The author responds The points raised by Juurlink 1 in response to our article 2 are worthy of consideration. The release kinetics of the drugs as given in the COGENT trial may have attenuated the potential for a drug-drug interaction. However, in the absence of any further randomized clinical trial of concomitant omeprazole and clopidogrel, extrapolation from the COGENT dataset may be the best evaluation we have of whether there is a real interaction. The observational data are mixed and cannot provide the same level of evidence as a randomized trial. The pharmacokinetic and pharmacodynamic data are fairly consistent, though the relationship with clinical outcomes is uncertain and controversial. Nevertheless, if all proton pump inhibitor options are easily available and similarly priced, to initiate therapy with a proton pump inhibitor that does not have this potential interaction seems prudent.