Irinotecan Hydrochloride Trihydrate

Irinotecan hydrochloride trihydrate (CPT 11), a compound within the camptothecin family, is an inhibitor of Topo I (topoisomerase I) involved in cellular DNA replication and transcription. This compound is a prodrug which needs to be transformed by carboxylesterases to its active metabolite SN-38. As a Topo I inhibitor, Irinotecan inhibits the religation step of the enzyme's normal action, inducing single stranded DNA breaks. These single stranded breaks are then converted to double-stranded breaks within the course of DNA replication which is reported to induce apoptosis or repair mechanisms as a result. Irinotecan has a therapeutic effect in malignant brain tumors, with increased efficacy when combined in neural stem cells therapies.