Drug Guide
Levoleucovorin Calcium
Classification
Therapeutic: Antidote / Adjuvant in chemotherapy
Pharmacological: Folic acid derivative
FDA Approved Indications
- Levoleucovorin is used to rescue normal cells from the toxic effects of methotrexate in high-dose methotrexate therapy.
- It is also used as an adjunct to chemotherapy with fluorouracil for metastatic colorectal cancer.
Mechanism of Action
Levoleucovorin provides reduced folate (leucovorin) which replenishes folate pools in cells, counteracting the effects of folic acid antagonists like methotrexate and potentiating the action of fluorouracil.
Dosage and Administration
Adult: Dose varies depending on indication; for methotrexate rescue, 15 mg intramuscularly or intravenously every 6 hours for 8 doses starting 24 hours after methotrexate.
Pediatric: Dosing based on body surface area or weight; specific dosing recommendations should be followed according to clinical protocols.
Geriatric: Adjustments may be necessary based on renal function; consult specific guidelines.
Renal Impairment: Dose adjustments are necessary; monitor renal function closely.
Hepatic Impairment: No specific adjustments established; use caution and monitor hepatic function.
Pharmacokinetics
Absorption: Rapid intravenous absorption.
Distribution: Widely distributed in body tissues, crosses the blood-brain barrier.
Metabolism: Not extensively metabolized.
Excretion: Primarily excreted unchanged in urine.
Half Life: Approximately 6 hours.
Contraindications
- Hypersensitivity to leucovorin or folinic acid.
Precautions
- Use with caution in patients with folate deficiency, megaloblastic anemia, or conditions where folate could exacerbate underlying disease.
- Renal impairment requires dose adjustments.
Adverse Reactions - Common
- Allergic reactions (rash, itching, swelling) (Uncommon)
- Gastrointestinal upset (Common)
Adverse Reactions - Serious
- Anaphylaxis, severe allergic reactions (Rare)
- Neurotoxicity when used with high doses of methotrexate (Rare)
Drug-Drug Interactions
- Methotrexate (antagonizes effects; requires dose adjustments)
- Fluorouracil (potentiates toxicity)
Drug-Food Interactions
N/ADrug-Herb Interactions
N/ANursing Implications
Assessment: Monitor renal function, complete blood count, and signs of allergic reactions.
Diagnoses:
- Risk for allergic reaction
- Imbalance nutrition: less than body requirements due to gastrointestinal upset
Implementation: Administer as prescribed, typically IV or IM, and monitor for adverse reactions.
Evaluation: Assess patient’s response, observe for reduction in methotrexate toxicity, and monitor for adverse effects.
Patient/Family Teaching
- Inform about potential allergic reactions and importance of reporting symptoms.
- Advise on adherence to dosing schedule and regular laboratory testing.
Special Considerations
Black Box Warnings:
- None specific to levoleucovorin, but caution with high-dose methotrexate therapy.
Genetic Factors: No significant genetic considerations.
Lab Test Interference: May interfere with folate and vitamin B12 testing results.
Overdose Management
Signs/Symptoms: Symptoms of overdose are unlikely; overdose may cause hyperfolatemia or confusion.
Treatment: Supportive care; no specific antidote. Hemodialysis may be considered in cases of renal failure.
Storage and Handling
Storage: Store at 20°C to 25°C (68°F to 77°F). Protect from light.
Stability: Stable when stored properly; check manufacturer’s expiration date.