<p>Nasal congestion is caused by various etiologies, such as rhinosinusitis and allergic or non-allergic rhinitis, leading to congestion of the venous sinusoids lining the nasal mucosa. Activation of &alpha;-adrenergic receptors leads to vasoconstriction of the blood vessels of the nasal mucosa and resumption of nasal airflow. As the most abundantly expressed in the human nasal mucosa, &alpha;1A- and &alpha;2B-adrenoceptors may play the most important role in vasoconstriction of the human nasal mucosa. Xylometazoline is a more selective agonist at &alpha;2B-adrenoceptors, with affinity at &alpha;1A-, &alpha;2A-, &alpha;2C-, &alpha;1B-, and &alpha;1D-adrenoceptors. Xylometazoline decreases nasal resistance during inspiration and expiration and increases the volume of nasal airflow. Compared to oxymetazoline, another imidazoline nasal decongestant, xylometazoline had a slightly faster onset of action although they had a similar duration of action. In one study, subjects with nasal congestion reported relief of earache and sore throat in addition to nasal decongestion: it is speculated that oxymetazoline mediates this effect by causing vasoconstriction of the nasal mucosa that contains the venous sinuses and nasal decongestion allows breathing through the nose, providing relief from sore throat caused by mouth breathing that dries and irritates the throat.</p>