Cardiopulmonary Adverse Effects of Oral and Subcutaneous Terbutaline for Tocolysis

Abstract

Are there differences between the expected or reported adverse reactions associated with terbutaline when administered orally as opposed to the parenteral routes (such as subcutaneously or intravenously)? This is a report on a pulmonary edema and subsequent death of a laboring woman who was treated with a combination of tocolytic agents in an attempt to prolong the gestation. The agents included magnesium sulfate, and subcutaneous and oral terbutaline. The intention is to alert the reader to the cardiovascular risks associated with combining tocolytic agents, and to dispel a pervasive myth that serious adverse reactions do not occur with oral tocolysis (i.e., terbutaline).¹ Until recently, the package insert sheets for both manufacturers of terbutaline restricted the attribution of serious cardiovascular risks to parenteral administration only. The clinical case will be presented, followed by a review of the published literature and the reports on file in the unpublished Food and Drug Administration MedWatch database. Finally, the comparative pharmacokinetics of the oral and parenteral terbutaline is presented to help the reader understand how these adverse events are to be expected with any route of administration of the tocolytic.