhibition of ejaculation
Interactions
- Antihypertensives
- Sympathomimetics
Monitoring
- BP (lying/standing)
- HR
Reference: BNF; UK Endocrine Society; https://bnf.nice.org.uk/drugs/phenoxybenzamine-hydrochloride/. Verify against your local formulary and the latest BNF before prescribing.
Related
Curated clinical cross-links plus same-class fallbacks.
Calculators
Pathways
- Diabetic Ketoacidosis (DKA) · JBDS 2013 / Joint British Diabetes Societies; NICE NG17
- Adult Hypoglycaemia (Treated Diabetes) · JBDS-IP (2023): Hospital Management of Hypoglycaemia
- Adrenal Crisis · Society for Endocrinology Emergency Guidance (2024)
- Type 2 Diabetes Management · NICE NG28 2022
- Hyperthyroidism Management · BTA / ETA 2018
- Adrenal Insufficiency · Society of Endocrinology / ESE 2016