Adult Dosing
Impaired methotrexate elimination
- 15 mg PO q6 hrs, continue till methotrexate level is 0.01 micromolar
- Doses >25 mg to be given IV/IM
- Increase dose to 150 mg IM/IV q3 hrs if serum Cr is >50% at 24 hrs or methotrexate level at 48 hrs is >0.9 micromolar
- Initiate rescue within 24 hrs of methotrexate infusion and concomitantly administer NaHCO3 to maintain urine pH
7
Overdosage of folic acid antagonists
- 5-15 mg PO qd, continue till hematopoesis is restored
Pediatric Dosing
Impaired methotrexate elimination
- 15 mg PO q6 hrs, continue till methotrexate level is 0.01 micromolar
- Doses >25 mg to be given IV/IM
- Increase dose to 150 mg IM/IV q3 hrs if serum Cr is >50% at 24 hrs or methotrexate level at 48 hrs is >0.9 micromolar
- Initiate rescue within 24 hrs of methotrexate infusion and concomitantly administer NaHCO3 to maintain urine pH 7
Overdosage of folic acid antagonists
- 5-15 mg PO qd, continue till hematopoesis is restored
[Outline]
- Use of leucovorin for treatment of pernicious anemia and other megaloblastic anemias secondary to the lack of vitamin B12 is contraindicated due to risk of hematologic remission
- In case of accidental overdosage of folic acid antagonists, prompt administration of leucovorin is advised. Any delay would decrease its effectiveness in counteracting hematologic toxicity
- Monitor serum methotrexate concentration to determine the optimal dose and treatment duration of leucovorin
- Fluid accumulation, renal insufficiency or inadequate hydration may delay excretion of methotrexate. Higher doses of leucovorin or extended administration is advised in such cases
- Fatal cases of enterocolitis, diarrhea, and dehydration have been reported in elderly patients due to enhancement of fluorouracil toxicity by leucovorin
- Concurrent use of trimethoprim-sulfamethoxazole for treatment of pneumonia in HIV patients may result in increased mortality and failure of treatment
- Oral treatment with leucovorin should be avoided if patient is vomiting, as drug absorption may not be complete. Use IV/IM route instead
Cautions: Use cautiously in
- Renal insufficiency
- Fluid accumulation
- Dehydration
- Elderly
Pregnancy Category:C
Breastfeeding: Safety unknown. As many drugs are excreted in human milk, manufacturer advises caution while administering to nursing women.
US Trade Name(s)
US Availability
leucovorin (generic)
Canadian Trade Name(s)
Canadian Availability
leucovorin (generic)
UK Trade Name(s)
UK Availability
calcium folinate (generic)
Refolinon
Australian Trade Name(s)
Australian Availability
leucovorin (generic)
[Outline]