What is "droxidopa"

n. An antiparkinsonian drug.

Droxidopa ( INN; trade name Northera; also known as L-DOPS, L-threo-dihydroxyphenylserine, L-threo-DOPS and SM-5688) is a synthetic amino acid precursor which acts as a prodrug to the neurotransmitter norepinephrine (noradrenaline). Unlike norepinephrine, droxidopa is capable of crossing the protective blood–brain barrier (BBB).