Dexrazoxane hydrochloride

Description

Dexrazoxane hydrochloride is a cytoprotective agent which is hydrolysed to an active metabolite that chelates iron within cells.
It is used (as Cardioxane) to reduce the cardiotoxicity of doxorubicin and other anthracyclines. It actively chelates iron within cells, thus preventing the formation of the anthracycline--iron complex that is thought to cause cardiotoxicity.
It is also use (as Savene) in the management of anthracycline extravasation, where its action is to inhibit the enzyme topoisomerase II.

Biological Activity

Dexrazoxane hydrochloride is a topoisomerase II inhibitor and intracellular ion chelator. Bridges and stabilizes an interface between two ATPase promoters to inhibit topoisomerase II activity. Cardioprotective when co-administered with doxorubicin; decreases formation of reactive oxygen species (ROS) and activates the PI3K/Akt survival pathway.

ZINECARD

ZINECARD® (dexrazoxane for injection) is a sterile, pyrogen-free lyophilizate intended for intravenous administration. It is a cardioprotective agent for use in conjunction with doxorubicin.
Dexrazoxane, a potent intracellular chelating agent is a derivative of EDTA. Dexrazoxane is a whitish crystalline powder that melts at 191° to 197°C. It is sparingly soluble in water and 0.1 N HCl, slightly soluble in ethanol and methanol, and practically insoluble in nonpolar organic solvents. The pKa is 2.1. Dexrazoxane has an octanol/water partition coefficient of 0.025 and degrades rapidly above a pH of 7.0.
ZINECARD is available in 250 mg and 500 mg single use only vials. ZINECARD must be reconstituted with Sterile Water for Injection, USP.
Each 250 mg vial contains dexrazoxane hydrochloride equivalent to 250 mg dexrazoxane. Hydrochloric Acid, NF is added for pH adjustment.. When reconstituted as directed with 25 mL of Sterile Water for Injection, USP, each mL contains: 10 mg dexrazoxane. The pH of the resultant solution is 1.0 to 3.0.

Mechanism of action

As a derivative of EDTA, dexrazoxane chelates iron and thus reduces the number of metal ions complexed with anthracycline and, consequently, decrease the formation of superoxide radicals. The exact chelation mechanism is unknown, but it has been postulated that dexrazoxane can be converted into ring-opened form intracellularly and interfere with iron-mediated free radical generation that is in part thought to be responsible for anthryacycline induced cardiomyopathy. It was speculated that dexrazoxane could be used for further investigation to synthesize new antimalarial drugs.

in vivo

Uses

Dexrazoxane is used to reduce the risk and severity of heart damage caused by doxorubicin treatment and similar cancer chemotherapy medications. Heart damage limits the length of time you can be treated with doxorubicin. Dexrazoxane allows you to continue doxorubicin treatment for longer. When used for this purpose, dexrazoxane treatment is usually started after you have received several doses of doxorubicin. It is usually not given with the first doses of doxorubicin since doing so may reduce the effectiveness of doxorubicin.