Terbutaline is known for which of the following effects?

Terbutaline is a beta-agonist commonly used in obstetric practice, particularly for its tocolytic properties, meaning it helps to inhibit uterine contractions. As a beta-2 adrenergic agonist, its primary function is to relax smooth muscle, including that of the uterus, thereby reducing contractions during preterm labor.

One of the known side effects of terbutaline is an increased heart rate, which occurs due to its stimulatory effect on beta-1 adrenergic receptors in the heart. This results in a state of tachycardia, where the heart beats faster, which can be a concern in maternal and fetal health monitoring.

In comparison, decreased heart rate is not an effect associated with terbutaline; rather, it tends to elevate heart rate. Additionally, it directly decreases uterine contractions, making the choice related to uterine contraction incorrect. Regarding hypocalcemia, it does not relate to the pharmacological effects of terbutaline.

Thus, the increase in heart rate stands out as a significant and well-documented effect of terbutaline therapy, particularly relevant for healthcare providers to recognize when administering this medication.