Phenylephrine

General

• Type: Vasopressors
• Dosage Forms:
• Common Trade Names:

Adult Dosing

Dosing

• Start 100-200mcg/min then taper down
  • 40-60mcg/min works for most

Special Populations

• Pregnancy Rating: C
• Lactation: infant risk cannot be ruled out
• Renal Dosing
  • Adult
  • Pediatric
• Hepatic Dosing
  • Adult
  • Pediatric

Contraindications

• Allergy to class/drug

Adverse Reactions

• Baroreceptor-mediated reflex bradycardia
• If extravasates use phentolamine

Pharmacology

• Half-life:
• Metabolism:
• Excretion:
• Mechanism of Action:

Primary Receptor

• α1

Relative Effects

• ↑SVR
• ↓HR (reflex bradycardia)

Notes

• Use with caution in patients with spinal cord injury-related bradycardia
• Useful for treatment of vasodilatory shock when norepinephrine or dopamine have precipitated tachyarrhythmias
• In patients with ↓LV function, unopposed α1 may lead to decreased CO or myocardial ischemia
  • However clinical trials do not support these effects when used in clinically appropriate dose range

Indication

• Neurogenic Shock

References

Authors

Ross Donaldson, Claire, Daniel Ostermayer, Neil Young