Paclitaxel is a chemotherapeutic drug that belongs to a class of compounds known as taxanes, compounds that can be found in various natural sources. Discovered and isolated from the bark of the Pacific yew tree in 1967, it was then named taxol. The name paclitaxel was given as the generic name by Bristol-Myers Squibb (BMS) when it was developed commercially and the BMS compound sold under the trademark ‘Taxol’. A different formulation of the drug is sold under the trademark ‘Abraxane’ by Abraxis Bioscience. Paclitaxel is a mitotic inhibitor; it promotes the formation of microtubules during cell division by binding to these structures. This prevents the normal progression of cell division making the cells unable to divide into daughter cells. Research results also suggest that paclitaxel induces programmed cell death or apoptosis.
Paclitaxel was approved by the United States Food and Drug Administration in 1992 for use as treatment of breast, ovarian and lung cancer and as second line treatment of Kaposi’s sarcoma, an AIDS related tumor. Paclitaxel is also used to treat head and neck cancer, non-small cell lung cancer, small cell lung cancer, and bladder cancer. It is also under investigation for use in treatment of mesothelioma. Paclitaxel is used alone and in combination with cisplatin, a platinum-containing chemotherapeutic drug. It is currently prescribed wordwide and is administered intravenously once every 2 or 3 weeks. Paclitaxel injection is available in 30 mg (5 ml) and 100 mg (16.7 ml) multidose vials. Side effects include suppression of bone marrow function, nausea and vomiting, hypersensitivity, infection, hair loss and weight loss.