Catheter devices having an expandable balloon for delivering a therapeutic agent to a body site. The balloon has one or more folds which serve as a reservoir for containing the therapeutic agent. The fold may have any of various configurations to hold the therapeutic agent. In some cases, the balloon comprises one or more lobes that forms the fold(s). The therapeutic agent may be provided in various ways. For example, the therapeutic agent may be contained in packets that rupture upon expansion of the balloon, or as a plurality of discrete bulk masses, or sealed within compartments.