Cytarabine
(ARA-C, Cytosine arabinoside)
Cytarabine (Cytosar-U)
ARA-C (Cytosar-U)
Cytosine arabinoside (Cytosar-U)
Cytarabine
(sye- TAIR-ah-bean)
Pregnancy Category: D Cytosar Cytosar-U Tarabine PFS (Rx)
Cytarabine, Liposomal
Cytarabine Liposomal (DepoCyt)
Cytarabine Liposomal
(sye- TAIR-ah-bean)
Pregnancy Category: D DepoCyt (Rx)

Classification: Antineoplastic, antimetabolite

See Also: See also Antineoplastic Agents .

Action/Kinetics: Available as conventional and liposomal products. Converted intracellularly to the active cytarabine-5'-triphosphate, which inhibits DNA polymerase. Is cell-phase specific, acting in the S phase to kill cells undergoing DNA synthesis and also blocking the progression of cells from the G ₁ phase to the S phase. May also decrease the immune response. Conventional cytarabine is not effective PO. Peak plasma levels, after IM or SC: 20-60 min. Liposomal cytarabine is given intrathecally. Peak levels in ventricle and lumbar sac: Within 5 hr. t 1/2, terminal: 100-263 hr. After IV: distribution, 10 min; elimination, 1-3 hr. Metabolized in the liver to uracil arabinoside, which is excreted in the urine. Crosses blood-brain barrier. Eighty percent eliminated in urine in 24 hr.

Uses: Conventional: Induction and maintenance of remission in acute non-lymphocytic leukemia in adults and children, acute myelocytic leukemia in adults and children, acute lymphocytic leukemia in adults and children, chronic myelocytic leukemia, and meningeal leukemia. Liposomal: Intrathecal treatment of lymphomatous meningitis.

Contraindications: Lactation. Use of liposomal product in active meningeal infection or benzyl alcohol-containing products intrathecally.

Special Concerns: Anaphylaxis has occurred, causing acute cardiopulmonary arrest. Use with caution in clients with impaired renal or hepatic function. Safety and efficacy of the liposomal product have not been determined in children (use the conventional product for children). The liposomal product may cause serious toxicity.

Side Effects: Conventional and liposomal cytarabine. CNS: Confusion, somnolence, abnormal gait. GI: N&V;, constipation. Hematologic: Thrombocytopenia, neutropenia, anemia. Miscellaneous: Headache, fever, asthenia, back pain, pain, peripheral edema, urinary incontinence.
Conventional cytarabine.``Cytarabine syndrome'' (6-12 hr following drug administration) manifested by bone pain, fever, myalgia, maculopapular rash, conjunctivitis, chest pain, or malaise. GI: Anorexia, diarrhea, oral and anal inflammation/ulceration, hepatic dysfunction, esophageal ulceration, esophagitis, bowel necrosis, abdominal pain, pancreatitis, jaundice. Respiratory: Pneumonia, shortness of breath. Dermatologic: Rash, cellulitis at injection site, skin ulceration, freckling, alopecia, pruritus, urticaria. Miscellaneous: Thrombophlebitis, bleeding (all sites), sepsis, urinary retention, renal dysfunction, neuritis or neural toxicity, peripheral motor and sensory neuropathies, sore throat, chest pain, pericarditis, conjunctivitis (with rash), dizziness, acute pancreatitis, anaphylaxis allergic edema, headache. Intrathecal administration may result in systemic side effects including N&V;, fever, and rarely neurotoxicity and paraplegia.
Liposomal cytarabine. Arachnoiditis which includes symptoms of neck rigidity, neck pain, meningism, N&V;, headache, fever, back pain, or CSF pleocytosis.

Laboratory Test Alterations: Hyperuricemia. Liposomal product: Transient CSF protein and WBCs.

Overdose Management: Symptoms: CNS toxicity. Treatment: General supportive measures.

Drug Interactions: Absorption of digoxin may be impaired when cytarabine is used with other antineoplastics.

How Supplied: Cytarabine. Injection: 20 mg/mL; Powder for injection: 100 mg, 500 mg, 1 g, 2 g. Cytarabine Liposomal. Injection: 10 mg/mL

Dosage
NOTE: Cytarabine is frequently used in combination with other drugs; thus, dosage varies and must be carefully checked.
Cytarabine, Conventional ?IV Infusion Acute lymphocytic leukemia.
Consult current literature.
Acute nonlymphocytic leukemia (in combination with other drugs).
100 mg/m ²/day by continuous IV infusion (days 1-7) or 100 mg/m ² q 12 hr (days 1-7).
Refractory acute leukemia.
IV: High dose cytarabine: 3 g/m ² given over 2 hr, q 12 hr for 4-12 doses; repeat at 2-3-wk intervals.
?Intrathecal Meningeal leukemia.
Usual: 30 mg/m ² (range: 5-75 mg/m ²) once daily for 4 days to once q 4 days with hydrocortisone, sodium succinate and methotrexate, each at a dose of 15 mg/m ², until CSF findings are normal, followed by one additional dose.
NOTE: The drug should be discontinued if platelet level falls to 50,000/mm ³ or less or polymorphonuclear granulocyte level falls to 1,000/mm ³ or less.
Cytarabine Liposomal ?Intrathecal Lymphomatous meningitis
G Induction: 50 mg q 14 days for 2 doses (weeks 1 and 3). Consolidation therapy: 50 mg q 14 days for 3 doses (weeks 5, 7, and 9). Maintenance: 50 mg q 28 days for 4 doses (weeks 17, 21, 25, and 29). Give either intraventricularly or by lumbar puncture. If drug-related neurotoxicity occurs, reduce the dose to 25 mg followed by 1 additional dose at week13.ive dexamethasone, 4 mg b.i.d., either PO or IV for 5 days starting on the day of liposomal cytarabine.