title: Levodopa and L-tryptophan in parkinsonism.
mesh_terms: D001921:Brain / Q000201:enzymology; D004295:Dihydroxyphenylalanine / Q000009:adverse effects / Q000627:therapeutic use*; D004357:Drug Synergism; D006801:Humans; D010300:Parkinson Disease / Q000188:drug therapy*; D014364:Tryptophan / Q000627:therapeutic use*
chemical_list: D004295:Dihydroxyphenylalanine; D014364:Tryptophan