title: The treatment of neurogenic orthostatic hypotension with 3,4-DL-threo-dihydroxyphenylserine: a randomized, placebo-controlled, crossover trial.
abstract: OBJECTIVE
  To study the therapeutic effect and mechanism of action of 3,4-DL-threodihydroxyphenylserine (DL-DOPS) in neurogenic orthostatic hypotension.
  
  
  METHODS
  The blood pressure (BP) response to an orthostatic challenge on DL-DOPS was compared with that of placebo in a randomized, double-blind, placebo-controlled, crossover trial in 10 patients. The mechanism of action of DOPS was studied by measuring forearm vascular resistance and changes in supine and upright plasma DL-DOPS and norepinephrine levels. The effect of DL-DOPS on the quality of life was determined by questionnaire.
  
  
  RESULTS
  DL-DOPS increased the supine (p<0.001) and upright (p<0.05) systolic blood pressure (SBP) and diastolic blood pressure (DBP) (both p<0.01). The peak SBP on DL-DOPS in the supine position occurred 300 minutes after ingestion of the medication. The increase in BP was accompanied by an increase in plasma levels of norepinephrine and DL-DOPS in both the supine and upright positions after DL-DOPS ingestion (p<0.0001). There was a trend toward improvement in symptoms of orthostatic intolerance.
  
  
  CONCLUSIONS
  DL-DOPS improved features of neurogenic orthostatic hypotension in patients with central and peripheral autonomic nervous system disease. There was an increase in plasma norepinephrine. No major side effects occurred.
authors.affiliation: Department of Neurology, Beth Israel Deaconess Medical Center Harvard Medical School, Boston, MA 02215, USA.
authors.forename: R
authors.initials: R
authors.lastname: Freeman
authors.forename: L
authors.initials: L
authors.lastname: Landsberg
authors.forename: J
authors.initials: J
authors.lastname: Young
mesh_terms: D000328:Adult; D000368:Aged; D000978:Antiparkinson Agents / Q000008:administration & dosage* / Q000009:adverse effects; D001342:Autonomic Nervous System Diseases / Q000188:drug therapy* / Q000209:etiology; D001794:Blood Pressure / Q000187:drug effects; D018592:Cross-Over Studies; D004311:Double-Blind Method; D015103:Droxidopa / Q000008:administration & dosage* / Q000009:adverse effects; D005260:Female; D006801:Humans; D007024:Hypotension, Orthostatic / Q000188:drug therapy* / Q000209:etiology; D008297:Male; D008875:Middle Aged; D019578:Multiple System Atrophy / Q000175:diagnosis / Q000188:drug therapy; D009638:Norepinephrine / Q000097:blood; D018667:Tilt-Table Test; D014655:Vascular Resistance / Q000187:drug effects
chemical_list: D000978:Antiparkinson Agents; D015103:Droxidopa; D009638:Norepinephrine