 phenylephrine is a selective Î±1-adrenergic receptor agonist used primarily as a decongestant, as an agent to dilate the pupil, and to increase blood pressure. phenylephrine is marketed as an alternative for the decongestant pseudoephedrine, though clinical studies suggest that phenylephrine is less effective than pseudoephedrine and not more effective than placebo. ==medical uses== ===decongestant=== phenylephrine is used as a decongestant sold as an oral medicine or as a nasal spray. it is a common ingredient in over-the-counter decongestants. other decongestants include oxymetazoline (brand name: afrin) and pseudoephedrine (brand name: sudafed) oral phenylephrine is extensively metabolized by monoamine oxidase,http://www.drugbank.ca/drugs/db00388#identification an enzyme that is present on the outside of cells, throughout the body. compared to intravenous pseudoephedrine, 
Alcohols Alpha-adrenergic_agonists Amines Cardiac_stimulants Phenethylamines Phenols Rhinology Topical_decongestants Vasoconstrictors