The rationale in the legal actions of medication involves one of the fundamental pillars in the evaluation of health technologies, which is the effectiveness of the product. However, the adverse drug reaction profile (ADR) is rarely considered in clinical and judicial justifications. This safety indicator is of paramount importance, especially in the case of rare diseases, whose time horizon is prolonged.

OBJECTIVES: to identify the ADR notifications of biological drugs used in rare diseases and involved in legal actions.

METHODS: Descriptive study, which data were obtained from administrative database of Secretaria de Estado da Saúde, São Paulo, Brazil. We analyzed variables related to the number of actions demanded and the amount of drug units for the year 2017; and ADR, deaths and hospitalizations of notifications received from 2005 to 2017. Descriptive statistics were used.

RESULTS: In the analysis of the ADR of the 50 most expensive judicialized drugs, a total of 4,557 notifications were identified, with an average of 122 RAM per patient. Most notifications (76%, 3,462) were due to the use of biological drugs (Eculizumab, Galsulfase, Idursulfase, Betagalsidase, Alfalglicosidase, Laronidase, Miglustate, Translarna, Azacitidine) by patients with rare diseases. Seven hundread and five admissions and 342 deaths were related to these drugs. The death ratio due to ADR reports ranged from zero (Miglustate) to 23.8% (Idursulfase) and was equal to or greater than 10% for Idursulfase, Alfalglicosidase and Laronidase.

CONCLUSIONS: Nine biological drugs, requested by judicialization, were responsible for the most of the ADRs, including deaths. This observation exposes the lack of safety information within the justification of lawsuits.