The major adverse effect of cytarabine is haematologic toxicity. Myelosuppression is normally manifested by megaloblastosis, leucopenia, anaemia, reticulocytopenia and thrombocytopenia. Leucopenia follows mainly from granulocyte depression; lymphocytes are minimally affected. The severity of these adverse effects is dependent on the dose of the drug and schedule of administration.Incidence and severity of haematologic toxicity is minimal after a single intravenous dose of cytarabine, but myelosuppression occurs in almost all patients with daily IV injections or continuous IV infusions of the drug.Nausea and vomiting may occur in patients on cytarabine therapy, and usually occur more frequently and severely following rapid IV administration as opposed to continuous infusion of the drug. Viral, bacterial, fungal parasitic or saprophytic infection which can be mild, severe and at times fatal, may be associated with the use of cytarabine when used alone or in combination with other immunosuppressive agents following immunosuppressive doses that affect cellular or humoral immunity.Neurotoxicity following intrathecal cytarabine has been associated with preservative containing diluents and many clinicians recommend the use of preservative free diluents instead.A cytarabine syndrome characterised by fever, myalgia, bone pain, malaise, maculopapular rash, conjunctivitis, and occasionally chest pain, has been reported. A "flu-like" syndrome has been reported, which may be treated with corticosteroid therapy if severe. Anaphylactoid reactions have occurred.It normally occurs at 6 to 12 hours after administration of the drug; corticosteroids have been shown to be of benefit in the treatment and prevention of the syndrome. If treatment of the symptoms of the syndrome is required, administration of corticosteroids should be considered, as well as continuation of cytarabine therapy.Two patients with adult non lymphocytic leukaemia developed peripheral motor and sensory neuropathies after consolidation with high dose cytarabine, daunorubicin and asparaginase. A syndrome of sudden respiratory distress, rapidly progressing to pulmonary oedema and radiologically pronounced cardiomegaly has been reported following experimental high dose therapy of cytarabine for relapsed leukaemia. This syndrome can have fatal consequences.
