What is the mechanism of action (MOA) of terbutaline?

Terbutaline acts as a short-acting beta 2 adrenergic receptor agonist, which means it primarily stimulates the beta 2 receptors found in smooth muscle, particularly in the lungs. This activation leads to bronchodilation, which is the relaxation of the bronchial smooth muscles, facilitating easier breathing.

The specificity of terbutaline for beta 2 receptors is crucial for its therapeutic effects in conditions like asthma and bronchospasm, as it helps to relieve symptoms without significantly increasing heart rate, an effect typically associated with beta 1 receptor stimulation found in the heart. This selectivity is essential in managing respiratory conditions where bronchodilation is needed without adverse cardiovascular effects.

Understanding the mechanism of action provides insight into when and how terbutaline is used in clinical practice, especially in scenarios requiring rapid relief of bronchospasm.