Decongestant medications are used to provide relief from a stuffy nose (congestion) or runny nose (rhinorrhea). These symptoms are usually produced due to allergic responses or upper respiratory infections. When congestion or rhinorrhea occur, oral or nasal spray delivery of decongestant medications can provide some relief.

Pseudoephedrine hydrochloride and pseudoephedrine are over-the-counter medications that have potent activity as decongestants. The method of action is similar to those produced by adrenaline for “fight-or-flight” responses, also indicated in it belonging to the amphetamine class of chemicals. This activity produces vasoconstriction (blood vessels become smaller) in the lining of the upper respiratory tract. This, in turn, decreases the production of fluids and mucus by the cells lining the nose, throat and sinuses. The most notable formulation of this medication is Sudafed.

Phenylephrine is marketed as a substitute for pseudoephedrine. The proposed method of action is also by production of an adrenaline response. However, due to more selective targeting of the drug, it is proposed to avoid some common adverse reactions associated with pseudoephedrine. Although phenylephrine was approved in 1976 by the FDA, controversial studies in 2006 and two others in 2009 found insufficient activity for phenylephrine as a decongestant to distinguish it from a placebo. Formulations with phenylephrine include Sudafed PE, PediaCare, Triaminic Thin Strips and Vicks Sinex nasal sprays.

Oxymetazoline is available over the counter in nasal spray and eye drop formulations. Oxymetazoline works quickly, and by acting directly on the affected areas, it typically has fewer side effects than oral decongestion medications. The method of action is also by modifying adrenaline responses, thereby producing vasoconstriction. Oxymetazoline formulations for nasal sprays include Afrin, Dristan, Vicks Sinex and Mucinex Full Force. Visine LR is an eye formulation.