Pharmacology of Nasal Decongestants
Nasal decongestants work by narrowing the blood vessels that are present in the nose. By doing this, it reduces the amount of blood that flows through the nasal cavity so that the swollen tissues shrink in order to allow more air to pass through this area. The majority of decongestants function by increasing the amount of norepinephrine and epinephrine. This is done by stimulating the alpha-adrenergic receptors, which is a class of G protein-couple receptors that are targeted by catecholamines. By doing this, the blood vessels in the nose, throat, and sinuses vasoconstrict and reduces the swelling of the tissues and mucus in these areas. The main ingredients used in decongestants are pseudoephedrine or phenylephrine. Because these ingredients cause vasoconstriction of the blood, people with high blood pressure are not recommended to take this medicine. Other side effects of these chemicals include anxiety, drowsiness, nervousness, and excitability. Common names found in over-the-counter drug stores for decongestants include Sudafed, Afrin, Mucinex, Zicam, and Claritin.
Johnson DA. The Pharmacology of alpha-adrenergic decongestants. 1993, Pharmacotherapy. p. 110s-115s.