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Non-selective alpha-adrenoceptor antagonist

Phentolamine

Brand names: Rogitine

Phentolamine is a short-acting alpha-adrenoceptor antagonist used to control hypertension in catecholamine excess such as phaeochromocytoma crises and to treat catecholamine extravasation.

Dosing — being independently re-sourced

ClinCalc Pro is rebuilding its dose data from primary open sources — the manufacturer SmPC (eMC), the WHO Model Formulary and other official references — under clinician review. This drug's structured dose is not yet published here. Confirm all doses against the product SmPC and your local formulary before prescribing.

Clinical monograph

How it works

It is a competitive, non-selective alpha-1 and alpha-2 adrenoceptor blocker, producing vasodilatation that lowers blood pressure and counteracts the vasoconstriction caused by extravasated sympathomimetics.

Prescribing in practice

  • Because it can cause abrupt hypotension and reflex tachycardia, administer with continuous blood pressure and cardiac monitoring and have measures to manage haemodynamic swings.
  • In phaeochromocytoma it is used for acute hypertensive episodes and to provide alpha-blockade before any beta-blocker is introduced, never beta-blockade first.
  • Local infiltration is used to reverse the dermal ischaemia of noradrenaline or other vasopressor extravasation.

Monitoring

Monitor blood pressure and heart rate closely and continuously during and after intravenous administration.

Counselling the patient

  • Explain that this medicine rapidly lowers a dangerously high blood pressure or relieves a leaked drug at a drip site.
  • Warn the patient they may feel dizzy, flushed or experience a fast heartbeat.
  • Advise the team to be alert for sudden drops in blood pressure.

Evidence & guidelines

Phentolamine is an established agent for catecholamine-mediated hypertension and for treating vasopressor extravasation, as reflected in its SPC and toxicology references.

Reference: Endocrine Society Phaeochromocytoma Guidelines; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

Pathways