warnings
Warnings and Precautions: Experience with large cumulative doses of liposomal doxorubicin is very limited. Liposomal doxorubicin’s cardiac risk and its risk compared to conventional doxorubicin formulations have not been adequately evaluated. At present, therefore, the warnings related to the use of conventional formulations of doxorubicin should be observed. It is recommended that all patients receiving liposomal doxorubicin routinely undergo frequent ECG monitoring. Transient ECG changes such as, T-wave flattening, S-T segment depression and benign arrhythmias are not considered mandatory indications for the suspension of liposomal doxorubicin therapy. However, reduction of the QRS complex is considered more indicative of cardiac toxicity. If this change occurs, the most definitive test for anthracycline myocardial injury i.e., endomyocardial biopsy, must be considered. More specific methods for the evaluation and monitoring of cardiac functions as compared to ECG are a measurement of left ventricular ejection fraction by echocardiography or preferably by multigated angiography (MUGA). These methods must be applied routinely before the initiation of liposomal doxorubicin therapy and repeated periodically during treatment. The evaluation of left ventricular function is considered to be mandatory before each additional administration of liposomal doxorubicin that exceeds a lifetime cumulative anthracycline dose of 450 mg/m 2 . Whenever cardiomyopathy is suspected i.e., the left ventricular ejection fraction has substantially decreased relative to pretreatment values and/or left ventricular ejection fraction is lower than a prognostically relevant value (e.g., < 45%), endomyocardial biopsy may be considered and the benefit of continued therapy must be carefully evaluated against the risk of developing irreversible cardiac damage. The evaluation tests and methods mentioned above concerning the monitoring of cardiac performance during anthracycline therapy are to be employed in the following order: ECG monitoring, measurement of left ventricular ejection fraction, endomyocardial biopsy. If a test result indicates possible cardiac injury associated with liposomal doxorubicin therapy, the benefit of continued therapy must be carefully weighed against the risk of myocardial injury. Caution should be observed in patients who have received other anthracyclines and the total dosage of doxorubicin hydrochloride given should take into account any previous or concomitant therapy with other anthracyclines or related compounds. Cardiac toxicity may also occur at cumulative anthracycline doses lower than 450 mg/m 2 in patients with prior mediastinal irradiation or in those receiving concurrent cyclophosphamide therapy. Congestive cardiac failure due to cardiomyopathy may occur suddenly, without prior ECG changes and may also be encountered several weeks after discontinuation of therapy. Patients with a history of cardiovascular disease should be administered liposomal doxorubicin only when the potential benefit of treatment outweighs the risk. Acute infusion related reactions characterized by flushing, shortness of breath, facial swelling, headache, chills, chest pain, back pain, tightness in the chest and throat, fever, tachycardia, pruritus, rash, cyanosis, syncope, bronchospasm, asthma, apnea and/or hypotension have been reported with liposomal doxorubicin. In most patients these reactions resolve over the course of several hours to a day once the infusion is terminated or when the rate of infusion is slowed. Liposomal doxorubicin should be administered at the initial rate of 1 mg/min to minimize the risk of infusion reactions. Serious and sometimes life threatening or fatal allergic/anaphylactoid like infusion reactions have been reported. Medications to treat such reactions and emergency equipment should be available for immediate use. Moderate and reversible myelosupression has been observed in ovarian and breast cancer patients who received liposomal doxorubicin with anemia being the most common hematologic adverse event followed by leucopenia, thrombocytopenia and neutropenia. Myelosuppression can be a dose limiting adverse event in patients with AIDS associated with Kaposi s sarcoma who already present with baseline myelosuppression. Again leucopenia seemed to be the most common haematological adverse event in this population. Because of the potential for bone marrow suppression, careful hematologic monitoring including white blood cell, neutrophil, platelet counts and hemoglobin/hematocrit should be done. Hematologic toxicity may require dose reduction or delay or suspension of therapy. Persistent severe myelosuppression may result in superinfection, neutropenic fever or hemorrhage. Development of sepsis in the setting of neutropenia has resulted in the discontinuation of treatment and in rare cases death. Hematologic toxicity may be more severe when liposomal doxorubicin is administered in combination with other agents that cause bone marrow suppression. Dosage should be reduced in patients with impaired hepatic function. Prior to liposomal doxorubicin administration evaluation of hepatic function is recommended using conventional clinical laboratory tests such as SGOT, SGPT, alkaline phosphatase and bilirubin. Radiation induced toxicity to the myocardium, mucosae, skin and liver have been reported to be increased by the administration of doxorubicin HCl. Given the difference in pharmacokinetic profiles and dosing schedules, liposomal doxorubicin should not be used interchangeably with other formulations of doxorubicin hydrochloride.