WARNINGS
Anaphylactic Reactions, Cross-sensitivity with Other Alkylating Agents
Anaphylactic reactions including those with fatal outcomes have been reported in association with cyclophosphamide. Possible cross-sensitivity with other alkylating agents has been reported.
Myelosuppression, Immunosuppression, Infections Treatment with cyclophosphamide may cause myelosuppression (anaemia, leukopenia, neutropenia and thrombocytopenia) and significant suppression of immune responses, which may result in severe, sometimes fatal, infections, sepsis and septic shock. Infections reported with cyclophosphamide include pneumonias, as well as other bacterial, fungal, viral, protozoal, and parasitic infections.
Latent infections can be reactivated. Reactivation has been reported for various bacterial, fungal, viral, protozoal, and parasitic infections.
Infections occurring during treatment with cyclophosphamide, including neutropenic fever, must be treated appropriately. Antimicrobial prophylaxis may be indicated in certain cases of neutropenia (at the discretion of the managing physician). In case of neutropenic fever, antibiotics and/or antimycotics must be given. Cyclophosphamide must be administered with the necessary caution (or not at all) in patients with severe
functional impairment of
bone marrow and patients with severe immunosuppression.
Close haematological monitoring is required for all patients during treatment. Haematological parameters must be checked prior to each administration and regularly during treatment. More frequent monitoring may be required if leukocyte counts drop below 3000 cells/microlitre (cells/mm³). Dose adjustment due to myelosuppression is recommended (see section 4.2).
Unless essential, cyclophosphamide should not be administered to patients with a leukocyte count below 2500 cells/microlitre (cells/ mm
3) and/or a platelet count below 50,000 cells/microlitre (cells/mm
3).
In principle, the fall in the peripheral blood cell and thrombocyte count and the time taken to recover may increase with increasing doses of cyclophosphamide.
The nadirs of the reduction in leukocyte count and thrombocyte count are usually reached in weeks 1 and 2 of treatment. The bone marrow recovers relatively quickly, and the levels of peripheral blood cell counts normalize, as a rule, after approximately 20 days.
Cyclophosphamide treatment may not be indicated, or should be interrupted, or the dose reduced, in patients who have or who develop a serious infection.
Severe myelosuppression must be expected particularly in patients pre-treated with and/or receiving concomitant chemotherapy and/or radiation therapy.
Urinary Tract and Renal Toxicity
Hemorrhagic cystitis, pyelitis, ureteritis, and haematuria have been reported with cyclophosphamide therapy. Bladder ulceration/necrosis, fibrosis/contracture and secondary cancer may develop. Urotoxicity may mandate interruption of treatment. Cases of urotoxicity with fatal outcomes have been reported.
Urotoxicity can occur with short-term and long-term use of cyclophosphamide. Hemorrhagic cystitis after single doses of cyclophosphamide has been reported. Cystectomy may become necessary due to fibrosis, bleeding, or secondary malignancy. Past or concomitant radiation or busulfan treatment may increase the risk for cyclophosphamide-induced hemorrhagic cystitis. Cystitis is, in general, initially abacterial. Secondary bacterial colonisation may follow.
Before starting treatment, it is necessary to exclude or correct any urinary tract obstructions. See section 4.3. Urinary sediment should be checked regularly for the presence of erythrocytes and other signs of uro/nephrotoxicity. Adequate treatment with mesna and/or strong hydration to force diuresis can markedly reduce the frequency and severity of bladder toxicity. It is important to ensure that patients empty the bladder at regular intervals. Haematuria usually resolves in a few days after cyclophosphamide treatment is stopped, but it may persist. Severe hemorrhagic cystitis usually requires a discontinuation of the treatment with cyclophosphamide.
Cyclophosphamide has also been associated with nephrotoxicity, including renal tubular necrosis.
Hyponatremia associated with increased total body water, acute water intoxication, and a syndrome resembling SIADH (syndrome of inappropriate secretion of antidiuretic hormone) have been reported in association with cyclophosphamide administration. Fatal outcomes have been reported.
Cardiotoxicity, Use in Patients with Cardiac Disease Myocarditis and myopericarditis, which may be accompanied by significant pericardial effusion and cardiac tamponade, have been reported with cyclophosphamide therapy and have led to severe, sometimes fatal congestive heart failure. Histopathologic examination has primarily shown hemorrhagic myocarditis. Haemopericardium has been reported secondary to hemorrhagic myocarditis and myocardial necrosis. Acute cardiac toxicity has been reported with single doses as low as 20 mg/kg of cyclophosphamide.
Following exposure to treatment regimens that included cyclophosphamide, supraventricular arrhythmias (including atrial fibrillation and flutter) as well as ventricular arrhythmias (including severe QT prolongation associated with ventricular tachyarrhythmia) have been reported in patients with and without other signs of cardiotoxicity.
The risk of cyclophosphamide cardiotoxicity as a result of treatment with cyclophosphamide may, for example, be increased following high doses of cyclophosphamide, in patients with advanced age, and in patients with previous radiation treatment of the cardiac region and/or previous or concomitant treatment with other cardiotoxic agents. See section 4.5.
Particular caution is required in patients with risk factors for cardiotoxicity and in patients with a pre-existing cardiac disease.
Pulmonary Toxicity
Pneumonitis and pulmonary fibrosis have been reported during and following treatment with cyclophosphamide. Pulmonary veno-occlusive disease and other forms of pulmonary toxicity have also been reported. Pulmonary toxicity leading to respiratory failure has been reported. While the incidence of cyclophosphamide-associated pulmonary toxicity is low, prognosis for affected patients is poor. Late onset of pneumonitis (greater than 6 months after start of cyclophosphamide) appears to be associated with a particularly high mortality. Pneumonitis may develop even years after treatment with cyclophosphamide. Acute pulmonary toxicity has been reported after a single cyclophosphamide dose.
Secondary Malignancies
As with all cytotoxic therapy, treatment with cyclophosphamide involves the risk of secondary tumours and their precursors as sequelae.
The risk of urinary tract cancer as well as the risk of myelodysplastic alterations, partly progressing to acute leukemias, is increased. Other malignancies reported after use of cyclophosphamide or regimens with cyclophosphamide include lymphomas, thyroid cancer, and sarcomas.
In some cases, the second malignancy developed several years after cyclophosphamide treatment had been discontinued. Malignancy has also been reported after in utero exposure.
The risk of bladder cancer can be markedly reduced by hemorrhagic cystitis prophylaxis.
Veno-occlusive Liver DiseaseVeno-occlusive liver disease (VOLD) has been reported in patients receiving cyclophosphamide, mainly in patients receiving a cytoreductive regimen in preparation for bone marrow transplantation in combination with whole-body irradiation, busulfan, or other agents (see section 4.5). After cytoreductive therapy, the clinical syndrome typically develops 1 to 2 weeks after transplantation and is characterized by sudden weight gain, painful hepatomegaly, ascites, and hyperbilirubinemia/jaundice. However, VOLD has also been reported to develop gradually in patients receiving long-term low-dose immunosuppressive doses of cyclophosphamide.
As a complication of VOLD, hepatorenal syndrome and multiorgan failure may develop. Fatal outcome of cyclophosphamide-associated VOLD has been reported. Risk factors predisposing a patient to the development of VOLD include pre-existing disturbances of hepatic function, previous radiation therapy of the abdomen, and a low performance score.
VOLD incidence has been reported to reduce, if a time interval of at least 24 hours is observed between the last administration of busulfan and the first administration of cyclophosphamide (see section 4.2 and 4.5).
Genotoxicity
Cyclophosphamide is genotoxic and mutagenic, both in somatic and in male and female germ cells. Therefore, women should not become pregnant and men should not father a child during therapy with cyclophosphamide.
Women should not become pregnant during the treatment and for a period of 12 months following discontinuation of the therapy.
Men should not father a child during the treatment and for a period of 6 months following discontinuation of the therapy
Animal data indicate that exposure of oocytes during follicular development may result in a decreased rate of implantations and viable pregnancies, and in an increased risk of malformations. This effect should be considered in case of intended fertilisation or pregnancy after discontinuation of cyclophosphamide therapy. The exact duration of follicular development in humans is not known, but may be longer than 12 months. Sexually active women and men should use effective methods of contraception during these periods of time (see section 4.6.).
Fertility
Cyclophosphamide interferes with oogenesis and spermatogenesis. It may cause sterility in both sexes. Men treated with cyclophosphamide should be informed about sperm preservation prior to treatment (see section 4.6).
Impairment of Wound Healing
Cyclophosphamide may interfere with normal wound healing.
PRECAUTIONS
Alopecia
Alopecia has been reported and may occur more commonly with increasing doses. Alopecia may progress to baldness. The hair can be expected to grow back after treatment with the drug or even during continued drug treatment, though it may be different in texture or colour.
Nausea and Vomiting
Administration of cyclophosphamide may cause nausea and vomiting. Current guidelines on the use of antiemetics for prevention and amelioration of nausea and vomiting should be considered.
Alcohol consumption may increase cyclophosphamide-induced vomiting and nausea.
Stomatitis
Administration of cyclophosphamide may cause stomatitis (oral mucositis). Current guidelines on measures for prevention and amelioration of stomatitis should be considered.
Paravenous Administration The cytostatic effect of cyclophosphamide occurs after its activation, which takes place mainly in the liver. Therefore, the risk of tissue injury from accidental paravenous administration is low.
In case of accidental paravenous administration of cyclophosphamide, the infusion should be stopped immediately, the extravascular cyclophosphamide solution should be aspirated with the cannula in place, and other measures should be instituted as appropriate. The area should subsequently be rinsed with physiological saline solution, and the arm or leg should rest.
Use in Patients with Renal Impairment
In patients with renal impairment, particularly in patients with severe renal impairment, decreased renal excretion may result in increased plasma levels of cyclophosphamide and its metabolites. This may result in increased toxicity and should be considered when determining the dosage in such patients. See section 4.2.
Use in Patients with Hepatic Impairment
Severe hepatic impairment may be associated with a decreased effect of cyclophosphamide. This may negatively alter the effectiveness of cyclophosphamide treatment and should be considered when selecting the dose and interpreting response to the dose selected. See section 4.2. Due to the porphyrogenic effect of Cycolphosphamide patients with acute porphyria should be treated with caution.
Use in Adrenalectomised Patients
Patients with adrenal insufficiency may require an increase in corticoid substitution dose when exposed to stress from toxicity due to cytostatics, including cyclophosphamide.
Use in Patients with Diabetes Mellitus
Caution is also advised in is patients with diabetes mellitus, since cyclophosphamide may interact with insulin and other hypoglycaemic agents (also see section 4.5).
Use in Patients who have recently undergone surgery
In general, cytostatics (among which agents cyclophosphamide) should not be administered to patients who had a surgery less than 10 days ago.