propranolol

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.

propranolol

Indication

  • Treatment of hypertension, management of cardiac arrhythmias (such as supraventricular tachycardia) and tetralogy of Fallot cyanotic spells, and used in neonatal thyrotoxicosis

Pharmacology

  • Propranolol is a non-selective beta-adrenergic blocking agent
  • Well absorbed orally, but undergoes a significant first-pass effect (approximately only 30% of a dose reaches the systemic circulation)
  • Essentially all of a given dose is metabolized in the liver
  • Propranolol decreases cardiac output and possesses antiarrhythmic activity (this results from blocking beta1 receptors)
  • In the lung propranolol blocks Beta2 receptors, which increases airway resistance (in the lung Beta2 receptors produce bronchodilation)
  • Propranolol slows the recovery of glucose concentration following the administration of insulin; therefore, propranolol must be used with great care in patients who are susceptible to the development of hypoglycemia

Side Effects

  • Hypoglycemia, hypotension, bradycardia, vomiting, diarrhea, bronchospasm, lethargy, cold extremities

Precautions

  • Use with caution in presence of heart failure, renal or hepatic disease
  • Sudden cessation of propranolol therapy may cause a withdrawal syndrome characterized by a life-threatening hypertensive crisis 1 to 2 days after the drug is discontinued. Therefore, it is essential that therapy be gradually discontinued

Contradictions

  • Hyperactive airway disease, heart block, chronic obstructive lung disease

Dose

  • The 1 mg/mL injection may be diluted with dextrose or saline before administration
Arrhythmias:
  • IV: 0.01 to 0.2 mg/kg by slow push over 10 minutes (physician only). This may be repeated in 10 minutes, and then given every 6 to 8h for maintenance if needed
  • Maximum Single Dose: 1mg
  • May also be given by slow IV infusion
  • PO - 0.17 to 0.7 mg/kg po q8h
  • May increase to 1mg/kg q6h or more as tolerated
Hypertension:
  • PO - 0.17 to 0.7 mg/kg po q8h
  • May increase as tolerated.
Tetralogy Spells:
  • IV - 0.15 to 0.25 mg/kg
  • May repeat every 15 min prn
  • PO - maintenance dose 1 to 2 mg/kg po q6h
Thyrotoxicosis:
  • 0.25 mg/kg po q6h
  • May increase to max of 1 mg/kg po q6h

Supplied As

  • 1 mg/mL, 1 mL vial
  • 1 mg/mL oral suspension, prepared by Pharmacy
References
  1. Roberts, RJ: Drug Therapy in Infants, W.B. Saunders, Toronto, 1984.
  2. Parenteral Drug Administration Guidelines, St. Joseph's Health Centre, London, Ontario.
  3. Gomella TL (Ed): Neonatology - Management, Procedures, On-Call Problems, Diseases, Drugs, 1992, Appleton and Lange, Norwalk, Connecticut.
  4. Bhatt DR, Furman GI, Reber DJ et al: Neonatal Drug Formulary, 1990-1991, 2nd Edition, Fontana, California 92334.