When it comes to colon cancer that has metastasized to other areas of the body, cancer specialists often prescribe irinotecan for their patients. Irinotecan is one of the cancer medications known as plant alkaloids, and it comes from the Camtotheca acuminata, a tree known in its native China as the "happy tree." These trees have become endangered in China, possibly from their long use in Chinese herbal medicine, but are now grown as a crop in other countries such as India, Japan, and the United States. Irinotecan attacks cancer cells at the stage of DNA synthesis--the DNA within any cell, including cancer cells, must replicate before that cell can divide and multiply. The medication is also known under the brand name Camptosar.®
Administration and Treatment With Irinotecan
Patients usually receive irinotecan through intravenous infusion. This occurs in the setting of either a cancer or infusion clinic, or a hospital. As with any intravenous chemotherapy, it may be useful to have a central line implanted before beginning treatment with irinotecan in order to minimize the risk of infiltration or extravasation that comes with using smaller, peripheral veins. A central line also prevents needing to cause patients the pain and difficulty of an IV stick for each treatment.
Though irinotecan is most commonly used to treat patients with colon cancer that has metastasized to other organs, the treatment plan can differ. It can be used in the initial round of chemotherapy in combination with other medications for colon cancer discovered after it has already metastasized. Or, doctors can prescribe it alone, after previous treatments with other agents that have not been as effective as desired.
Side Effects of Irinotecan
Irinotecan's most potent and common side effect is diarrhea. It can cause both early diarrhea 24 hours after the initiation of treatment, and later onset diarrhea. Doctors and nurses often administer atropine to help minimize the early onset symptoms. The later onset diarrhea can be severe and long-lasting, placing patients in danger of dehydration. Severe cramping often accompanies the diarrhea. Anti-diarrheal medications such as loperamide should be given as soon as symptoms appear. Irinotecan is perhaps the most likely of all chemotherapy agents to cause diarrhea.
Other side effects of irinotecan include myelosuppression--stifling the bone marrow's ability to produce blood cells. The production of red cells is decreased, leaving the patient anemic. The production of white cells is decreased as well, leaving the patient susceptible to infections that can be deadly. Receiving irinotecan can also cause hair to fall out, but it usually grows back after treatment.
Sources:
- Polovich, Martha, Julie M. Whitford, and MiKaela Olsen, eds. Chemotherapy and Biotherapy Guidelines and Recommendations for Practice. Pittsburgh, PA: Oncology Nursing Society, 2009.
- Wilson, Billie, Margaret T. Shannon, and Kelly M. Shields, Prentice Hall Nurse's Drug Guide 2009, Upper Saddle River, NJ: Prentice Hall, 2008.
Disclaimer: The information contained in this article is for educational purposes only and should not be used for diagnosis or to guide treatment without the opinion of a health professional. Any reader who is concerned about his or her health should contact a doctor for advice.
Elizabeth Thomas - Elizabeth was born and raised in Mt. Clemens, Michigan, though she now lives in a suburb of Austin, Texas. She holds a bachelor's and ...
