title: Letter: Phenytoin and methadone tolerance.
mesh_terms: D004361:Drug Tolerance; D006801:Humans; D008297:Male; D008691:Methadone / Q000627:therapeutic use*; D008875:Middle Aged; D010672:Phenytoin / Q000009:adverse effects*
chemical_list: D010672:Phenytoin; D008691:Methadone