vorapaxar and terutroban

Antiplatelet agents are a cornerstone in the treatment of acute arterial thrombotic events and in the prevention of thrombus formation. However, existing antiplatelet agents (mainly aspirin, the combination of aspirin and dipyridamole and clopidogrel) reduce the risk of vascular events only by about one quarter compared with placebo. As a consequence, more efficacious antiplatelet therapies with a reduced bleeding risk are needed. We give an overview of several new antiplatelet agents that are currently investigated in secondary stroke prevention: adenosine 5'-diphosphonate receptor antagonists, cilostazol, sarpogrelate, terutroban and SCH 530348. There are unique features in secondary stroke prevention that have to be taken into account: ischaemic stroke is a heterogeneous disease caused by multiple aetiologies and the blood-brain barrier is disturbed after stroke which may result in a higher intracerebral bleeding risk. Several small randomized trials indicated that the combination of aspirin and clopidogrel might be superior to antiplatelet monotherapy in the acute and early post-ischaemic phase. There is an ongoing debate about antiplatelet resistance. Decreasing response to aspirin is correlated independently with an increased risk of cardiovascular events. However, there is still no evidence from randomized trials linking aspirin resistance and recurrent ischaemic events. Similarly, randomized trials have not demonstrated a clinical significantly decreased antiplatelet effect by the concomitant use of clopidogrel and proton pump inhibitors. Nevertheless, a routine use of this drug combination is not recommended.

Topics: Aspirin; Blood-Brain Barrier; Cilostazol; Clopidogrel; Dipyridamole; Drug Interactions; Drug Therapy, Combination; Humans; Lactones; Naphthalenes; Platelet Aggregation Inhibitors; Propionates; Pyridines; Randomized Controlled Trials as Topic; Secondary Prevention; Stroke; Succinates; Tetrazoles; Thrombosis; Ticlopidine

Antiplatelet therapy remains a cornerstone of modern management of atherothrombotic vascular disease. For many years, aspirin has been the mainstay of initial antiplatelet drug management in coronary heart disease, while the need for inhibition of other platelet activation pathways has led to the development of various other antiplatelet drugs, such as clopidogrel. An improved understanding of the underlying mechanisms involved in thrombogenesis has paved the way for further development of newer antiplatelet drug therapies. Various clinical studies have probed the effectiveness and risk profile of the newer antiplatelet drugs, such as prasugrel, in comparison with currently available drugs. Some newer agents such as prasugrel are close to being approved for clinical use, whereas other agents such as cangrelor and AZD6140 are in phase 3 clinical trials. New drug classes, such as the thromboxane receptor antagonists (such as NCX-4016 and S18886), as well as platelet adhesion antagonists and thrombin receptor antagonists are similarly being evaluated for their efficacy and risk profile in phase I and II trials.

Topics: Adenosine; Adenosine Monophosphate; Aspirin; Clinical Trials as Topic; Clopidogrel; Coronary Artery Disease; Drug Design; Humans; Imines; Lactones; Naphthalenes; Piperazines; Platelet Aggregation Inhibitors; Prasugrel Hydrochloride; Propionates; Purinergic P2 Receptor Antagonists; Pyridines; Thiophenes; Ticagrelor; Ticlopidine

Despite recent advances in the treatment of acute coronary syndromes (ACS), including dual antiplatelet therapy with aspirin and a thienopyridine during the acute phase and for secondary prevention, this condition remains a leading cause of morbidity and mortality. The limitations of the currently available antiplatelet agents have triggered the development of newer drugs. In this review we summarize the mechanisms of actions and results of current clinical trials of novel antiplatelet agents. These include prasugrel, a thienopyridine prodrug which has a mechanism similar to that of clopidogrel but superior pharmacokinetic features; ticagrelor, a non-thienopyridine that binds reversibly to the platelet P2Y(12) receptor; cangrelor, an intravenously administered analog of ticagrelor; the thrombin receptor antagonist SCH 53048; and terutroban (S18886), a thromboxane A(2) receptor inhibitor.

Topics: Acute Coronary Syndrome; Adenosine; Adenosine Monophosphate; Humans; Lactones; Naphthalenes; Piperazines; Platelet Aggregation Inhibitors; Prasugrel Hydrochloride; Prodrugs; Propionates; Pyridines; Thiophenes; Ticagrelor