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A3. The Toxicity and Side Effects of Taxol

Although taxol shows activity against a range of tumours it's use is associated with a number of toxic side effects.

Taxol is only sparingly soluble in water and so intravenous administration depends on the use of Cremophor EL (polyethoxylated castor oil) to obtain a sufficiently concentrated solution.  Unfortunately, use of Cremophor increases patient toxicity and can lead to hypersensitivity reactions in certain individuals.  In order to overcome these problems doctors have attempted to prolong the infusion schedules, and so lessen the shock to the patients system, or use corticosteroids and antihistamines as part of the premedication given29.  A better alternative would be the development of an analogue of taxol that is more soluble in water and so remove the necessity to use Cremophor solutions.

Hypersensitivity symptoms

Adverse effects include peripheral neuropathy, mucositis, alopecia, neutropenia, cardiotoxicity, diarrhea, and hypotension32.

Common Side Effects

Taxol is generally tolerated by patients much better than other anti cancer drugs on the market.  It lacks the very severe side effects of chemotherapy treatment and is less harmful to normal healthy cells29.   However, the mechanism by which taxol works means that some side effects are inevitable.  Currently, documented side effects include:

  1. Nausea (severe in some cases)
  2. Tingling in fingers and toes
  3. Numbness
  4. Reduction in white blood cell count
  5. Poor blood circulation
  6. Fluid retention

There are various methods used to try to reduce the severity of some of these side effects.  A growth factor, a protein called granulocyte colony stimulating factor, can be administered to protect bone marrow from attack thereby reducing the loss of white blood cells.  Blood thinning agents can be administered to improve blood circulation but their associated side effects can tend to make matters worse.  Fluid retention is reduced by giving oral corticosteroids, such as dexamethasone, prior to treatment.