FDA notified healthcare professionals that the makers of Plavix have agreed to work with FDA to conduct studies to obtain additional information that will allow a better understanding and characterization of the effects of genetic factors and other drugs (especially the proton pump inhibitors (PPIs)) on the effectiveness of clopidogrel. FDA is aware of published reports that clopidogrel (marketed as Plavix) is less effective in some patients than it is in others.
