Brands, Medical Use, Clinical Data
- Antineoplastic Agents, Phytogenic
- Radiation-Sensitizing Agents
- Solution: single-dose vials containing 20 mg (0.5 mL) or 80 mg (2 mL) docetaxel (anhydrous).
Brands / Synonyms
Docetaxel anhydrous; Docetaxel, Trihydrate; Taxotere; Taxotere
For the treatment of patients with locally advanced or metastatic breast cancer after failure of prior chemotherapy. Also used as a single agent in the treatment of patients with locally advanced or metastatic non-small cell lung cancer after failure of prior platinum-based chemotherapy. Lastly, for use, in combination with prednisone, in the treatment of patients with androgen independent (hormone refractory) metastatic prostate cancer.
Docetaxel is a taxoid antineoplastic agent. It promotes the assembly of microtubules from tubulin dimers and stabilizes microtubules by preventing depolymerization. This stability results in the inhibition of the normal dynamic reorganization of the microtubule network that is essential for vital interphase and mitotic cellular functions. In addition, docetaxel induces abnormal arrays or "bundles" of microtubules throughout the cell cycle and multiple asters of microtubules during mitosis.
Mechanism of Action
Docetaxel interferes with the normal function of microtubule growth. Whereas drugs like colchicine cause the depolymerization of microtubules in vivo, docetaxel arrests their function by having the opposite effect; it hyper-stabilizes their structure. This destroys the cell's ability to use its cytoskeleton in a flexible manner. Specifically, docetaxel binds to the β-subunit of tubulin. Tubulin is the "building block" of mictotubules, and the binding of docetaxel locks these building blocks in place. The resulting microtubule/docetaxel complex does not have the ability to disassemble. This adversely affects cell function because the shortening and lengthening of microtubules (termed dynamic instability) is necessary for their function as a transportation highway for the cell. Chromosomes, for example, rely upon this property of microtubules during mitosis. Further research has indicated that docetaxel induces programmed cell death (apoptosis) in cancer cells by binding to an apoptosis stopping protein called Bcl-2 (B-cell leukemia 2) and thus arresting its function.
Oral LD50 in rat is >2000 mg/kg. Anticipated complications of overdosage include: bone marrow suppression, peripheral neurotoxicity, and mucositis. In two reports of overdose, one patient received 150 mg/m2 and the other received 200 mg/m2 as 1-hour infusions. Both patients experienced severe neutropenia, mild asthenia, cutaneous reactions, and mild paresthesia, and recovered without incident.
Biotrnasformation / Drug Metabolism
Hepatic. In vitro drug interaction studies revealed that docetaxel is metabolized by the CYP3A4 isoenzyme (1 major, 3 minor metabolites).
TAXOTERE is contraindicated in patients who have a history of severe hypersensitivity reactions to docetaxel or to
other drugs formulated with polysorbate 80.
TAXOTERE should not be used in patients with neutrophil counts of <1500 cells/mm3.
There have been no formal clinical studies to evaluate the drug interactions of TAXOTERE with other medications.
In vitro studies have shown that the metabolism of docetaxel may be modified by the concomitant administration
of compounds that induce, inhibit, or are metabolized by cytochrome P450 3A4, such as cyclosporine, terfenadine,
ketoconazole, erythromycin, and troleandomycin. Caution should be exercised with these drugs when treating patients
receiving TAXOTERE as there is a potential for a significant interaction.