Neuropathic low blood pressure: Droxidopa
Patients suffering from small fibre neuropathy sometimes also suffer from difficult to treat low bloodpressure. In the Orient there is a registered drug for this dindication: L-DOPS (L-threo-dihydroxyphenylserine; Droxidopa; SM-5688). Droxidopa is a synthetic amino acid precursor which acts as a prodrug to the neurotransmitters norepinephrine (noradrenaline) and epinephrine (adrenaline). Unlike norepinephrine and epinephrine themselves, L-DOPS is capable of crossing the protective blood-brain barrier (BBB).
L-DOPS was developed by Sumitomo Pharmaceuticals under the trade name Droxidopa for the treatment of hypotension, and the drug has been used in Japan and some surrounding Asian areas for these indications since 1989. Following a merge with Dainippon Pharmaceuticals in 2006, Dainippon Sumitomo Pharma licensed L-DOPS to Chelsea Therapeutics to develop and market it worldwide except in Japan, Korea, China, and Taiwan.
Though droxidopa has been used in Asia already for some time, it is also currently in clinical trials at the phase III point in the United States (U.S.), Canada, Australia, and throughout Europe. 
Provided L-DOPS successfully completes clinical trials, it could have been approved as early as 2009, which did not yet happen in 2010.
Contamination of the drug by dihydroxyphenylacetaldehyde is currently an issue. 
Chelsea Therapeutics obtained orphan drug status (ODS) for L-DOPS in the U.S.
(Some Details from Wikipedia)
April 2010, Jan M. Keppel Hesselink, MD, PhD