Captabine® (Capecitabine USP), is a fluoropyrimidine carbamate with antineoplastic activity. It is an orally administered systemic prodrug of 5′-deoxy-5-fluorouridine (5′-DFUR) which is converted to 5-fluorouracil. The chemical name for Captabine is 5′-deoxy 5-fluoro-N-[(pentyloxy) carbonyl]-cytidine. Capecitabine is a white to off-white crystalline powder with an aqueous solubility of 26 mg/mL at 20°C. Its molecular weight is 359.35 and the following structural formula is:
Each film coated tablet contains Capecitabine USP 150 mg & 500 mg. Mechanism of action Enzymes convert capecitabine to 5-fluorouracil (5-FU) in vivo. Both normal and tumor cells metabolize 5-FU to 5-fluoro-2′-deoxyuridine monophosphate (FdUMP) and 5-fluorouridine triphosphate (FUTP). These metabolites cause cell injury by two different mechanisms. First, FdUMP and the folate cofactor, N5-10 methylenetetrahydrofolate,
binds to thymidylate synthase (TS) to form a covalently bound ternary complex. This inhibits the formation of thymidylate which is a necessary precursor of thymidine triphosphate in DNA synthesis. Thus it causes inhibition of cell division. Second, nuclear transcriptional enzymes can mistakenly incorporate FUTP in place of uridine triphosphate
(UTP) during RNA synthesis. This metabolic error can interfere with RNA processing and protein synthesis.7 Tab. Antimetabolite 8
Protein binding <60%
Half-life 38–45 minutes
Excretion Renal 95.5%, fecal 2.6%
Captabine® is indicated as a single agent for adjuvant treatment in patients with Dukes’ C colon cancer who have undergone complete resection of the primary tumor when treatment with fluoropyrimidine therapy alone is preferred. It is indicated as first-line treatment of patients with metastatic colorectal carcinoma when treatment with
fluoropyrimidine therapy alone is preferred.
Captabine® in combination with docetaxel is indicated for the treatment of patients with metastatic breast cancer after failure of prior anthracycline-containing chemotherapy. Monotherapy is also indicated for the treatment of patients with metastatic breast cancer
resistant to both paclitaxel and an anthracycline-containing chemotherapy regimen or resistant to paclitaxel and for whom further anthracycline therapy is not indicated.
Captabine® is indicated for the first line treatment of patients with locally advanced and metastatic pancreatic cancer in combination with gemcitabine.
Oesophagogastric Cancer: Captabine® is indicated for the first line treatment of patients with advanced oesophagogastric cancer.
Dosage and administration
Oral administration of 1.25 g/m2 twice daily for 14 days, followed by a 7-day interval, given as 3-week cycles for a total 8 cycles in case of stage-lll colon cancer and locally advanced or metastatic breast cancer. For metastatic colorectal cancer, in combination therapy it is administered orally as 0.8-1 g/m2 twice daily for 14 days repeated after 7 days interval.
Possible side effects
Cardiovascular: (myocardial infarction, angina). Dermatological: hand-foot syndrome (numbness, tingling, pain, redness, or blistering of the palms of the hands and soles of the feet). This can lead to the disappearance of fingerprints in some patients. Gastrointestinal: diarrhea (sometimes severe), nausea, stomatitis. Hematological: neutropenia, anemia, thrombocytopenia. Hepatic: Hyperbilirubinemia.
Capecitabine is contraindicated in patients with known dihydropy rimidine dehydrogenase (DPD) deficiency, it is also contraindicated in patients with severe renal impairment (creatinine clearance below 30 mL/min), and in patients with known hypersensitivity to
May interact with warfarin and increase bleeding risk. May inhibit CYP2C9 enzyme, and therefore increase levels of substrates such as phenytoin and other substrates of CYP2C9 enzymes. The concomitant use of leucovorin is not recommended as it increases the toxicity of capecitabine without any apparent advantage in response rate.
Patients receiving therapy with capecitabine should be monitored by a physician experienced in the use of cancer chemotherapeutic agents. Most adverse reactions are reversible and do not need to result in discontinuation, although doses may need to be withheld or reduced. During therapy, tablets should not be broken to adjust the dose.
Product should be stored at a dry place of controlled room temperature below 30oC and kept out of the reach of children.
Captabine® 500 mg tablet.: Each box contains 3×10 tablets in blister pack.