Isoproterenol

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.

Isoproterenol

Indication

  • cardiac stimulant in cardiac arrest, cardiogenic and bacteremic shock
    (Epinephrine is the first line agent in cardiac arrest (administered by the endotracheal tube))

Pharmacology

  • Isoproterenol acts directly on beta 1 and beta 2 adrenergic receptors, it has little, if any, effect on alpha receptors
  • Isoproterenol increases cardiac output via a positive inotropic and chronotropic effect; peripheral resistance is reduced as a result of arterial and arteriolar dilation (beta 2 effect) mainly in skeletal muscle, but also in mesenteric, intestinal and pulmonary vascular beds
  • The net effect is usually a decreased diastolic pressure (a result of vasodilation) and an increase in systolic pressure (a result of increased cardiac output)

Side Effects

  • Flushing, vomiting, tachycardia, weakness, sweating, profound hypotension
  • Overdose: arrhythmias, elevation followed by a fall in blood pressure, cardiac arrest
  • In hypoxia, ventricular arrhythmias can occur even in recommended dosage range
  • restlessness, excitement

Precautions

  • Monitor ECG, heart rate, blood pressure, urine volume

Dose

  • 0.05 to 0.5 mcg/kg/min continuous IV infusion (Maximum 2 mcg/kg/min)
  • Concentration of the IV infusion should be 1-5 mcg/mL

Supplied As

1: 5,000 (0.2 mg/ml) ampoule

References
  1. McEvoy G K (ed): AHFS Drug Information, American Society of Hospital Pharmacists, 1991.
  2. Roberts, RJ: Drug Therapy in Infants, W.B. Saunders, Toronto, 1984.
  3. Taeusch WH Ballard RA and Avery ME (ed): Schaffer and Avery's Diseases of the Newborn, WB Saunders Co, Toronto, Ontario; 6th Edition, 1991.
  4. Young TE and Mangum OB: Neofax - A Manual of Drugs Used in Neonatal Care, Columbus, Ohio: Ross Laboratories, 1992.