RESUMO
Las plaquetas juegan un rol importante en la fisiopatología de la trombosis coronaria. Los antagonistas de los receptores de ADP actúan en la superficie de las plaquetas inhibiendo la activación y agregación plaquetaria en pacientes que tienen una ruptura espontanea o cuando se realiza una intervención coronaria percutanea atenuando el inicio de una trombosis aguda. La adicion del clopidogrel al acido acetil salicilico fue un cambio revolucionario en el tratamiento del Sindrome Coronario Agudo. Sin embargo, a pesar de los resultados obtenidos con esta asociación, el clopidogrel ha mostrado tener ciertas limitaciones incluyendo una variabilidad en el efecto inhibitorio antiplaquetario, que han sido asociados con eventos adversos de tipo trombotico. Por esta razón se han realizado nuevos estudios de antagonistas de los receptores P2Y12 siendo los mas importantes los realizados con el Prasugrel y Ticagrelor, que demostraron mayor inhibición plaquetaria que el clopidogrel. Sin embargo esta potente acción inhibitoria viene asociado con un incremento en las complicaciones hemorrágicas, siendo necesario una adecuada estratificación de riesgo trombotico /y o hemorrágico en cada paciente. El éxito en la terapia bloqueadora de los receptores P2Y12 han reducido el uso de los Inhibidores de Glicoproteina IIB/IIIA, usandose en forma complementaria en pacientes con alto riesgo trombotico o en pacientes cuya angiografía evidencia trombos residuales.
Assuntos
Humanos , Inibidores da Agregação Plaquetária/história , Inibidores da Agregação Plaquetária/uso terapêutico , Plaquetas , Trombose Coronária/terapiaRESUMO
Even at the beginning of the next millennium, aspirin will still offer surprises. Its relatively young pharmacological history compares with the early use of salicylate-containing plants since antiquity. The Assyrians and the Egyptians were aware of the analgesic effects of a decoction of myrtle or willow leaves for joint pains. Hippocrates recommended chewing willow leaves for analgesia in childbirth and the Reverend Edward Stones is acknowledged as the first person to scientifically define the beneficial antipyretic effects of willow bark. At the beginning of the 19th century salicin was extracted from willow bark and purified. Although a French chemist, Charles Gerhardt, was the first to synthesize aspirin in a crude form, the compound was ignored, and later studied by Felix Hoffmann. He reportedly tested the rediscovered agent on himself and on his father, who suffered from chronic arthritis--a legend was born and Bayer Laboratories rose to the heights of the pharmacological world. First used for its potent analgesic, antipyretic and anti-inflammatory properties, aspirin was successfully used as an antithrombotic agent. Sir John Vane elucidated aspirin's active mechanism as an inhibitor of prostaglandin synthetase and received the Nobel Price in Medicine for this work in 1982. Two isoform of cyclooxygenase (COX-1 and COX-2) have now been identified, each possessing similar activities, but differing in characteristic tissue expression. The cox enzyme is now a target of drug interventions against the inflammatory process. After two centuries of evaluation, aspirin remains topical, and new therapeutic indications are increasingly being studied.