Oral Bladder cancer, Breast cancer, Carcinoma of gallbladder, Colorectal cancer, Gastric cancer, Liver cancer, Lung cancer, Pancreatic carcinoma, Prostate cancer, Squamous cell carcinoma of the head and neck
Adult: Available preparation:
Tegafur 100 mg and uracil 224 mg
3-6 cap daily in 2-3 divided doses for 28 consecutive days, followed by a 7-day interval. If toxicity occurs, dose may be modified or withheld.
Oral Cervical cancer
Adult: Available preparation:
Tegafur 100 mg and uracil 224 mg
6 cap daily in 2-3 divided doses for 28 consecutive days, followed by a 7-day interval. If toxicity occurs, dose may be modified or withheld.
Oral Metastatic colorectal cancer
Adult: Available preparation:
Tegafur 100 mg and uracil 224 mg
In combination with calcium folinate: 300 mg/m2 daily in 3 divided doses for 28 consecutive days, followed by a 7-day interval. If toxicity occurs, dose may be modified or withheld.
Administration
Should be taken on an empty stomach. Take at least 1 hr before or 1 hr after meals.
Contraindications
Pregnancy and lactation. Concomitant use with sorivudine.
Special Precautions
Patient with bone marrow suppression, gastrointestinal ulcer, haemorrhage or obstruction; infections, cardiac impairment, DPD deficiency. Hepatic and renal impairment.
Adverse Reactions
Significant: Diarrhoea, dehydration, gastrointestinal ulcer or haemorrhage. Rarely, leukoencephalopathy, angina, interstitial pneumonia, anosmia. Endocrine disorders: Rarely, pancreatitis. Gastrointestinal disorders: Nausea, vomiting, constipation, stomatitis, abdominal pain. General disorders and administration site conditions: Fatigue, asthenia. Hepatobiliary disorders: Jaundice. Investigations: Increased ALT/AST, bilirubin, alkaline phosphatase, BUN, and creatinine; rarely, abnormal ECG. Metabolism and nutrition disorders: Anorexia. Renal and urinary disorders: Rarely, haematuria, proteinuria. Skin and subcutaneous tissue disorders: Alopecia, pigmentation, dermatitis, nail abnormality. Rarely, photosensitivity. Potentially Fatal: Haemorrhagic, ischemic or necrotic enteritis. Rarely, bone marrow suppression (e.g. anaemia, leucopenia, thrombocytopenia, pancytopenia, agranulocytosis), fulminant hepatitis, hepatic cirrhosis.
Monitoring Parameters
Monitor CBC, LFT and kidney function.
Overdosage
Symptoms: Bone marrow suppression, nausea, vomiting, diarrhoea, gastrointestinal ulcer and haemorrhage. Management: Supportive and symptomatic treatment.
Drug Interactions
Increased adverse reactions with other chemo- or radio-therapy (e.g. tegafur, gimeracil and oteracil combination therapy). Increased adverse reactions of phenytoin, warfarin. Potentially Fatal: Increased risk of severe blood dyscrasia with sorivudine.
Food Interaction
Decreased absorption with food.
Action
Description: Mechanism of Action: Tegafur is a prodrug of 5-fluorouracil (5-FU) which is further metabolised into its active metabolite, 5-fluoro-deoxyuridine-monophosphate (FdUMP). FdUMP inhibits thymidylate synthase and DNA synthesis.
Uracil inhibits dihydropyrimidine dehydrogenase (DPD), the main enzyme metabolising 5-FU, thereby increasing 5-FU exposure and antineoplastic activity. Pharmacokinetics: Absorption: Tegafur: Rapidly absorbed from the gastrointestinal tract. Decreased absorption with food (5-FU). Time to peak plasma concentration: 1-2 hours; 30-60 minutes (5-FU).
Uracil: Rapidly absorbed from the gastrointestinal tract. Decreased absorption with food. Time to peak plasma concentration: Approx 30 minutes. Distribution: Tegafur: Crosses the blood-brain barrier. Plasma protein binding: 52%. Metabolism: Tegafur: Slowly metabolised in the liver via oxidation by CYP2A6 and via hydrolysis into 5-FU. Excretion: Tegafur: Via urine (<20% as unchanged drug). Terminal elimination half-life: 11 hours.
Uracil: Terminal elimination half-life: 20-40 minutes.
Chemical Structure
Tegafur Source: National Center for Biotechnology Information. PubChem Database. Tegafur, CID=5386, https://pubchem.ncbi.nlm.nih.gov/compound/Tegafur (accessed on Jan. 23, 2020)
Uracil Source: National Center for Biotechnology Information. PubChem Database. Uracil, CID=1174, https://pubchem.ncbi.nlm.nih.gov/compound/Uracil (accessed on Jan. 23, 2020)
Storage
Store below 25°C.
This is a cytotoxic drug. Follow applicable procedures for receiving, handling, administration, and disposal.