Aspectos práticos no diagnóstico e manejo das reações de hipersensibilidade a fármacos

As reacoes de hipersensibilidade a farmacos (RHF) podem ser de natureza alergica ou nao alergica, e correspondem a aproximadamente 15% de todas as reacoes adversas a farmacos (RAF). As reacoes alergicas sao mediadas por mecanismo imune, nao previsiveis, podendo ser grave se ate mesmo fatais, ou requererem internacoes hospitalares prolongadas. Erros na classificacao das RHF ocorrem com frequencia, principalmente quando o diagnostico e baseado apenas na historia clinica (superdiagnostico) ou quando as reacoes nao sao documentadas de maneira apropriada (subdiagnostico). O diagnostico inadequado pode levar a exclusao desnecessaria, com diminuicao das opcoes terapeuticas, e ao uso de farmacos alternativos ineficazes e/ou de custo elevado. Os grupos de farmacos mais comumente envolvidos em reacoes de hipersensibilidade sao os betalactâmicos e os anti-inflamatorios nao esteroidais (AINEs). Consensos atuais preconizam uma investigacao diagnostica sistematizada das RHF atraves da realizacao de testes cutâneos, laboratoriais e testes de provocacao, direcionados por uma historia clinica detalhada. O objetivo do presente estudo e abordar aspectos praticos do diagnostico e manejo das reacoes de hipersensibilidade a farmacos, com enfase aos betalactâmicos e AINEs, de acordo com os estudos e consensos atuais... Drug hypersensitivity reactions (DHRs) may be classified as allergic or non-allergic, and they correspond to approximately 15% of all adverse drug reactions (ADRs). Allergic reactions are non-predictable and mediated by immune mechanisms; they may be severe and even life threatening, or may require prolonged hospitalization. Misclassification of DHRs is frequent, especially when diagnosis is based only on medical history (overdiagnosis), or when reactions are not properly documented (underdiagnosis). An incorrect diagnosis may lead to unnecessary exclusion of drugs, reducing treatment options, as well as to the use of alternative ineffective and/or expensive medications. Beta-lactam and non-steroidal anti-inflammatory drugs are the groups most commonly involved in DHRs. Current guidelines recommend a systematic diagnostic investigation of DHRs using skin, laboratory, and provocations tests, guided by a detailed medical history. The aim of this study was to address practical aspects of the diagnosis and management of DHRs, with a focus on beta-lactam and non-steroidal anti-inflammatory drugs, according to current studies and consensuses...