Executive Summary

Although proton pump inhibitors do have a negative influence on the antiplatelet effects of clopidogrel (Bristol-Myers Squibb/Sanofi-Aventis' Plavix) and prasugrel (Lilly/Daiichi Sankyo's Effient), the antacids don't appear to interfere with the clinical outcome for patients, according to an analysis of data from the TIMI-44 and TIMI-38 trials presented Sept. 1 at the European Society of Cardiology congress. The antacids are thought to inhibit the conversion of the thienopyridine class drugs into active form in the body, and the drug-drug interaction has sparked safety warnings from both FDA and EMEA. Professional guidelines, however, still recommend administering PPIs with the antiplatelet drugs to help reduce the risk of gastrointestinal bleeding. AstraZeneca's experimental antiplatelet drug Brilinta (ticagrelor), for which positive Phase III data was presented at ESC, may offer a solution to the interaction dilemma if it is approved as anticipated in 2010. Ticagrelor has a different mechanism of action from clopidogrel or prasugrel; it is an active compound that does not require bioactivation (1"The Pink Sheet," Sept. 7, 2009)