Expected Reactions: Because cytarabine is a bone marrow suppressant, anemia, leukopenia, thrombocytopenia, megaloblastosis and reduced reticulocytes can be expected as a result of administration with cytarabine. The severity of these reactions are dose and schedule dependent. Cellular changes in the morphology of bone marrow and peripheral smears can be expected.
Following 5-day constant infusions or acute injections of 50 mg/m2 to 600 mg/m2, white cell depression follows a biphasic course. Regardless of initial count, dosage level, or schedule, there is an initial fall starting the first 24 hours with a nadir at days 7-9. This is followed by a brief rise which peaks around the twelfth day. A second and deeper fall reaches nadir at days 15-24. Then there is a rapid rise to above baseline in the next 10 days. Platelet depression is noticeable at 5 days with a peak depression occurring between days 12-15. Thereupon, a rapid rise to above baseline occurs in the next 10 days.
Infectious Complications: Infection: Viral, bacterial, fungal, parasitic or saprophytic infections, in any location in the body may be associated with the use of cytarabine alone or in combination with other immunosuppressive agents following immunosuppressant doses that affect cellular or humoral immunity. These infections may be mild, but can be severe and at times fatal.
The Cytarabine Syndrome: A cytarabine syndrome has been described by Castleberry. It is characterized by fever, myalgia, bone pain, occasionally chest pain, maculopapular rash, conjunctivitis and malaise. It usually occurs 6-12 hours following drug administration. Corticosteroids have been shown to be beneficial in treating or preventing the syndrome. If the symptoms of this syndrome are deemed treatable, corticosteroids should be contemplated as well as continuation of therapy with cytarabine.
Most Frequent Adverse Reactions: Anorexia, hepatic dysfunction, nausea, fever, vomiting, rash, diarrhea, thrombophlebitis, oral and anal inflammation or ulceration, bleeding (all sites). Nausea and vomiting are most frequent following rapid intravenous injection.
Less Frequent Adverse Reactions: Sepsis, abdominal pain, pneumonia, freckling, cellulitis at injection site, jaundice, skin ulceration, conjunctivitis (may occur with rash), urinary retention, dizziness, renal dysfunction, alopecia, neuritis, anaphylaxis (see WARNINGS), neural toxicity, allergic edema, sore throat, pruritus, esophageal ulceration, shortness of breath, esophagitis, urticaria, chest pain, pericarditis, headache, bowel necrosis, pancreatitis, sinus bradycardia.
Experimental Doses: Severe and at times fatal CNS, GI and pulmonary toxicity (different from that seen with conventional therapy regimens of cytarabine) has been reported following some experimental dose schedules of cytarabine. These reactions include reversible corneal toxicity and hemorrhagic conjunctivitis, which may be prevented or diminished by prophylaxis with a local corticosteroid eye drop; cerebral and cerebellar dysfunction, including personality changes, somnolence and coma, usually reversible; severe gastrointestinal ulceration, including pneumatosis cystoides intestinalis leading to peritonitis; sepsis and liver abscess; pulmonary edema, liver damage with increased hyperbilirubinemia; bowel necrosis; and necrotizing colitis. Rarely, severe skin rash, leading to desquamation has been reported. Complete alopecia is more commonly seen with experimental high dose therapy than with standard cytarabine treatment programs. If experimental high dose therapy is used, do not use a cytarabine injection containing benzyl alcohol.
Cases of cardiomyopathy with subsequent death has been reported following experimental high dose therapy with cytarabine in combination with cyclophosphamide when used for bone marrow transplant preparation. This cardiac toxicity may be schedule dependent.
A syndrome of sudden respiratory distress, rapidly progressing to pulmonary edema and radiographically pronounced cardiomegaly has been reported following experimental high dose therapy with cytarabine used for the treatment of relapsed leukemia from one institution in 16/72 patients. The outcome of this syndrome can be fatal.
Two patients with adult acute non-lymphocytic leukemia developed peripheral motor and sensory neuropathies after consolidation with high-dose cytarabine, daunorubicin, and asparaginase. Patients treated with high-dose cytarabine should be observed for neuropathy since dose schedule alterations may be needed to avoid irreversible neurologic disorders.
Ten patients treated with experimental intermediate doses of cytarabine (1 g/m2) with and without other chemotherapeutic agents (meta-AMSA, daunorubicin, etoposide) at various dose regimens developed a diffuse interstitial pneumonitis without clear cause that may have been related to the cytarabine.
Two cases of pancreatitis have been reported following experimental doses of cytarabine and numerous other drugs. Cytarabine could have been the causative agent.