Name: PHENTOLAMINE (RogitineR)
Classification: alpha antagonist; vasodilator
  • alpha blockade in pheochromocytoma (used with a beta blocker)
  • antidote for extravasation of alpha stimulants
  • antihypertensive agent
  • afterload reduction
  • useful to treat hypertension in MAO-I overdose
Dose:
  • Bolus dose: 
    • 1-5mg IV direct
  • Infusion
    • 0.1mg - 2mg/min (start at lowest dose and titrate to blood pressure). Doses up to 2 mg/min have been used for severe hypertension.
  • Antidote for vasoconstrictor extravasation: 
    • 5-15mg in 10 mL NS infiltrated into the area of extravasation as soon as possible; may be effective up to 12 hours post extravasation of vasoconstrictor
    • administer initial dose into interstitial catheter prior to removal to direct phentolamine into area of infiltration
    • anticipate need for increased sympathomimetic therapy and/or volume therapy
Administration: IV Infusion:
300mg/500mL D5W, NS RL
  • should be weaned off
  • treat hypovolemia concurrently with initiation of drug therapy
  • For pheochromocytoma blockade - initiate phentolamine prior to commencing beta blockade; beta blockade may increase peripheral vasoconstriction and worsen hypertension
Adverse Effects:
  • hypotension
  • hypovolemia
  • tachycardias
  • arrhythmias
  • increased gastric acid secretion
  • tachyphylaxis may occur 
Drug Interactions:
  • phentolamine + alpha adrenergic agents = decreased alpha effects
Monitoring Therapy:
  • BP
  • HR, ECG
  • urine output
  • cardiac index
  • PWP
  • SVRI, PVRI
  • arterial lactate
CCTC Protocol:
  • May be administered by IV infusion or IV direct by an approved nurse in CCTC.
  • May be titrated by an approved nurse in CCTC.
  • Preferable to administer via a central line.
  • Continuous infusion must be administered via an infusion pump.
  • Should not be infused via proximal injectate port (blue) of the Swan Ganz catheter.
  • Patient requires placement of an arterial line to monitor BP.


Lynne Kelly, Pharmacist, CCTC
Brenda Morgan, Clinical Nurse Specialist, CCTC
Last Update: January 12, 2017

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Last Updated January 12, 2017 | © 2007, LHSC, London Ontario Canada