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Non-selective alpha-adrenoceptor antagonist Pregnancy: Use only in emergencies with phaeochromocytoma.

Phentolamine

Brand names: Rogitine

Adult dose

Dose: Phaeochromocytoma crisis: 2–5 mg IV every 5 min; Tissue extravasation: 5–10 mg in 10 mL saline injected locally
Route: IV (crisis) or local infiltration (extravasation)
Frequency: Every 5 min (IV) until BP controlled; single dose (extravasation)
Max: 20 mg IV
Hypertensive crisis from phaeochromocytoma or MAOI interaction: 2–5 mg IV bolus, repeat every 5 min. Cocaine-induced coronary vasospasm/hypertension: 2–5 mg IV. Tissue necrosis prevention after catecholamine extravasation (dopamine, noradrenaline): inject 5–10 mg in 10 mL saline subcutaneously around extravasation site within 12 hours.

Paediatric dose

Dose: 0.05 mg/kg
Route: IV
Frequency: Repeat every 5 min if needed
Max: 5 mg/dose
Concentration: 1 mg/ml
0.05–0.1 mg/kg IV. Specialist paediatric guidance. Phaeochromocytoma in children: extremely rare, specialist management.

Dose adjustments

Renal

No dose adjustment required for acute use.

Hepatic

No dose adjustment for acute use.

Paediatric weight-based calculator

0.05–0.1 mg/kg IV. Specialist paediatric guidance. Phaeochromocytoma in children: extremely rare, specialist management.

Clinical pearls

  • Catecholamine extravasation: inject into infiltrated area as soon as possible — reverses blanching, prevents necrosis
  • Cocaine toxicity: safe (no beta-blockade) — labetalol can cause paradoxical hypertension
  • Phaeochromocytoma surgery: phenoxybenzamine preferred (irreversible) — phentolamine for acute intraoperative crises
  • Pre-anaesthetic check: phentolamine available before phaeochromocytoma surgery

Contraindications

  • Coronary artery disease (reflex tachycardia may cause angina)
  • Hypotension

Side effects

  • Hypotension
  • Reflex tachycardia
  • Nasal congestion
  • GI stimulation (diarrhoea, nausea)

Interactions

  • Sympathomimetics — exaggerated hypotension
  • Antihypertensives — additive hypotension

Monitoring

  • BP every 2–5 min
  • HR
  • Skin integrity (extravasation reversal)

Reference: BNFc; BNF; Endocrine Society Phaeochromocytoma Guidelines. Verify against your local formulary and the latest BNF before prescribing.

Related

Curated clinical cross-links plus same-class fallbacks.

Pathways