What is Paclitaxel used for?

Introduction

Paclitaxel is a widely used drug developed since the mid-1980s, with significant antitumor activity against ovarian, head and neck, bladder, breast and lung cancers. Paclitaxel promotes microtubule assembly and stabilizes microtubule dynamics, inhibiting cell proliferation and induction of apoptosis. Paclitaxel is a water-insoluble drug. Currently, it is formulated in a mixture of Cremophor EL (polyoxyethylated castor oil) and ethanol (1:1, w/w) (C/E formulation). Intravenous administration of this formulation resulted in peak paclitaxel concentration in plasma at the first sampling time, followed by biphasic declines over time. Paclitaxel disposition is nonlinear, in part due to the presence of Cremophor. Hepatic metabolism and biliary excretion are the main elimination pathways for the C/E formulation. The dose-limiting toxicity of paclitaxel is neutropenia, which is related to the time that plasma paclitaxel concentrations are at or above a threshold value. The use of Cremophor is also associated with hypersensitivity reactions. Many approaches have been focused on developing safer formulations.

Paclitaxel belongs to the group of medicines called antineoplastics. It interferes with the growth of cancer cells, which are eventually destroyed. Since the growth of normal body cells may also be affected, other unwanted effects will also occur. Some of these may be serious and must be reported to your doctor. Other effects may not be serious but may cause concern. Some effects may not occur until months or years after the medicine is used.

Indications

Paclitaxel is approved to be used alone or with other drugs to treat:

AIDS-related Kaposi sarcoma. It is used as second-line therapy.

Breast cancer. It is used:

In patients with node-positive cancer. It is given as adjuvant therapy with doxorubicin hydrochloride-containing combination chemotherapy.

In patients with metastatic cancer that did not respond to combination chemotherapy.

Non-small cell lung cancer. It is used with cisplatin as first-line therapy in patients whose cancer cannot be treated with surgery or radiation therapy.

Ovarian cancer is advanced. It is used with cisplatin as first-line therapy or alone in patients who have already received other treatments.

Paclitaxel is also being studied in the treatment of other types of cancer.

Paclitaxel is also available in a different form called paclitaxel albumin-stabilized nanoparticle formulation.

References

[1] Paclitaxel (Intravenous Route) Description and Brand Names - Mayo Clinic https://www.mayoclinic.org/drugs-supplements/paclitaxel-intravenous-route/description/drg-20065247

[2] Paclitaxel - NCI (cancer.gov) https://www.cancer.gov/about-cancer/treatment/drugs/paclitaxel