5 WARNINGS AND PRECAUTIONS
ZINECARD may add to the myelosuppression caused by chemotherapeutic agents. Obtain a complete blood count prior to and during each course of therapy, and administer ZINECARD and chemotherapy only when adequate hematologic parameters are met.
5.2 Concomitant Chemotherapy
Only use ZINECARD in those patients who have received a cumulative doxorubicin dose of 300 mg/m2 and are continuing with doxorubicin therapy. Do not use with chemotherapy initiation as ZINECARD may interfere with the antitumor activity of the chemotherapy regimen. In a trial conducted in patients with metastatic breast cancer who were treated with fluorouracil, doxorubicin, and cyclophosphamide (FAC) with or without ZINECARD starting with their first cycle of FAC therapy, patients who were randomized to receive ZINECARD had a lower response rate (48% vs. 63%) and shorter time to progression than patients who were randomized to receive placebo.
5.3 Cardiac Toxicity
Treatment with ZINECARD does not completely eliminate the risk of anthracycline-induced cardiac toxicity. Monitor cardiac function before and periodically during therapy to assess left ventricular ejection fraction (LVEF). In general, if test results indicate deterioration in cardiac function associated with doxorubicin, the benefit of continued therapy should be carefully evaluated against the risk of producing irreversible cardiac damage.
5.4 Secondary Malignancies
Secondary malignancies such as acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) have been reported in studies of pediatric patients who have received ZINECARD in combination with chemotherapy. ZINECARD is not indicated for use in pediatric patients. Some adult patients who received ZINECARD in combination with anti-cancer agents known to be carcinogenic have also developed secondary malignancies, including AML and MDS.
Razoxane is the racemic mixture, of which dexrazoxane is the S(+)-enantiomer. Secondary malignancies (primarily acute myeloid leukemia) have been reported in patients treated chronically with oral razoxane. In these patients, the total cumulative dose of razoxane ranged from 26 to 480 grams and the duration of treatment was from 42 to 319 weeks. One case of T-cell lymphoma, one case of B-cell lymphoma, and six to eight cases of cutaneous basal cell or squamous cell carcinoma have also been reported in patients treated with razoxane. Long-term administration of razoxane to rodents was associated with the development of malignancies [see Nonclinical Toxicology (13.1)].
5.5 Embryo-Fetal Toxicity
ZINECARD can cause fetal harm when administered to pregnant women. Dexrazoxane administration during the period of organogenesis resulted in maternal toxicity, embryotoxicity and teratogenicity in rats and rabbits at doses significantly lower than the clinically recommended dose [see Use in Specific Populations (8.1)]. If this drug is used during pregnancy, or if the patient becomes pregnant while taking this drug, the patient should be apprised of the potential hazard to a fetus.
Advise female patients of reproductive potential to avoid becoming pregnant and to use highly effective contraception during treatment [see Use in Specific Populations (8.6)].