Generic Name: Paclitaxel Brand Name(s): Taxol®, Abraxane®, Onxol® IUPAC: 5 beta,20-Epoxy-1,2a,4,7 beta,10 beta,13 alpha-hexahydroxytax-11-en-9-one 4,10-diacetate 2-benzoate 13-ester with (2 R,3S)-N-benzoyl-3-phenylisoserine FDA Approval: yes Manufacturer Link
Usage: In December of 1992, the FDA approved paclitaxel for the treatment of ovarian cancer. Today the drug is used for a several types of cancer, including ovarian, breast, small cell and large cell lung cancers, and Kaposi's sarcoma. (1) Paclitaxel is administered as a series of intravenous injections.
Abraxane is a form of paclitaxel in which the drug is coupled to albumin, a human protein. This form of the drug can be administered more quickly and does not induce hypersensitivity (allergic) reactions.
Paclitaxel can be used in combination with other chemotherapy drugs. In combination with cisplatin, paclitaxel is used for the first line treatment of non-small cell lung cancers. Paclitaxel and carboplatin can be used to treat cancer of the lungs and the ovaries.
Mechanism: Paclitaxel (Taxol®) binds to microtubules and prevents their breakdown. The movement of the replicated chromosomes during mitosis requires both polymerization of tubulin to form microtubules as well as the breakdown of those microtubules. In the presence of paclitaxel, chromosomes are unable to move to opposite sides of the dividing cell because microtubules are not broken down. Cell division is halted, and cell death is induced. This mechanism can be contrasted with the Vinca alkaloid chemotherapy drugs (i.e. vinblastine) which work by preventing tubulin polymers from forming.
Dr. Monroe E. Wall and Dr. Mansukh C. Wani discovered paclitaxel (Taxol®) at the Research Triangle Institute in 1967. They isolated the compound from the Pacific Yew tree (Taxus brevifolia) and tested it as an anti-tumor drug in rodents. The mechanism of action for paclitaxel was reported by scientists at the Albert Einstein Medical College in 1980.
Side Effects: Common side effects include reduction in bone marrow function which may result in anemia, blood in stools or black stools, fast or irregular heartbeat, fever, chills, lower back pain, numbness or tingling of the hands or feet, mouth sores, painful, bloody, or difficult urination, swelling of the face, lips, or throat, nausea, vomiting, or diarrhea, unusual bleeding or bruising, wheezing or trouble breathing, hair loss.(3)(3)
Contraindications: The drug may cause birth defects. Patients should not take this drug if they are pregnant or plan to become pregnant. Breast feeding should also be avoided by patients taking paclitaxel. Immunosuppression may lead to increased risk of infection. Patients should tell their clinician if they are currently taking any other medications.