Oxymetazoline is a selective alpha-1 agonist and partial alpha-2 agonist topical decongestant , used in the form of Oxymetazoline hydrochloride , in products such as Afrin , Dristan, Nasivin, Vicks Sinex , Visine L.R., Sudafed OM, and Zicam . more

Oxymetazoline is a selective alpha-1 agonist and partial alpha-2 agonist topical decongestant , used in the form of Oxymetazoline hydrochloride , in products such as Afrin , Dristan, Nasivin, Vicks Sinex , Visine L.R., Sudafed OM, and Zicam . It was developed from Xylometazoline at E.Merck Darmstadt by Fruhstorfer in 1961 (German Patent 1,117,588) and had the distinction of being the nasal decongestant among the on-board medication of Apollo 11. Oxymetazoline is generally available as a 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 .) less