Generic Name

Leucovorin Calcium

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Classification

FDA Approved Indications

• Rescue from toxicity of high-dose methotrexate therapy
• Treatment of megaloblastic anemia due to folic acid deficiency
• Adjunct in chemotherapy regimens for colorectal cancer

Mechanism of Action

Leucovorin is converted into tetrahydrofolate, which is used in nucleotide synthesis and repair, rescuing normal cells from the toxic effects of methotrexate and supporting DNA synthesis.

Dosage and Administration

Adult: Dosing varies based on indication; for methotrexate rescue, typically 15 mg orally every 6 hours for 8 doses starting 24 hours after methotrexate infusion.

Pediatric: Dose based on body surface area or weight; specific regimens depend on indication.

Geriatric: Adjustments may be necessary based on renal function and overall condition.

Renal Impairment: Adjust dosage based on degree of impairment; close monitoring is required.

Hepatic Impairment: No specific adjustments recommended; use with caution.

Pharmacokinetics

Absorption: Orally absorbed with bioavailability of approximately 20-30%.

Distribution: Widely distributed in body tissues; crosses the blood-brain barrier.

Metabolism: Metabolized in the liver to active forms.

Excretion: Excreted primarily in urine.

Half Life: Approximately 6-24 hours depending on dose and renal function.

Contraindications

• Hypersensitivity to leucovorin or folates

Precautions

• Use with caution in patients with pulmonary disease, epilepsy, or seizures.
• Potential for interference with folic acid antagonists' activity.

Adverse Reactions - Common

• Flush (Rare)
• Mild gastrointestinal upset (Common)

Adverse Reactions - Serious

• Hypersensitivity reactions including rash, anaphylaxis (Rare)
• Elevated liver enzymes (Uncommon)

Drug-Drug Interactions

• Methotrexate (may antagonize its effect at high doses)

Drug-Food Interactions

N/A

Drug-Herb Interactions

N/A

Nursing Implications

Patient/Family Teaching

• Inform about the purpose of leucovorin during chemotherapy.
• Report any signs of allergic reactions such as rash, difficulty breathing.
• Use as prescribed; do not take more or less without consulting a healthcare provider.

Special Considerations

Black Box Warnings: N/A

Genetic Factors: No specific genetic considerations identified.

Lab Test Interference: May interfere with certain laboratory tests; communicate to lab personnel if necessary.

Overdose Management

Signs/Symptoms: Rare, but overdose may result in decreased serum folate levels causing symptoms similar to deficiency.

Treatment: Supportive care; discontinue leucovorin; monitor for adverse effects.

Storage and Handling

Storage: Store at 20-25°C (68-77°F); protect from light.

Stability: Stable for the duration of the labeled shelf life when stored properly.