Paclitaxel is a chemotherapeutic agent marketed under the brand name Taxol among others. Used as a treatment for various cancers, paclitaxel is a mitotic inhibitor that was first isolated in 1971 from the bark of the Pacific yew tree which contains endophytic fungi that synthesize paclitaxel. It is available as an intravenous solution for injection and the newer formulation contains albumin-bound paclitaxel marketed under the brand name Abraxane.

uses

It is recommended in National Institute for Health and Care Excellence (NICE) guidance of June 2001 that it should be used for non-small-cell lung cancer in patients unsuitable for curative treatment, and in first-line and second-line treatment of ovarian cancer. In September 2001, NICE recommended paclitaxel should be available for the treatment of advanced breast cancer after the failure of anthracyclic chemotherapy, but that its first-line use should be limited to clinical trials. In September 2006, NICE recommended paclitaxel should not be used in the adjuvant treatment of early node-positive breast cancer. In 2018, it is approved in the United States for the treatment of breast, pancreatic, ovarian, Kaposi's sarcoma and non-small-cell lung cancers.

Pharmacologic action

Paclitaxel is one of several cytoskeletal drugs that target tubulin. Paclitaxel-treated cells have defects in mitotic spindle assembly, chromosome segregation, and cell division. Unlike other tubulin-targeting drugs, such as colchicine, that inhibit microtubule assembly, paclitaxel stabilizes the microtubule polymer and protects it from disassembly. Chromosomes are thus unable to achieve a metaphase spindle configuration. This blocks the progression of mitosis and prolonged activation of the mitotic checkpoint triggers apoptosis or reversion to the G0-phase of the cell cycle without cell division.

side effects

Common side effects include hair loss, bone marrow suppression, numbness, allergic reactions, muscle pains, and diarrhea. Other serious side effects include heart problems, increased risk of infection, and lung inflammation.There are concerns that use during pregnancy may cause birth defects.Paclitaxel is in the taxane family of medications. It works by interference with the normal function of microtubules during cell division.