Fdur (Floxuridine) - Description and Clinical Pharmacology

Sterile FDUR

(brand of floxuridine)

FOR INTRA-ARTERIAL INFUSION ONLY

R_x only

DESCRIPTION

Sterile FUDR (floxuridine), 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 an empirical formula of C₉H₁₁FN₂O₅. 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 246.19 and the structural formula is:

CLINICAL PHARMACOLOGY

When FUDR is given by rapid intra-arterial injection it is apparently rapidly catabolized to 5-fluorouracil. Thus, rapid injection of FUDR 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 FUDR is given by continuous intra-arterial infusion its direct anabolism to FUDR-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-bureidopropionic 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 FUDR are not available.