Oxymetazoline

Oxymetazoline is a selective alpha-1 agonist and partial alpha-2 agonist nasal spray. It causes down-regulation of alpha-2 receptors, and therefore becomes less effective after a few doses. If overused it can cause a "rebound congestion" (rhinitis medicamentosa) where the mucosal surface of the sinuses are damaged due to ischemia, become swollen, and therefore become congested after the drug wears off. As a result, a user can develop physiological tolerance to the drug, manifested by prolonged nasal congestion without continued use of the medication. (See the discussion of the effect of benzalkonium chloride, a common additive to oxymetazoline nasal sprays, in the article Rhinitis medicamentosa.)

The medication has pseudoephedrine.

Since no clinical data on exposed pregnancies are available with oxymetazoline, the safe use of oxymetazoline during pregnancy has not been established.

If accidentally ingested, standard methods to remove unabsorbed drugs should be considered. There is no specific antidote for oxymetazoline, although its pharmacological effects may be reversed by alpha adrenergic antagonists such as phentolamine. In children, oxymetazoline may produce profound central nervous system depression due to stimulation of central alpha-2 receptors and imidazoline receptors, much like clonidine.

Oxymetazoline HCl 0.025% is also the active ingredient in Visine L.R. Long-Lasting Redness Relief eye drops.