Background: Clopidogrel exists in different salt formulations. All published data that have demonstrated its beneficial effect are based entirely on the hydrogen sulphate salt contained in the branded product Plavix, which had US sales of $6.1 billion in 2010 alone. A number of cheaper generic versions of clopidogrel are increasingly being used in Europe as an alternative to Plavix, mainly for cost reasons. However, there is insufficient evidence to show that their pharmacodynamic effect is equivalent to Plavix.
Methods: This prospective study investigated whether there is any significant difference in the antiplatelet effect of Plavix versus generic clopidogrel hydrochloride in healthy male volunteers. All participants received loading and maintenance doses of both drugs, in a crossover manner, separated by a 2-week washout period. Adenosine diphosphate (ADP)–induced platelet reactivity was measured using short thrombelastography at multiple timepoints.
Results: The results showed interindividual heterogeneity in responses to clopidogrel but no significant difference in ADP-induced platelet reactivity between Plavix versus generic clopidogrel hydrochloride.
Conclusions: Our findings suggest comparable inhibition of ADP-induced platelet reactivity with Plavix and generic clopidogrel hydrochloride. This observation is particularly pertinent at a time when the patent for Plavix is expected to expire in the near future leading to the large-scale switch to cheaper generic preparations.
*Wessex Cardiothoracic Unit, University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom
†University of Southampton Faculty of Medicine, Southampton, United Kingdom.
Reprints: Nalyaka Sambu, MBBCh, MRCP, Wessex Cardiothoracic Unit, University Hospital Southampton NHS Foundation Trust, Tremona Road, Southampton SO16 6YD, United Kingdom (e-mail: firstname.lastname@example.org).
Supported by unrestricted grants from Haemonetics and Medtronic United Kingdom.
The author N. Curzen has received unrestricted research funding from Haemonetics, Medtronic, Boston Scientific, and Pfizer. He has also received speaker and consulting fees from Boston Scientific, Abbott, Medtronic, AstraZeneca, Eli Lilly, and Cordis. The remaining authors have no disclosures.
Received May 20, 2012
Accepted August 14, 2012