Paclitaxel and docetaxel

Paclitaxel and docetaxel

Antineoplastic drugs are used to treat metastatic ovarian and breast cancer after chemotherapy has failed. They include:

• paclitaxel
• docetaxel.

Pharmacokinetics

After I.V. administration, paclitaxel is highly bound to plasma proteins. Docetaxel is administered I.V. with a rapid onset of action.

Metabolism and excretion

Paclitaxel is metabolized primarily in the liver with a small amount excreted unchanged in urine. Docetaxel is excreted primarily in stool.

Pharmacodynamics

Paclitaxel and docetaxel exert their chemotherapeutic effect by disrupting the microtubule network essential for mitosis and other vital cellular functions.

Pharmacotherapeutics

Paclitaxel is used when first-line or subsequent chemotherapy has failed in treating metastatic ovarian cancer as well as metastatic breast cancer.

Warning!

Adverse reactions to altretamine

More than 10% of patients using altretamine in clinical trials experienced adverse reactions, such as:

• nausea and vomiting
• neurotoxicity
• peripheral neuropathy
• anemia.

Bone marrow suppression is also common.

Head, neck, and below

The taxanes may also be used for treating head and neck cancer, prostate cancer, and non’small-cell lung cancer

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Drug interactions

Taxanes may interact with other drugs.

• Concomitant use of paclitaxel and cisplatin may cause additive myelosuppressive effects.
• Cyclosporine, ketoconazole, erythromycin, and troleandomycin may modify the metabolism of docetaxel.
  
  
• Phenytoin may decrease paclitaxel serum level, leading to a loss of efficacy.
• Quinupristin/dalfopristin may increase paclitaxel serum levels, increasing the risk of toxicity.