SAFETY antiplatelet drugs

SUMMARY
• Antiplatelet drugs (aspirin, dipyridamole,
clopidogrel), given in single- or dualagent
regimens, are the treatment of
choice for secondary prevention in
ischemic NCS
• Choice of single- or dual-agent therapy
depends upon calculation of safety risk
relative to preventive efficacy
• Key safety concerns are hemorrhage
(aspirin + clopidogrel), GI effects (all antiplatelet
agents) and headache (dipyridamole)
• ESPS-2: Dual therapy with aspirin + ER
dipyridamole significantly improved prevention in
patients with a history of TIA or stroke, without
excess risk of bleeding, compared with aspirin
alone
• ESPRIT: In patients with a history of TIA or minor
stroke, aspirin + dipyridamole resulted in fewer
cardio- or cerebrovascular endpoint events,
including first ischemic stroke, compared with
aspirin alone, with fewer major bleeding
complications; dipyridamole-related headache
was a notable cause of study withdrawal
• MATCH: Adding aspirin to clopidogrel did not
significantly reduce risk of major vascular events
(including stroke) in patients with stroke/TIA
history, but did significantly increase risk of lifethreatening,
major, and minor bleeding
• CHARISMA: In a broader patient population than
MATCH (with multiple atherothrombotic risk
factors or symptomatic, documented vascular
disease), vascular events were not significantly
reduced, but moderate bleeding was
significantly increased, with the combination of
aspirin + clopidogrel compared with aspirin
alone
• Based on available evidence, AHA guidelines
advise the practicing physician to prescribe:
• Aspirin
• The combination of aspirin and ER
dipyridamole or clopidogrel monotherapy for
survivors of stroke or TIA
• Aspirin + ER dipyridamole over aspirin alone
to avoid routine use of dual therapy with aspirin
+ clopidogrel because of excess bleeding risk
• The complex histories of many poststroke and
post-TIA patients require an individual approach,
considering the need for anticoagulation, use of
aspirin + clopidogrel post-PCI, bleeding risks,
and the potentials for drug allergy, resistance,
and intolerance