The impact of generic clopidogrel bisulfate on platelet inhibition in patients with coronary artery stents: results of the ACCEL-GENERIC study.
OBJECTIVE
In patients with coronary artery stents, the cost of clopidogrel has been cited as a factor in the premature discontinuation of therapy. Thus, the introduction of lower-cost generic clopidogrel may increase patient compliance. However, platelet inhibition by generic clopidogrel has not been compared to the original clopidogrel formulation in patients with coronary artery stents.


METHODS
We prospectively enrolled 20 patients receiving chronic therapy with the original clopidogrel bisulfate (Plavix). After assessing patient compliance with Plavix, maintenance therapy was switched to generic clopidogrel bisulfate (Plavitor). Platelet reactivity was assessed at baseline and 30-day after the switch using conventional aggregometry and the VerifyNow P2Y12 assay.


RESULTS
All patients completed maintenance therapy with Plavitor. Before and after switching therapy maximal (36.5 +/- 7.9% vs. 39.8 +/- 16.2%, p = 0.280) and late platelet aggregation (23.5 +/- 10.9% vs. 29.1 +/- 18.3%, p = 0.156) with 5 micromol/L adenosine diphosphate (ADP) stimulus did not differ. Likewise, 20 micromol/L ADP-induced platelet aggregation and P2Y12 reaction unit in patients on Plavitor therapy was comparable to that in patients on Plavix therapy. However, Bland-Altman analysis showed wide limits of agreement between measured platelet reactivity on Plavix vs. Plavitor therapies.


CONCLUSIONS
Among patients on Plavix maintenance therapy with coronary stents, replacement with Plavitor shows a comparable inhibition of ADP-induced platelet aggregation. However, due to poor inter-therapy agreement, between two regimens, physicians may be cautious when introducing generic clopidogrel bisulfate.
Department of Internal Medicine, Gyeongsang National University Hospital, Jinju, Korea. goodoctor@naver.com
Young-Hoon
YH
Jeong
Jin-Sin
JS
Koh
Min-Kyung
MK
Kang
Yeon-Jeong
YJ
Ahn
In-Suk
IS
Kim
Yongwhi
Y
Park
Seok-Jae
SJ
Hwang
Choong Hwan
CH
Kwak
Jin-Yong
JY
Hwang
D000368:Aged; D015906:Angioplasty, Balloon, Coronary; D000077144:Clopidogrel; D003131:Combined Modality Therapy; D003324:Coronary Artery Disease / Q000188:drug therapy* / Q000628:therapy; D054855:Drug-Eluting Stents; D016568:Drugs, Generic / Q000008:administration & dosage* / Q000009:adverse effects; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010349:Patient Compliance; D010974:Platelet Aggregation / Q000187:drug effects; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage* / Q000009:adverse effects; D011446:Prospective Studies; D018048:Receptors, Purinergic P2 / Q000378:metabolism; D058925:Receptors, Purinergic P2Y12; D013988:Ticlopidine / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives*
D016568:Drugs, Generic; C548576:P2RY12 protein, human; D010975:Platelet Aggregation Inhibitors; D018048:Receptors, Purinergic P2; D058925:Receptors, Purinergic P2Y12; D000077144:Clopidogrel; D013988:Ticlopidine