BioInteractor utilizes data on drug-target, -enzyme and -transporter associations to provide insight on drug-drug interactions. It allows you to identify, for instance, which drugs act similarly on the same target. Such drugs may have additive pharmacodynamic effects if given concomitantly. Conversely, two drugs may antagonize the beneficial effects of each other by having opposite actions on a specific drug target. BioInteractor uses ranked drug-enzyme association information to predict enzyme-mediated drug interactions that may be clinically relevant.