Decongestants

Nasal obstruction is usually a vascular problem superimposed on an inflamed mucosa. Alpha-adrenergic stimulation constricts the venous sinusoids and capacitance vessels beneath the nasal epithelium. The swollen mucosa becomes thinner, the nasal passage opens, and airflow improves. That mechanism explains both the benefit and the risk. Decongestants shrink tissue; they do not eradicate a virus, kill bacteria, suppress the allergic cascade, or correct a structural obstruction. A patient who feels temporarily better after a spray may still have allergic rhinitis, acute bacterial rhinosinusitis, medication-induced congestion, or a process requiring urgent evaluation. Pseudoephedrine produces a systemic sympathomimetic effect, so its action is not confined to the nose. Phenylephrine is an alpha-adrenergic agonist, but oral phenylephrine undergoes extensive first-pass metabolism. The U.S. Food and Drug Administration proposed removing oral phenylephrine from the OTC monograph in November 2024 because available evidence did not support effectiveness at monograph doses. This was an effectiveness finding, not a newly identified safety crisis; as of August 2026, no final order had removed it, and oral phenylephrine remained available. Topical oxymetazoline acts at the nasal mucosa and generally...