| Single doses will produce a leucopenia which may be severe but usually returns to normal within 21 days.Depression of the reticuloendothelial system with granulopoiesis and lymphopoiesis being more affected than thrombopoiesis and erythropoiesis. This depression, however, is reversible.Amenorrhoea and azoospermia often occur during treatment with cyclophosphamide but in most cases are reversible.Haematuria may occur during or after therapy with Cyclophosphamide. Cyclophosphamide is excreted mainly in the urine, largely in the form of active metabolites which may give rise to a chemical cystitis which may be haemorrhagic. Acute sterile haemorrhagic cystitis may occur in up to 10% of patients not given mesna (Uromitexan) in conjunction with Cyclophosphamide. Late sequelae of this cystitis are bladder contracture and fibrosis.Because of this, a high fluid intake should be maintained with frequent emptying of the bladder. Cyclophosphamide therapy may lead to inappropriate secretion of anti-diuretic hormone, fluid retention and hyponatremia, with subsequent water intoxication. Should this arise, a diuretic may be given. Cyclophosphamide may cause myocardial toxicity, especially at high dosage.Cyclophosphamide may induce permanent sterility in children.In addition to those noted above, the following may accompany cyclophosphamide therapy: hair loss, which may be total, although generally reversible; mucosal ulcertation; anorexia, nausea and vomiting; pigmentation, typically affecting the palms and nails of the hands and the soles of the feet, and interstitial pulmonary fibrosis.Hepatic toxicity has rarely been reported.Cyclophosphamide has been shown to be mutagenic, teratogenic, and carcinogenic in certain laboratory tests and as with other cytotoxic agents, there have been reports of possible drug-induced neoplasia. There is an excessive risk of acute leukaemia and bladder cancer following cyclophosphamide therapy.An alteration in carbohydrate metabolism may be seen in patients on cyclophosphamide. Other side effects, such as pancreatitis, macrocytosis, and induction of hyperglycaemia or hypoglycaemia have been reported.There are certain complications such as veno-occlusive disease, thromboembolism, disseminated intravascular coagulation or haemolytic uraemic syndrome, that may also be induced by the underlying disease, but which might occur with an increased frequency during chemotherapy that includes cyclophosphamide.Side effects have occasionally occurred after cessation of therapy. | |