A high-content bioorthogonal prodrug with multiple outputs using the "click, cyclize, and release" concept is described. The proof of concept is established by the co-delivery of a gasotransmitter carbon monoxide, an anticancer drug floxuridine, and an in situ generated fluorescent reporter molecule for real-time monitoring of the prodrug activation. Bioorthogonal prodrugs as such are invaluable tools for the co-delivery of other drug payloads for multimodal therapy.