phentolamine

Disclaimer to the Online Edition

This Manual has been designed for use in the NICU at London Health Sciences Centre (LHSC), London, Ontario, Canada, and represents clinical practice at this institution. The information contained within the Manual may not be applicable to other centres. If users of this Manual are not familiar with a drug, it is recommended that the official monograph be consulted before it is prescribed and administered. Any user of this information is advised that the contributors, Editor and LHSC are not responsible for any errors or omissions, and / or any consequences arising from the use of the information in this Manual

phentolamine

Indication

  • Management of IV extravasations (leakage of an IV fluid out of a vein and into surrounding tissue) due to vasoactive medications (eg. DOBUTamine, DOPamine, EPINEPHrine, norepinephrine, vasopressin)

Dosage Guidelines

  • Prepare a solution of 0.5 mg/mL and administer 1 mL in 5 x 0.2 mL increments SUBCUTANEOSULY to infiltrate area of extravasation.  Dose may be repeated if required.
  • Dose limit: 2.5 mg total
  • Administer within 12 hours of extravasation

Administration

  • SUBCUTANEOUSLY
  • Use a 25 gauge or smaller needle and change needles between each skin entry
  • Draw up 0.2 mL (1 mg phentolamine) and add to 1.8 mL sterile water for injection or sodium chloride 0.9% injection to provide a 0.5 mg/mL solution

Adverse Effects

  • Hypotension, tachycardia, cardiac arrhythmias
  • Vomiting, diarrhea
  • Nasal congestion

Comments

  • Alpha-adrenergic blocking agent that produces peripheral vasodilation, reversing ischemia produced by vasopressor infiltration.
  • Most effective if administered within 1 hour of extravasation but still effective up to 12 hours after
  • Blanching should reverse immediately
  • Monitor site of extravasation closely for skin colour and local perfusion; additional injections of phentolamine may be necessary

Supplied As

  • 5mg/mL, 1mL ampoule

References

LexiComp SickKids, LexiComp Pediatric and Neonatal, Neofax