title: [Levothyroxine and the problem of interchangeability of drugs with narrow therapeutic index].
abstract: The exchange of a prescribed drug by other similar, by generic products and even by custom products has become common practice in our country, often ignoring basic tenets of bioequivalence, interchangeability, stability and characteristics of the pharmaceutical compounds. In the case of drugs of narrow therapeutic index, such as levothyroxine, these problems are intensified, putting the effectiveness of treatment and patient health at serious risk. We review the pertinent legislation, emphasizing the characteristics of levothyroxine and adverse effects that limit the interchangeability of the compound.
authors.affiliation: Departamento de Tireoide da Sociedade Brasileira de Endocrinologia e Metabologia, Universidade Estadual de Campinas, SP, Brasil. ward@unicamp.br
authors.forename: Laura Sterian
authors.initials: LS
authors.lastname: Ward
mesh_terms: D016907:Adverse Drug Reaction Reporting Systems; D001938:Brazil; D017277:Drug Approval / Q000331:legislation & jurisprudence*; D057915:Drug Substitution / Q000009:adverse effects; D016568:Drugs, Generic / Q000009:adverse effects / Q000493:pharmacokinetics*; D006801:Humans; D013810:Therapeutic Equivalency; D013963:Thyroid Hormones / Q000502:physiology; D013974:Thyroxine / Q000009:adverse effects / Q000493:pharmacokinetics*
chemical_list: D016568:Drugs, Generic; D013963:Thyroid Hormones; D013974:Thyroxine