Safety and tolerability of 600 mg Clopidogrel bolus in patients with acute ischemic stroke: Preliminary experience

Background: There is a high risk of recurrence within the first 72 hours of ischemic stroke. Without bolus, the peak effect of clopidogrel may be delayed for 72 hours. A bolus may shorten this time but its safety in acute ischemic stroke is unknown. Material/Methods: All patients with acute ischemic stroke or transient ischemic attack within a 10 month period were administered 600 mg clopidogrel bolus if they were already taking aspirin regularly, or had aspirin allergy or intolerance. Demographic data, duration to initiation of therapy, National Institute of Health Stroke Scale score (NIHSSS) at baseline and at 24 hours were collected. Brain imaging studies were reviewed for hemorrhagic transformation. Wilcoxin rank sum test was used for comparison of NIHSSS over time. Results: A total of 20 patients (mean age 66±14, men n=8) were loaded with clopidogrel because of aspirin failure (n=16), aspirin allergy (n=1), aspirin intolerance secondary to gastritis (n=2) or stent placement in the setting of acute stroke (n=1). Median time interval between clopidogrel bolus and symptom onset was 25 hours. The median NIHSSS at 24 hours (1, range 0-15) was significantly (p<0.01) lower than the NIHSSS at baseline (3, range 0-24). Neurological deterioration (NIHSSS increase ≥4 points) or hemorrhagic transformation was not seen in any patient. Conclusions: A 600 mg clopidogrel bolus prior to initiating regular dose clopidogrel in the setting of acute ischemic stroke was safe. The potential for risk reduction in early recurrent stroke needs to be studied in future studies.