Nurses Compass
Drug Guide
Cytarabine
Classification
Therapeutic: Antineoplastic agent, Antimetabolite
Pharmacological: Pyrimidine nucleoside analog
FDA Approved Indications
- Acute myeloid leukemia (AML)
- Lymphoma (e.g., non-Hodgkin lymphoma)
- Central nervous system (CNS) prophylaxis and treatment in leukemia
Mechanism of Action
Cytarabine inhibits DNA synthesis by being incorporated into DNA during the S-phase of the cell cycle, leading to chain termination and cell death.
Dosage and Administration
Adult: Prescribed based on condition; for AML, typical IV doses range from 100-200 mg/m^2 daily for several days; intrathecal administration is used for CNS prophylaxis or treatment.
Pediatric: Dosing varies with age and weight; specific protocols must be followed.
Geriatric: Use cautiously; individualized dosing recommended due to potential toxicity.
Renal Impairment: Adjust dose accordingly; renal function affects clearance.
Hepatic Impairment: No specific adjustment; monitor closely.
Pharmacokinetics
Absorption: Poor oral bioavailability; administered intravenously, intrathecally, or via continuous infusion.
Distribution: Widely distributed, including CNS with intrathecal administration.
Metabolism: Limited hepatic metabolism; predominantly metabolized in tissues.
Excretion: Renally excreted; dose adjustment needed in renal impairment.
Half Life: Approximately 8-20 minutes for plasma; metabolites have longer half-lives.
Contraindications
- Hypersensitivity to cytarabine or related compounds.
Precautions
- Use with caution in renal or hepatic impairment, in patients with active infections, and in pregnant or breastfeeding women. Neurotoxicity risk with high doses. Potential for myelosuppression.
Adverse Reactions - Common
- Myelosuppression (neutropenia, anemia, thrombocytopenia) (Very common)
- Nausea and vomiting (Common)
- Stomatitis (Common)
- Conjunctivitis (Less common)
Adverse Reactions - Serious
- Neurotoxicity (cerebellar toxicity, neuropsychological effects) (Rare at standard doses; increased risk with high doses)
- Infections due to immunosuppression (Common)
- Pulmonary toxicity (interstitial pneumonitis) (Rare)
- Secondary malignancies (e.g., myelodysplastic syndromes) (Very rare)
Drug-Drug Interactions
- May enhance myelosuppression when combined with other myelosuppressive agents (e.g., cyclophosphamide, carboplatin)
Drug-Food Interactions
- No significant interactions reported.
Drug-Herb Interactions
- Limited data; caution advised with herbs affecting liver enzymes or immune system.
Nursing Implications
Assessment: Monitor blood counts regularly; assess for signs of neurotoxicity, pulmonary toxicity, and infections.
Diagnoses:
- Risk for infection related to immunosuppression.
- Risk for bleeding related to thrombocytopenia.
Implementation: Administer as prescribed, monitor labs closely, educate patient about signs of adverse effects.
Evaluation: Efficacy assessed by disease response; toxicity monitored through labs and clinical assessment.
Patient/Family Teaching
- Report symptoms of infection, neurotoxicity, or pulmonary issues immediately.
- Avoid pregnancy; use effective contraception.
- Maintain good hygiene and infection prevention measures.
Special Considerations
Black Box Warnings:
- Neurotoxicity, especially with high doses or intrathecal administration.
- Potential for severe myelosuppression leading to infections and bleeding.
Genetic Factors: Limited data on genetic influences.
Lab Test Interference: May cause cytopenias that affect lab results.
Overdose Management
Signs/Symptoms: Severe myelosuppression, neurotoxicity, seizures, coma.
Treatment: Supportive care; no specific antidote. Hematopoietic growth factors may be considered; hemodialysis not effective.
Storage and Handling
Storage: Store vials at 2-8°C, protected from light.
Stability: Stable until expiration date on package.