Irinotecan hydrochloride (anhydrous) is a hydrochloride formed by combining irinotecan with one molar equivalent of hydrochloric acid. It is used in its trihydrate form in combination with fluorouracil and leucovorin to treat metastatic pancreatic adenocarcinoma following gemcitabine-based therapy. Upon hydrolysis of the carbamate linkage, it converts to its active metabolite SN-38, which is approximately 1000 times more active. It functions as a DNA topoisomerase inhibitor, antineoplastic agent, apoptosis inducer, and prodrug. It contains irinotecan(1+).