Ephedrine was first described in western literature in 1888, as a naturally occurring component of the ephedra plant, along with [pseudoephedrine].[A193698] Ephedrine acts as both a direct and indirect sympathomimetic. It is an alpha- and beta-adrenergic rece…

Phenylephrine is an alpha-1 adrenergic receptor agonist used to treat hypotension,[L9416,L9410] dilate the pupil,[L9413] and induce local vasoconstriction.[A187370] The action of phenylephrine, or neo-synephrine, was first described in literature in the 1930s…

Synephrine, also referred to as, p-synephrine, is naturally occurring alkaloid. It is present in approved drug products as neo-synephrine, its m-substituted analog. p-synephrine and m-synephrine are known for their longer acting adrenergic effects compared to…