Decongestants

Nasal decongestants relieve obstruction by stimulating alpha-adrenergic receptors in the blood vessels of the nasal mucosa. The venous sinusoids constrict, the capacitance of the mucosal vascular bed falls, and swollen tissue occupies less space in the nasal passage. The patient can breathe more freely because the mucosa is less edematous—not because the infection, allergic inflammation, or irritant exposure has been corrected. That distinction determines whether a decongestant is the right treatment. It can temporarily open a blocked nose during a viral upper respiratory infection, but it does not shorten the illness. It may improve airflow while an intranasal corticosteroid treats allergic inflammation, but it is not a substitute for that anti-inflammatory therapy. It can ease pressure related to nasal obstruction during rhinosinusitis, but it does not treat bacterial infection. Route changes the risk profile. Oral pseudoephedrine produces systemic sympathomimetic effects because it circulates throughout the body. Topical agents such as oxymetazoline and xylometazoline act primarily in the nose and generally produce less systemic exposure, but enough absorption can occur to matter in a patient with cardiovascular, ophthalmic, or urinary risk.