Comparison of critical drug-drug interaction listings: the Department of Veterans Affairs medical system and standard reference compendia.

The objective of this study was to evaluate the agreement among the US Department of Veterans Affairs (VA) listing of "critical" drug-drug interactions (DDIs) and two standard drug-interaction compendia. A list of critical DDIs, as defined by the VA, was compared with two standard commercially available compendia (Micromedex DRUG-REAX and Drug Interactions: Analysis and Management (DIAM)) in order to determine the level of agreement among the systems. Of 982 DDIs classified as critical by the VA, only 136 DDIs (13.7%) were considered critical in all three systems. Our conclusion was that, overall, there is poor agreement among the compendia and the VA system.