title: US drug maker is challenged over decision to force patients to use new version of drug as patent expiry looms.
authors.affiliation: Montreal.
authors.forename: Owen
authors.initials: O
authors.lastname: Dyer
mesh_terms: D004345:Drug Industry / Q000331:legislation & jurisprudence*; D057915:Drug Substitution; D006801:Humans; D008559:Memantine / Q000627:therapeutic use*; D010330:Patents as Topic / Q000331:legislation & jurisprudence*; D057240:Patient Preference; D014481:United States
chemical_list: D008559:Memantine