5-fluorouracil

Definition

5-fluorouracil (5-FU) is a chemotherapy medication used primarily to treat various types of cancer, particularly colorectal, breast, and stomach cancers. It works by inhibiting DNA synthesis in cancer cells, thereby preventing their growth and division. This drug is often used in combination with other therapies to enhance its effectiveness and is a key component in the management of solid tumors.

5 Must Know Facts For Your Next Test

1. 5-fluorouracil is often administered intravenously or as a topical cream for certain skin cancers.
2. The drug acts primarily by mimicking uracil, leading to the disruption of RNA and DNA synthesis in cancer cells.
3. Patients may experience side effects such as nausea, vomiting, diarrhea, and myelosuppression due to its impact on healthy rapidly dividing cells.
4. 5-FU can be combined with leucovorin to enhance its effectiveness, particularly in treating colorectal cancer.
5. Monitoring patients for potential toxicity is crucial, especially in those with reduced DPD enzyme activity, which can lead to severe side effects.

Review Questions

• How does 5-fluorouracil function at the cellular level to combat cancer, and what implications does this have for normal cells?
  • 5-fluorouracil functions by mimicking uracil, which disrupts RNA and DNA synthesis in cancer cells. This inhibition leads to cell cycle arrest and ultimately cell death. However, because normal cells that rapidly divide, such as those in the gastrointestinal tract and bone marrow, are also affected by 5-FU, patients may experience significant side effects like nausea and myelosuppression. Understanding this mechanism helps clinicians balance efficacy against potential toxicity.
• Discuss the importance of combining 5-fluorouracil with other treatments in oncology practice.
  • Combining 5-fluorouracil with other treatments is vital because it can enhance therapeutic effectiveness while potentially reducing resistance. For instance, pairing it with leucovorin can improve response rates in colorectal cancer by stabilizing the binding of 5-FU to its target enzymes. This synergy allows for more aggressive treatment regimens that can lead to better patient outcomes, particularly in advanced-stage cancers where monotherapy may be less effective.
• Evaluate the impact of genetic factors, such as DPD enzyme activity, on patient response to 5-fluorouracil therapy.
  • Genetic factors significantly influence how patients respond to 5-fluorouracil therapy, particularly variations in dihydropyrimidine dehydrogenase (DPD) activity. Patients with reduced DPD activity can experience heightened toxicity from standard doses of 5-FU due to impaired drug metabolism. Evaluating a patient's genetic makeup can guide personalized treatment plans, allowing for dosage adjustments that optimize efficacy while minimizing adverse effects. This approach not only improves patient safety but also enhances the overall effectiveness of cancer treatment.

Related terms

Antimetabolite: A class of drugs that interfere with the metabolic processes of cells, particularly in rapidly dividing cells, such as cancer cells.

Chemotherapy: A type of cancer treatment that uses drugs to kill or slow the growth of cancer cells.

Dihydropyrimidine dehydrogenase (DPD): An enzyme responsible for the metabolism of 5-fluorouracil; variations in DPD activity can affect the drug's efficacy and toxicity.