Cyclophosphamide

5 WARNINGS AND PRECAUTIONS Myelosuppression, Immunosuppression, Bone Marrow Failure and Infections – Severe immunosuppression may lead to serious and sometimes fatal infections. Close hematological monitoring is required. ( 5.1 ) Urinary Tract and Renal Toxicity – Hemorrhagic cystitis, pyelitis, ureteritis, and hematuria can occur. Exclude or correct any urinary tract obstructions prior to treatment. ( 5.2 ) Cardiotoxicity – Myocarditis, myopericarditis, pericardial effusion, arrythmias and congestive heart failure, which may be fatal, have been reported. Monitor patients, especially those with risk factors for cardiotoxicity or pre-existing cardiac disease. ( 5.3 ) Pulmonary Toxicity – Pneumonitis, pulmonary fibrosis and pulmonary veno-occlusive disease leading to respiratory failure may occur. Monitor patients for signs and symptoms of pulmonary toxicity. ( 5.4 ) Secondary malignancies ( 5.5 ) Veno-occlusive Liver Disease - Fatal outcome can occur. ( 5.6 ) Embryo-Fetal Toxicity - Can cause fetal harm. Advise patients of potential risk to the fetus and to use effective contraception. ( 5.7 , 8.1 , 8.3 ) 5.1 Myelosuppression, Immunosuppression, Bone Marrow Failure and Infections Cyclophosphamide can cause myelosuppression (leukopenia, neutropenia, thrombocytopenia and anemia), bone marrow failure, and severe immunosuppression which may lead to serious and sometimes fatal infections, including sepsis and septic shock. Latent infections can be reactivated [see Adverse Reactions ( 6.2 )] . Antimicrobial prophylaxis may be indicated in certain cases of neutropenia at the discretion of the managing physician. In case of neutropenic fever, antibiotic therapy is indicated. Antimycotics and/or antivirals may also be indicated. Monitoring of complete blood counts is essential during cyclophosphamide treatment so that the dose can be adjusted, if needed. Cyclophosphamide should not be administered to patients with neutrophils ≤1,500/mm 3 and platelets < 50,000/mm 3 . Cyclophosphamide treatment may not be indicated, or should be interrupted, or the dose reduced, in patients who have or who develop a serious infection. G-CSF may be administered to reduce the risks of neutropenia complications associated with cyclophosphamide use. Primary and secondary prophylaxis with G-CSF should be considered in all patients considered to be at increased risk for neutropenia complications. The nadirs of the reduction in leukocyte count and thrombocyte count are usually reached in weeks 1 and 2 of treatment. Peripheral blood cell counts are expected to normalize after approximately 20 days. Bone marrow failure has been reported. Severe myelosuppression may be expected particularly in patients pretreated with and/or receiving concomitant chemotherapy and/or radiation therapy. 5.2 Urinary Tract and Renal Toxicity Hemorrhagic cystitis, pyelitis, ureteritis, and hematuria have been reported with cyclophosphamide. Medical and/or surgical supportive treatment may be required to treat protracted cases of severe hemorrhagic cystitis. Discontinue cyclophosphamide therapy in case of severe hemorrhagic cystitis. Urotoxicity (bladder ulceration, necrosis, fibrosis, contracture and secondary cancer) may require interruption of cyclophosphamide treatment or cystectomy. Urotoxicity can be fatal. Urotoxicity can occur with short-term or long-term use of cyclophosphamide. Before starting treatment, exclude or correct any urinary tract obstructions [see Contraindications ( 4 )] . Urinary sediment should be checked regularly for the presence of erythrocytes and other signs of urotoxicity and/or nephrotoxicity. Cyclophosphamide should be used with caution, if at all, in patients with active urinary tract infections. Aggressive hydration with forced diuresis and frequent bladder emptying can reduce the frequency and severity of bladder toxicity. Mesna has been used to prevent severe bladder toxicity. 5.3 Cardiotoxicity Myocarditis, myopericarditis, pericardial effusion including cardiac tamponade, and congestive heart failure, which may be fatal, have been reported with cyclophosphamide therapy. Supraventricular arrhythmias (including atrial fibrillation and flutter) and ventricular arrhythmias (including severe QT prolongation associated with ventricular tachyarrhythmia) have been reported after treatment with regimens that included cyclophosphamide. The risk of cardiotoxicity may be increased with high doses of cyclophosphamide, in patients with advanced age, and in patients with previous radiation treatment to the cardiac region and/or previous or concomitant treatment with other cardiotoxic agents. Particular caution is necessary in patients with risk factors for cardiotoxicity and in patients with pre-existing cardiac disease. Monitor patients with risk factors for cardiotoxicity and with pre-existing cardiac disease. 5.4 Pulmonary Toxicity Pneumonitis, pulmonary fibrosis, pulmonary veno-occlusive disease and other forms of pulmonary toxicity leading to respiratory failure have been reported during and following treatment with cyclophosphamide. Late onset pneumonitis (greater than 6 months after start of cyclophosphamide) appears to be associated with increased mortality. Pneumonitis may develop years after treatment with cyclophosphamide. Monitor patients for signs and symptoms of pulmonary toxicity. 5.5 Secondary Malignancies Cyclophosphamide is genotoxic [see Nonclinical Toxicology ( 13.1 )] . Secondary malignancies (urinary tract cancer, myelodysplasia, acute leukemias, lymphomas, thyroid cancer, and sarcomas) have been reported in patients treated with cyclophosphamide-containing regimens . The risk of bladder cancer may be reduced by prevention of hemorrhagic cystitis. 5.6 Veno-occlusive Liver Disease Veno-occlusive liver disease (VOD) including fatal outcome has been reported in patients receiving cyclophosphamide-containing regimens. A cytoreductive regimen in preparation for bone marrow transplantation that consists of cyclophosphamide in combination with whole-body irradiation, busulfan, or other agents has been identified as a major risk factor. VOD has also been reported to develop gradually in patients receiving long-term low-dose immunosuppressive doses of cyclophosphamide. Other risk factors predisposing to the development of VOD include preexisting disturbances of hepatic function, previous radiation therapy of the abdomen, and a low performance status. 5.7 Embryo-Fetal Toxicity Based on its mechanism of action and published reports of effects in pregnant patients or animals, cyclophosphamide capsules can cause fetal harm when administered to a pregnant woman [see Use in Specific Populations ( 8.1 ), Clinical Pharmacology ( 12.1 ) and Nonclinical Toxicology ( 13.1 )] . Exposure to cyclophosphamide during pregnancy may cause birth defects, miscarriage, fetal growth retardation, and fetotoxic effects in the newborn. cyclophosphamide is teratogenic and embryo-fetal toxic in mice, rats, rabbits and monkeys. Advise pregnant women and female patients of reproductive potential of the potential risk to the fetus [see Use in Specific Populations ( 8.1 )] . Verify the pregnancy status of females of reproductive potential prior to initiation of cyclophosphamide capsules. Advise females of reproductive potential to use effective contraception during treatment with cyclophosphamide capsules and for up to 1 year after completion of therapy. Advise male patients with female partners of reproductive potential to use effective contraception during treatment with cyclophosphamide capsules and for 4 months after completion of therapy [see Use in Specific Populations ( 8.1 , 8.3 )] . 5.8 Infertility Male and female reproductive function and fertility may be impaired in patients being treated with cyclophosphamide capsules. Cyclophosphamide interferes with oogenesis and spermatogenesis. It may cause sterility in both sexes. Development of sterility appears to depend on the dose of cyclophosphamide, duration of therapy, and the state of gonadal function at the time of treatment. Cyclophosphamide-induced sterility may be irreversible in some patients. Advise patients on the potential risks for infertility [see Use in Specific Populations ( 8.3 and 8.4 )] . 5.9 Impairment of Wound Healing Cyclophosphamide may interfere with normal wound healing. 5.10 Hyponatremia Hyponatremia associated with increased total body water, acute water intoxication, and a syndrome resembling SIADH (syndrome of inappropriate secretion of antidiuretic hormone), which may be fatal, has been reported.