Abstract TP413: Monitoring Of Clopidogrel-related Inhibition In Patients Presenting With Acute Cerebral Ischemia Following Generic Substitution Of Clopidogrel For Cardiovascular Prevention.
Background&Purpose: The European Medicines Agency has recently approved numerous generic versions of clopidogrel for the prevention of cardiovascular diseases. We previously observed a trend in our population based study that patients who switched to generic clopidogrel experienced strokes soon after substitution. We aimed to evaluate platelet function in patients experiencing acute cerebral ischemia (ACI) after generic substitution of clopidogrel (GSOC).
Subjects&Methods: We prospectively evaluated consecutive patients who presented with symptoms of ACI and were previously treated with brand or generic clopidogrel for cardiovascular protection. Baseline characteristics, vascular risk factors, use of proton-pump inhibitors (PPI) and secondary prevention therapies were documented in all cases. Responsiveness to clopidogrel was assessed within 24 hours from symptom onset using multiple electrode impedance aggregometry (Multiplate analyzer). The validated cut-off of 52U was used to identify clopidogrel non-responders (≥53 U).
Results: During the first 18-month period we documented 47 patients (mean age 70±10 years; 60%men) presenting with symptoms of ACI (57% acute ischemic stroke, 43% Transient Ischemic Attack). GSOC had occurred within a median of 6 months (range 1-11 months) in 25 cases (53%), while the remaining 22 patients (47%) have been treated only with brand clopidogrel. The clopidogrel groups did not differ (p>0.2) in terms of demographics, vascular risk factors, use of PPIs and secondary prevention therapies. The rate of clopidogrel non-responders tended to be higher in the generic group (44% vs. 23%; p=0.125). After adjusting for demographic characteristics, stroke risk factors, concomitant aspirin or PPI use and secondary prevention therapies, the generic compound tended to be associated with a higher likelihood of clopidogrel non-responsiveness (OR: 6.56; 95%CI: 0.95-45.54; p=0.057)
Conclusions: Our findings indicate that rate of clopidogrel non-responsiveness tends to be higher in patients presenting with symptoms of ACI following its generic substitution. The observed trend poses a question if clopidogrel generics have the same active ingredient and the same labeled strength as the reference product.
- © 2012 by American Heart Association, Inc.