Phentolamine

Administration

  • Type: [[α1 Blocker]]; Antidote, Extravasation; Antihypertensive
  • Routes of Administration: IV, IM
  • Common Trade Names: OraVerse

Adult Dosing

  • Pheochromocytomectomy adjunct: 5mg IM/IV q2-4h PRN
    • Start: 1-2h preop
  • Extravasation (norepinephrine-associated): 5-10mg injected into affected area x1
    • Start: within 12h of extravasation

Pediatric Dosing

  • Pheochromocytomectomy adjunct: 1mg IM/IV q2-4h PRN
    • Start: 1-2h preop

Special Populations

Renal Dosing

  • No dosing adjustments

Hepatic Dosing

  • No dosing adjustments

Contraindications

  • Hypersensitivity to phentolamine or components
  • MI
  • CAD
  • Angina
  • Caution if PUD

Adverse Reactions

Serious

Common

Pharmacology

  • Half-life: 19 minutes
  • Metabolism: Urine
  • Excretion: CYP450

Mechanism of Action

References

<Epocrates, UpToDate>