FLOXURIDINE- floxuridine injection, powder, lyophilized, for solution
Hikma Pharmaceuticals USA Inc.
FOR INTRA-ARTERIAL INFUSION ONLY
It is recommended that floxuridine be given only by or under the supervision of a qualified physician who is experienced in cancer chemotherapy and intra-arterial drug therapy and is well versed in the use of potent antimetabolites.
Because of the possibility of severe toxic reactions, all patients should be hospitalized for initiation of the first course of therapy.
Floxuridine for Injection, USP, an antineoplastic antimetabolite, is available as a sterile, nonpyrogenic, lyophilized powder for reconstitution. Each vial contains 500 mg of floxuridine which is to be reconstituted with 5 mL of sterile water for injection. An appropriate amount of reconstituted solution is then diluted with a parenteral solution for intra-arterial infusion (see DOSAGE AND ADMINISTRATION section).
Floxuridine is a fluorinated pyrimidine. Chemically, floxuridine is 2′-Deoxy-5-fluorouridine, with a molecular formula of C9 H11 FN2 O5 . It is a white to off-white odorless solid which is freely soluble in water.
The 2% aqueous solution has a pH of between 4.0 and 5.5. The molecular weight of floxuridine is 246.20 and the structural formula is:structural formula
When floxuridine is given by rapid intra-arterial injection it is apparently rapidly catabolized to 5-fluorouracil. Thus, rapid injection of floxuridine produces the same toxic and antimetabolic effects as does 5-fluorouracil. The primary effect is to interfere with the synthesis of deoxyribonucleic acid (DNA) and to a lesser extent inhibit the formation of ribonucleic acid (RNA). However, when floxuridine is given by continuous intra-arterial infusion its direct anabolism to floxuridine-monophosphate is enhanced, thus increasing the inhibition of DNA.
Floxuridine is metabolized in the liver. The drug is excreted intact and as urea, fluorouracil, a-fluoro-b-ureidopropionic acid, dihydrofluorouracil, a-fluoro-b-guanidopropionic acid and a-fluoro-b-alanine in the urine; it is also expired as respiratory carbon dioxide. Pharmacokinetic data on intra-arterial infusion of floxuridine are not available.
Floxuridine for Injection, USP is effective in the palliative management of gastrointestinal adenocarcinoma metastatic to the liver, when given by continuous regional intra-arterial infusion in carefully selected patients who are considered incurable by surgery or other means. Patients with known disease extending beyond an area capable of infusion via a single artery should, except in unusual circumstances, be considered for systemic therapy with other chemotherapeutic agents.
Floxuridine therapy is contraindicated for patients in a poor nutritional state, those with depressed bone marrow function or those with potentially serious infections.
BECAUSE OF THE POSSIBILITY OF SEVERE TOXIC REACTIONS, ALL PATIENTS SHOULD BE HOSPITALIZED FOR THE FIRST COURSE OF THERAPY.
Floxuridine should be used with extreme caution in poor risk patients with impaired hepatic or renal function or a history of high-dose pelvic irradiation or previous use of alkylating agents. The drug is not intended as an adjuvant to surgery.
Floxuridine may cause fetal harm when administered to a pregnant woman. It has been shown to be teratogenic in the chick embryo, mouse (at doses of 2.5 to 100 mg/kg) and rat (at doses of 75 to 150 mg/kg). Malformations included cleft palates; skeletal defects; and deformed appendages, paws and tails. The dosages which were teratogenic in animals are 4.2 to 125 times the recommended human therapeutic dose.
There are no adequate and well-controlled studies with floxuridine in pregnant women. If this drug is used during pregnancy or if the patient becomes pregnant while taking (receiving) this drug, the patient should be apprised of the potential hazard to the fetus. Women of childbearing potential should be advised to avoid becoming pregnant.
Any form of therapy which adds to the stress of the patient, interferes with nutrition or depresses bone marrow function will increase the toxicity of floxuridine.
Floxuridine is a highly toxic drug with a narrow margin of safety. Therefore, patients should be carefully supervised since therapeutic response is unlikely to occur without some evidence of toxicity. Severe hematological toxicity, gastrointestinal hemorrhage and even death may result from the use of floxuridine despite meticulous selection of patients and careful adjustment of dosage. Although severe toxicity is more likely in poor risk patients, fatalities may be encountered occasionally even in patients in relatively good condition.
Therapy is to be discontinued promptly whenever one of the following signs of toxicity appears:
- Myocardial ischemia
- Stomatitis or esophagopharyngitis, at the first visible sign
- Leukopenia (WBC under 3500) or a rapidly falling white blood count
- Vomiting, intractable
- Diarrhea, frequent bowel movements or watery stools
- Gastrointestinal ulceration and bleeding
- Thrombocytopenia (platelets under 100,000)
- Hemorrhage from any site
Patients should be informed of expected toxic effects, particularly oral manifestations. Patients should be alerted to the possibility of alopecia as a result of therapy and should be informed that it is usually a transient effect.
Careful monitoring of the white blood count and platelet count is recommended.
See WARNINGS section.
Long-term studies in animals to evaluate the carcinogenic potential of floxuridine have not been conducted. On the basis of the available data, no evaluation can be made of the carcinogenic risk of floxuridine to humans.
Oncogenic transformation of fibroblasts from mouse embryo has been induced in vitro by floxuridine, but the relationship between oncogenicity and mutagenicity is not clear. Floxuridine has also been shown to be mutagenic in human leukocytes in vitro and in the Drosophila test system. In addition, 5-fluorouracil, to which floxuridine is catabolized when given by intra-arterial injection, has been shown to be mutagenic in in vitro tests.
The effects of floxuridine on fertility and general reproductive performance have not been studied in animals. However, because floxuridine is catabolized to 5-fluorouracil, it should be noted the 5-fluorouracil has been shown to induce chromosomal aberrations and changes in chromosome organization of spermatogonia in rats at doses of 125 or 250 mg/kg, administered intraperitoneally.
Spermatogonial differentiation was also inhibited by fluorouracil, resulting in transient infertility. In female rats, fluorouracil, administered intraperitoneally at doses of 25 or 50 mg/kg during the preovulatory phase of oogenesis, significantly reduced the incidence of fertile matings, delayed the development of pre- and post-implantation embryos, increased the incidence of preimplantation lethality and induced chromosomal anomalies in these embryos. Compounds such as floxuridine, which interfere with DNA, RNA and protein synthesis, might be expected to have adverse effects on gametogenesis.
See WARNINGS section. Floxuridine has been shown to be teratogenic in the chick embryo, mouse (at doses of 2.5 to 100 mg/kg) and rat (at doses of 75 to 150 mg/kg). Malformations included cleft palates, skeletal defects and deformed appendages, paws and tails. The dosages which were teratogenic in animals were 4.2 to 125 times the recommended human therapeutic dose.
There are no adequate and well-controlled studies with floxuridine in pregnant women. While there is no evidence of teratogenicity in humans due to floxuridine, it should be kept in mind that other drugs which inhibit DNA synthesis (e.g., methotrexate and aminopterin) have been reported to be teratogenic in humans. Floxuridine should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.
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