Neonatal Intensive Care UnitChildren's Hospital


Disclaimer to the On-line 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.



  • to restore sinus rhythm in infants who have supraventricular tachycardia


  • phenylephrine acts predominantly on the systemic vasculature (alpha receptors)to produce vasoconstriction, resulting in increased systolic and diastolic blood pressure
  • its main effect on the heart is bradycardia, which results from increased vagal activity resulting as a reflex from the increase in blood pressure

Side Effects

  • hypertension
  • can cause severe peripheral and visceral vasoconstriction (eg. kidney, resulting in decreased renal perfusion and decreased urine output)
  • can cause severe bradycardia
  • may cause restlessness, tremor, respiratory distress, pallor, or blanching of the skin

    Treatment of Side Effects
    • severe hypertension can be treated with phentolamine 100 mcg/kg (0.1 mg/kg) IV push, by physician ONLY
    • severe bradycardia can be treated with atropine 10 mcg/kg (0.01 mg/kg) IV push, by physician ONLY


  • for supraventricular tachycardia: 10 mcg/kg (0.01 mg/kg) IV push over 10-20 seconds by physician ONLY; may repeat x 1


  1. McEvoy G K (ed): AHFS Drug Information, American Society of Hospital Pharmacists, 1991.
  2. Pagliaro LA and Pagliaro AM (ed): Problems in Pediatric Drug Therapy, 1987, Drug Intelligence Publ Inc, Hamilton, Illinois.
  3. Garson A Jr: "Supraventricular Tachycardia". In Gillettee PC and Garson A Jr (Eds): Pediatric Cardiac Dysrhythmias, Grune and Stratton, New York, 1981.
  4. Personal Communication with Herschel Rosenberg, MD, Cardiology, Children's Hospital of Western Ontario, 5 April 1989.

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