title: DL-threo-3,4-dihydroxyphenylserine for freezing symptom in parkinsonism.
mesh_terms: D000368:Aged; D000978:Antiparkinson Agents; D001812:Blood-Brain Barrier; D002262:Carboxy-Lyases / Q000037:antagonists & inhibitors; D004298:Dopamine / Q000378:metabolism; D015103:Droxidopa / Q000008:administration & dosage / Q000378:metabolism / Q000627:therapeutic use*; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D007980:Levodopa / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D009638:Norepinephrine / Q000378:metabolism; D010300:Parkinson Disease / Q000188:drug therapy*; D012694:Serine / Q000031:analogs & derivatives*
chemical_list: D000978:Antiparkinson Agents; D012694:Serine; D007980:Levodopa; D002262:Carboxy-Lyases; D015103:Droxidopa; D004298:Dopamine; D009638:Norepinephrine