title: Treatment failures with levodopa in Parkinsonism.
mesh_terms: D000368:Aged; D000690:Amyotrophic Lateral Sclerosis / Q000188:drug therapy; D002247:Carbon Isotopes; D004295:Dihydroxyphenylalanine / Q000008:administration & dosage / Q000009:adverse effects* / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005069:Evaluation Studies as Topic; D006801:Humans; D008875:Middle Aged; D010300:Parkinson Disease / Q000188:drug therapy* / Q000378:metabolism
chemical_list: D002247:Carbon Isotopes; D004295:Dihydroxyphenylalanine