Gastric POCUS, 3-Part Episode

Terbutaline is a beta-2-adrenergic receptor agonist that is typically used to treat asthma but has also been used a tocolytic. Beta-agonists relax smooth muscles, including the myometrium. Binding of the receptor increases intracellular levels of cyclic AMP. This increase in intracellular levels of cyclic AMP activates protein kinase, which inactivates myosin light-chain kinase, and decreases myometrium contractility. Common side effects include agitation, restlessness, tremors, arrhythmias, hyperglycemia, and hypokalemia. Pulmonary edema may occur in as great as 5% of patients. Of note, in February 2011 the FDA published an advisory regarding the use of terbutaline to treat pre-term labor. The warning says not to use the oral form of the drug to treat pre-term labor because it does not work, and that injectable terbutaline should be used only in urgent situations and not for more than 48 to 72 hours.