What is terbutaline commonly used for?

Terbutaline is primarily recognized for its role as a bronchodilator, which means it is used to relax the muscles of the airways, making it easier to breathe. This is particularly beneficial in managing conditions such as asthma and chronic obstructive pulmonary disease (COPD).

While terbutaline can also be utilized in obstetric situations to delay premature labor due to its tocolytic effects (which can lead to the misconception that it is primarily for inducing labor), its main and most recognized application in the pharmacological world is to address airway constriction caused by conditions that affect respiratory function.

In relation to the other options, terbutaline does not have a primary application in lowering blood pressure or treating infections, as those functions are typically managed by other classes of medications. Thus, identifying terbutaline's primary usage as related to airway muscle relaxation aligns accurately with its most common and effective indications in clinical practice.