Irinotecan

Definition

Irinotecan is a chemotherapy drug used primarily in the treatment of metastatic colorectal cancer. It works by inhibiting the enzyme topoisomerase I, which is essential for DNA replication, thereby preventing cancer cells from dividing and growing.

5 Must Know Facts For Your Next Test

1. Irinotecan is often used in combination with other drugs, such as fluorouracil and leucovorin, to enhance its effectiveness against colorectal cancer.
2. The drug can cause significant side effects, including diarrhea and myelosuppression, which is a decrease in bone marrow activity leading to reduced blood cell production.
3. Dosing of irinotecan can vary based on the patient's genetic makeup, particularly variations in the UGT1A1 gene, which affects drug metabolism.
4. Irinotecan is administered intravenously, typically in cycles, allowing time for recovery between treatments.
5. Research is ongoing to evaluate irinotecan's effectiveness in treating other types of cancer beyond colorectal cancer, such as pancreatic and lung cancers.

Review Questions

• How does irinotecan function at a molecular level to inhibit cancer cell growth?
  • Irinotecan functions by targeting the enzyme topoisomerase I, which is crucial for DNA replication. By inhibiting this enzyme, irinotecan prevents the unwinding of DNA strands necessary for replication, ultimately leading to cell death. This action specifically affects rapidly dividing cancer cells, making it an effective treatment for conditions like metastatic colorectal cancer.
• Discuss the importance of genetic factors in determining irinotecan dosing and potential side effects.
  • Genetic factors play a significant role in how patients metabolize irinotecan. Variations in the UGT1A1 gene can lead to differences in drug clearance rates, impacting both efficacy and toxicity. Patients with certain genotypes may experience more severe side effects such as diarrhea and myelosuppression. Therefore, understanding a patient's genetic profile can help healthcare providers personalize dosing regimens and mitigate risks associated with irinotecan treatment.
• Evaluate the potential implications of combining irinotecan with other chemotherapy agents in treating advanced cancers.
  • Combining irinotecan with other chemotherapy agents, such as fluorouracil and leucovorin, has shown promise in enhancing treatment efficacy for advanced cancers like metastatic colorectal cancer. This combination approach leverages different mechanisms of action to target cancer cells more effectively. However, it also raises concerns regarding cumulative side effects and the need for careful patient monitoring. Evaluating these combinations through clinical trials is crucial for optimizing treatment protocols while managing patient safety.

Related terms

Topoisomerase: An enzyme that alters the supercoiled form of a DNA molecule, playing a critical role in DNA replication and transcription.

Chemotherapy: A type of cancer treatment that uses drugs to kill or slow the growth of cancer cells, often affecting rapidly dividing cells throughout the body.

Metastatic Cancer: Cancer that has spread from its original site to other parts of the body, making it more challenging to treat.