Cytarabine Liposomal

Pronunciation: SITE-ah-rah-been
Class: Pyrimidine analog

Trade Names

DepoCyt
- Suspension equivalent to 10 mg/mL cytarabine

Pharmacology

Cytarabine exhibits cell-phase specificity, primarily killing cells undergoing DNA synthesis (S-phase) and under certain conditions, blocking the progression of cells from the G ₁ phase to the S-phase.

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Pharmacokinetics

Absorption

T _max is within 5 h for free cytarabine in both the ventricle and the lumbar sac.

Metabolism

Intracellularly converted to cytarabine-5′-triphosphate (ara-CTP), which is the active metabolite. Metabolism to ara-U (inactive) is primary route of elimination.

Elimination

ara-U is excreted in the urine. Biphasic elimination; terminal t _½ is 100 to 263 h (12.5 to 75 mg).

Indications and Usage

Adult

Lymphomatous meningitis.

Contraindications

Active meningeal infection hypersensitivity to cytarabine or any other ingredient in the formulation.

Dosage and Administration

Liposomal Cytarabine Dose

The dose of liposomal cytarabine is different from the dose of conventional cytarabine.

Induction Therapy Adults

Intrathecally 50 mg every 14 days for 2 doses, during weeks 1 and 3.

Consolidation Therapy Adults

Intrathecally 50 mg every 14 days for 3 doses, during weeks 5, 7, and 9. Then, give an additional 50 mg dose during week 13.

Maintenance Regimen Adults

Intrathecally 50 mg every 28 days for 4 doses, during weeks 17, 21, 25, and 29.

Dosage Adjustment for Neurologic Toxicity Adults

Intrathecally If neurologic toxicity occurs, reduce the dose to 25 mg. Discontinue if toxicity persists.

Pretreatment Regimen Adults

Intrathecally To reduce the incidence of chemical arachnoiditis, treat all patients with 4 mg dexamethasone orally or IV twice daily for 5 days starting the day of liposomal cytarabine administration. Inject via an intraventricular reservoir or directly into the lumbar sac. The patient should lie flat for at least 1 h after the injection. Do not use in-line filters.

General Advice

• Warm the vial to room temperature. Gently swirl or invert the vial to suspend the particles.
• Do not dilute.
• Liposomal cytarabine is preservative-free. Use the suspension within 4 h after removing it from the vial.
• Administer by intrathecal injection over 1 to 5 min.

Storage/Stability

Refrigerate unopened vials; do not freeze. Avoid shaking vials vigorously. Unopened vials are stable at room temperature for up to 72 h.

Drug Interactions

Antineoplastics

Coadministration may increase the risk of neurotoxicity.

Gentamicin

Gentamicin effectiveness against Klebsiella pneumoniae strains may be decreased.

Laboratory Test Interactions

Because liposomal cytarabine particles are similar in size and appearance to white blood cells, take care in interpreting CSF examinations following liposomal cytarabine administration.

Adverse Reactions

CNS

Headache; asthenia; confusion; somnolence; Transient elevations in CSF protein and WBC; encephalopathy; gait disturbance; neurotoxicity; meningismus; paresthesia.

GI

Nausea; vomiting; constipation.

Hematologic

Neutropenia; thrombocytopenia.

Musculoskeletal

Myelopathy; back pain; pain.

Miscellaneous

Chemical arachnoiditis syndrome; nausea; vomiting; headache; fever; neck rigidity; neck pain; meningismus; back pain; CSF pleocytosis.

Precautions

Monitor Bone marrow examinations During induction therapy, perform leukocyte and platelet counts daily. Perform bone marrow examinations frequently after blasts have disappeared from the peripheral blood. Drug-induced marrow depression Suspend or modify therapy when drug-induced marrow depression results in a platelet count less than 50,000/mm 3 or a polymorphonuclear granulocyte count less than 1,000/mm 3 .

Pregnancy

Category D .

Children

Safety and efficacy have not been established.

Hypersensitivity

Cases of anaphylaxis have occurred resulting in acute cardiopulmonary arrest which required resuscitation. This occurred immediately after IV administration.

Renal Function

Patients with renal function impairment may have a higher likelihood of CNS toxicity after high-dose cytarabine. Use the drug with caution and possibly at reduced doses in patients with poor kidney function.

Hepatic Function

Patients with hepatic function impairment may have a higher likelihood of CNS toxicity after high-dose cytarabine. Use the drug with caution and possibly at reduced doses in patients with poor hepatic function.

Chemical arachnoiditis

A syndrome manifested primarily by nausea, vomiting, headache, and fever has been a common adverse reaction in all studies. If left untreated, chemical arachnoiditis may be fatal. The incidence and severity of chemical arachnoiditis can be reduced by coadministration of dexamethasone.

CSF examination interpretation

Liposomal cytarabine particles and white blood cells are similar in appearance and size. Use caution when interpreting CSF examinations after administration of liposomal cytarabine.

Extravasation risk

Liposomal cytarabine is an irritant and can cause local irritation or phlebitis. Refer to your institution specific protocol.

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.

Intrathecal use

If used intrathecally, do not use a diluent with benzyl alcohol.

Myelosuppression/Hematologic

Anemia, leukopenia, thrombocytopenia, megaloblastosis, and reduced reticulocytes can be expected. The severity of these reactions is dose- and schedule-dependent.

Neuropathies

Peripheral motor and sensory neuropathies have occurred.

Neurotoxicity

Enhanced neurotoxicity has been associated with concurrent use of intrathecal cytarabine and other cytotoxic agents administered intrathecally. Monitor neurologic function at baseline and periodically throughout treatment.

Patient Information

• Inform patients about the expected adverse reactions of headache, nausea, vomiting and fever, and about the early signs and symptoms of neurotoxicity.
• Emphasize the importance of dexamethasone coadministration at the initiation of each cycle of liposomal cytarabine treatment. Instruct patients to seek medical attention if signs or symptoms of neurotoxicity develop, or if oral dexamethasone is not well tolerated.

Copyright © 2009 Wolters Kluwer Health.