What is the main action of the drug Irinotecan?

Irinotecan primarily functions as a topoisomerase I inhibitor. This is significant because topoisomerase I plays a crucial role in DNA replication and transcription by relaxing supercoiled DNA, thereby allowing access for the DNA replication machinery. By inhibiting this enzyme, irinotecan interferes with the process of DNA replication and transcription, ultimately leading to apoptosis (programmed cell death) in rapidly dividing cancer cells.

Irinotecan is mainly used in the treatment of colorectal cancer and works effectively because it targets the DNA of tumor cells. Its mechanism of action is particularly important in cancer therapy, as it helps to halt the progression of cancer by undermining the cell's ability to divide and proliferate.

Understanding this key action of irinotecan is vital for healthcare professionals in determining appropriate therapeutic regimens and managing potential side effects linked to its use. The effectiveness of irinotecan is often dependent on the cancer type and the specific molecular characteristics of the tumor, emphasizing the need for tailored treatment approaches.