New antiplatelet drugs

Antiplatelet drugs are used in a wide range of disorders, either as sole agents or as adjuncts to other therapies. Aspirin has been shown to be clinically effective in a number of ischaemic conditions and has been in use for many years. The newer agents, ticlopidine and clopidogrel (which are thought to inhibit ADP-mediated platelet reactions) are also effective and may prove to be superior to aspirin in certain indications. However, ticlopidine in particular has a different spectrum of side-effects, which may eventually limit its widespread use. The Gp IIb/IIIa antagonists have been most extensively investigated in the acute coronary syndromes, and shown to significantly improve outcome. Most of these studies have utilized agents which need to be given parenterally, and subsequently oral compounds are currently being developed. A number of other antiplatelet drugs such as prostacyclin and its analogues, as well as thromboxane inhibitors have been studied over the years, but overall they have failed to demonstrate any real clinical advantage.