Decongestants

Nasal congestion is largely a vascular problem. Alpha-adrenergic agonists constrict the venous sinusoids and capacitance vessels in the nasal mucosa, reducing blood volume, mucosal swelling, and the sense of obstruction. They narrow the swollen lining; they do not eradicate a virus, suppress the immune process of allergy, or eliminate a bacterial infection. That distinction predicts both benefit and harm. A topical agent such as oxymetazoline acts mainly where it is sprayed, although some systemic absorption can occur. Oral pseudoephedrine and phenylephrine circulate throughout the body, so the same vasoconstriction that opens the nose may raise blood pressure, increase heart rate, disturb sleep, or worsen urinary retention. A patient may breathe more easily while the underlying illness continues unchanged.