Fluorafur, 400 mg capsules 100 pcs

Pharmacodynamics

Antitumor drug whose action is due to disruption of DNA and RNA synthesis. Formed as a result of hydrolysis fluorouracil inhibits the enzyme thymidylate synthetase and DNA synthesis, penetrates into the RNA structure instead of uracil making it defective and inhibits cell proliferation.

In tumor cells it is converted to 5-fluoro-deoxyuridine-5-monophosphate, which is then phosphorylated to triphosphate and incorporated into RNA, and floxuridine monophosphate, which inhibits thymidylate synthetase. It is less toxic and better tolerated by patients than 5-fluorouracil.

Pharmacokinetics

Absorption

Ingestion of tegafur is rapidly absorbed from the GI tract and is detectable in the blood for at least 24 hours after a single administration. C_max of tegafur in plasma is reached within 4-6 h after administration. Bioavailability is almost complete.

Distribution

It has high lipophilicity (200 times higher than fluorouracil) while remaining a water-soluble compound. High lipophilicity allows fast passage through biological membranes, distribution in the body and penetration through the BBB.

Metabolism

Metabolized in the liver with the formation of metabolites, among which the pharmacologically active 5-fluorouracil is central. Bioactivation occurs not only in the liver, but may also be local in tumor tissue characterized by an increased content of cytosolic hydrolytic enzymes.

Indications

Active ingredient

Composition

1 capsule contains:

Active substances:

Tegafur 400 mg.

Associates:

stearic acid.

Composition of the capsule shell:

gelatin,

titanium dioxide (E171),

How to take, the dosage

Administration orally.

The daily dose of Fluorafur® is 800-1000 mg/m2 (20-30 mg/kg body weight) in 2-4 doses, but not more than 2 g/day.

The course dose when taken orally is 30-40 g.

The interval between courses is 4 weeks.

The dose of Fluorafur® may be reduced in elderly patients and in the advanced stage of the disease.

Interaction

The simultaneous use of Fluorafur® and phenytoin may increase the effect of the latter.

Fluorafur® increases the effectiveness of other chemotherapeutic agents and radiation therapy (side effects are also increased).

Concomitant use with inhibitors of microsomal oxidation in the liver increases the toxicity of Fluorafur®.

Special Instructions

If it is necessary to prescribe the drug Fluorafur® to patients with disorders of hematopoiesis, hepatic and renal functions, glucose metabolism, with gastric and duodenal ulcer disease, susceptibility to hemorrhage, with infectious diseases, the potential risk of adverse reactions should be considered. During the treatment period it is necessary to monitor regularly the peripheral blood count, liver and kidney function status. The side effects of the drug increase with long-term use.

Dizziness, nausea and vomiting decrease with fractionation of the daily dose.

The drug should be discontinued if serious side effects develop.

Pediatric use

The safety of the drug in children has not been established.

Contraindications

Side effects

Blood system disorders: leukopenia, thrombocytopenia, anemia.

In the digestive system: nausea, vomiting, anorexia, abdominal pain, diarrhea; rarely – stomatitis, esophagitis, gastrointestinal mucosal ulcers, gastrointestinal bleeding, liver function disorders, acute hepatitis, acute pancreatitis.

CNS disorders: dizziness, confusion, somnolence, ataxia, euphoria, symptoms of leukoencephalitis.

Cardiovascular system disorders: cardialgia, angina pectoris, myocardial ischemia, myocardial infarction.

Sensory system disorders: diplopia, lacrimation, lacrimal duct fibrosis, loss of sense of smell.

Dermatological reactions: alopecia, disorders of skin regeneration, nails.

Others: pharyngitis, allergic reactions (including anaphylactic shock), renal dysfunction, dehydration of the body, interstitial pneumonia.

Overdose

Symptoms: aggravation of toxic effects on the gastrointestinal tract, CNS and suppression of hematopoiesis.

Treatment: control of hematopoiesis function for at least 4 weeks, if necessary symptomatic therapy is carried out.

The specific antidote to tegafur is unknown.

Pregnancy use

Fluorafur® is contraindicated in pregnancy and during lactation (breastfeeding).

Please note that the drug depresses the patient’s reproductive function.