Quick Facts About: Fluorouracil

5-FU, 5-fluorouracil, Adrucil

Yes, in 2000.

Colorectal cancer (systemic treatment). Fluorouracil can be administered at different stages of colorectal cancer as part of a chemotherapeutic regimen.

Fluorouracil is administered intravenously.

Dosage is dependent on drug combination in the treatment regimen and is based on the patient’s body surface area (milligram per square meter, mg/m²).

Fluorouracil can be administered in combination with other chemotherapeutic agents:

• Fluorouracil + leucovorin
• Fluorouracil + oxaliplatin OR irinotecan
• Fluorouracil + mitomycin

The dosage administered ranges from 200-600 mg/m², depending on whether it is done through a bolus injection or an infusion.

The following contraindications apply and fluorouracil should be avoided:

• Near-complete or total absence of dihydropyrimidine dehydrogenase (DPD) activity
• Bone marrow depression
• Serious infections such as chickenpox or herpes zoster
• Seriously debilitation
• Concomitant use with antiviral nucleoside drugs and live vaccines
• Pregnancy and lactation

Special precautions are required for the following patient groups:

• Those with history of heart disease
• Partial DPD deficiency
• Renal and hepatic impairment

Fluorouracil can lead to a decrease in red blood cell, white blood cell and platelet count. Lower red blood cell levels may result in fatigue, while a lowered white blood cell count can increase the risk of infections. Platelet decrease may lead to excessive bleeding.

Other common side effects include

• Diarrhea
• Stomach pain
• Nausea
• Vomiting
• Mouth ulcers
• “Hand and foot syndrome” — numbness and pain in palms and soles
• Fatigue
• Hair loss

In severe cases, fluorouracil may also have potentially fatal side effects, including bone marrow suppression, gastrointestinal toxicity and cardiotoxicity.

Seek immediate medical attention for severe side effects, and avoid sun exposure due to increased skin sensitivity.

Fluorouracil is a type of chemotherapy.

Fluorouracil is an antimetabolite. Antimetabolites bear resemblance to normal body molecules but have slightly different structures that prevent cancer cells from working properly. In the case of fluorouracil, it is an analog of the pyrimidine nucleic acid Thymine (T), and can be misincorporated into DNA and RNA in place of uracil (U) and thymine.

Fluorouracil exerts its anticancer effect by interfering with the normal processes of DNA and RNA synthesis. It is a prodrug that undergoes enzymatic conversion to its active form, 5-fluoro-2'-deoxyuridine monophosphate (FdUMP). FdUMP is an analog of thymidine monophosphate, which is a building block of DNA. FdUMP binds to and inhibits the activity of thymidylate synthase (TS), which is an enzyme required for the production of thymidine. Thymidine is essential for DNA synthesis, and the inhibition of TS enzyme by FdUMP leads to a deficiency of thymidine in the cancer cells, thereby preventing DNA synthesis and cell division.

In addition to inhibiting DNA synthesis, fluorouracil also interferes with RNA synthesis by inhibiting the activity of RNA polymerase. RNA polymerase is an enzyme required for the production of RNA, which is essential for protein synthesis. The inhibition of RNA polymerase by fluorouracil leads to a decrease in the production of RNA and, consequently, a decrease in protein synthesis, which is required for the growth and division of cancer cells.