Gemcitabine hydrochloride is a medication used in the treatment of various types of cancer, including pancreatic cancer, lung cancer, breast cancer, and bladder cancer. It belongs to a class of drugs called antimetabolites.

Gemcitabine hydrochloride works by interfering with the DNA synthesis and function in cancer cells, ultimately leading to their destruction. Specifically, it inhibits the replication of DNA and RNA, which are essential for cancer cell growth and proliferation.