Antiplatelets represent a diverse group of agents that share the ability to reduce platelet activity through a variety of mechanisms.
Antithrombotic agents are effective in the
secondary prevention of
ischemic strokes. Most
strokes are caused by a sudden blockage of an artery in the brain (called an
ischaemic stroke) that is usually due to a
blood clot. Immediate treatment with
antiplatelet drugs such as
aspirin may prevent new clots from forming and hence improve recovery after
stroke. Several studies have evaluated the role of one
antiplatelet agent,
aspirin, in reducing
stroke severity. The International
Stroke Trial (IST) of 20,000 patients with
acute stroke from other countries. In this study there was a significant 14% proportional reduction in mortality during the scheduled treatment period (343 [3.3%] deaths among
aspirin-allocated patients vs 398 [3.9%] deaths among placebo-allocated patients; 2p = 0.04). There were significantly fewer recurrent
ischaemic strokes in the
aspirin-allocated than in the placebo-allocated group (167 [1.6%]
vs 215 [2.1%]; 2p = 0.01) but slightly more haemorrhagic
strokes (115 [1.1%] vs 93 [0.9%]. Few studies examined the role of ticlopidin in
acute stroke setting the results showed treatment with
ticlopidine improved the neurologic outcome. In the Examining the Safety of Loading of
Aspirin and
Clopidogrel in
Acute Ischemic Stroke and TIA (LOAD) study, 40 consecutive
ischemic stroke patients were treated with 325 mg of
aspirin and 375 mg of
clopidogrel within 36 hours of symptom onset. Overall, 37.5% (n = 15) of the patients had an improvement of 2 or more points on the NIHSS 24 hours after antiplatelet administration. The antiplatelet efficacy of
aspirin in preventing secondary
stroke was established by three studies conducted in the late 1980s and early 1990s: the Swedish
Aspirin Low-dose Trial (
SALT) trials have demonstrated that
aspirin-even in doses as low as 30 mg/day-reduces secondary
stroke, MI, or vascular death in patients with.
Clopidogrel and
aspirin have been used in combination in patients with diverse arterial
vascular diseases However, combinations of
antithrombotic agents do not necessarily improve clinical efficacy and are typically associated with increased toxicity.