Aspirina, ticlopidina e clopidogrel nas síndromes isquêmicas miocárdicas instáveis com e sem supradesnível do segmento ST / Aspirin, ticlopidine and clopidogrel in acute coronary syndromes

RESUMO

Os antiplaquetários representam importante estratégia de tratamento para pacientes com síndromes coronárias agudas.Em decorrência do importante papel da aspirina e das robustas evidências de benefício na doença isquêmica do coração, seu emprego passou a abranger praticamente todas as modalidades de tratamento clínico, procedimentos percutâneos invasivos e intervenções cirúrgicas relacionadas à doença arterial coronária. Porém, apesar dos benefícios decorrentes do uso de aspirina, pacientes com síndrome coronáriana aguda ainda apresentam risco considerável de eventos cardiovasculares indesejáveis a curto prazo, como morte, reinfarto e acidente vascular cerebral. Derivados tienopiridínicos como ticlopidina e clopidogrel agregaram benefícios ao tratamento desses pacientes, agindo de maneira sinérgica à aspirina. Com perfil mais seguro e menos efeitos adversos comparativamente à ticlopidina, o clopidogrel foi testado em estudos clínicos controlados, randopmizados conduzidos internacionalmente, envolvendo grande número de pacientes com síndromes coronárias agudas com indiscutível demonstração de benefícios em ampla gama de situações clínicas. Características farmacológicas...

ABSTRACT

Antiplatelet agents represent an important treatment strategy for patients with acute coronary syndromes. Due to the important role of aspirin and robust evidence of benefit in ischemic heart disease, its use was expanded to include virtually all forms of medical treatment, invasive percutaneous procedures and surgical interventions related to coronary artery disease. But despite the benefits of aspirin, patients with acute coronary syndromes still present considerable risk of short and long-term adverse cardiovascular events, such as death, reinfarction and stroke. Thienopyridine derivatives like ticlopidine and clopidogrel have added benefits to the treatment of these patients acting in synergism with aspirin. With a safer profile and less adverse effects as compared to ticlopidine, clopidogrel has been tested in controlled, randomized, international clinical trials involving a large number of patients with acute coronary syndromes clearly showing to be beneficial in a wide range of clinical situations. Pharmacological characteristics of clopidogrel as time of onset, need of metabolization for a therapeutic effect and irreversible platelet receptors blockade still limit its use, as well as the possibility of gene polymorphism of cytochrome P450, drug interactions and resistance to its effect and to aspirin. This review briefly addresses the main scientific studies evaluating the effects of these drugs in acute coronary syndromes with emphasis on new knowledge about aspirin and clopidogrel, drug interaction, use of genetic and platelet adhesiveness tests and the impact of recent scientific studies in the daily practice.