- To counteract ("rescue") the continuing marrow toxicity of large doses of folic acid antagonists (especially methotrexate >300 mg/m2)
- Treatment of megaloblastic anemia due to folate deficiency, when oral therapy is not feasible
- Available as a 10 mg/mL solution
- Refrigerate vials. Stable 7 days at room temperature
- Stable 24 hours at room temperature when diluted in compatible solutions
- Stable 8 hours in syringe (Novopharm product)
- Stable 48 hours at room temp and 7 days in fridge (Hospira product)
- Protect from light
- Solutions Compatible: dextrose solutions up to D10W, 0.9% NaCl, and combinations
- Additive/Above Cassette Compatible: no information
- Y-site Compatible: filgrastim, fluconazole, 5-fluorouracil, heparin, metoclopramide, non-acetate containing TPN (amino acids/dextrose)
- Incompatible: amphotericin B, sodium bicarbonate, droperidol
(For approved routes of administration by nursing personnel, refer to Policy for the Administration of Intravenous Medications.)
SC | NO |
IM | YES |
IV Direct | NO |
IV Intermittent Infusion |
YES Infusion time: 15-60 minutes |
IV Continuous Infusion | NO |
(For neonatal dosages, refer to Neonatal IV Drug Manual.)
"Rescue" Therapy after Methotrexate Administration:
- Dose and schedule vary according to protocol and/or methotrexate serum level
- Usual dose 10-15 mg/m2 q6h, beginning 24-48 hours after the start of methotrexate until serum methotrexate level falls below 1 x 10-7 M (0.1 microMolar).
Bleyer Nomogram for Delayed Elimination of Methotrexate:
48 Hour Methotrexate Level |
Leucovorin Dose |
<1 microMolar |
10 mg/m2 q6h |
<8 microMolar |
100 mg/m2 q6h |
>8 microMolar |
1,000 mg/m2 q6h |
Megaloblastic Anemia
- 1 mg IM daily (doses greater than 1 mg have no greater efficacy)
- Allergic reactions (rare)
- Not to be used for the treatment of pernicious anemia or other megaloblastic anemias secondary to a Vitamin B12 deficiency (hematologic effects of Vitamin B12 deficiency may be masked, but neurologic abnormalities will not be prevented)
- If serum creatinine is increased by more than 50% above baseline 24 hours after methotrexate administration, increase leucovorin dose to 100 mg/m2 q3h until serum methotrexate level falls below 5 x 10-8 Molar (0.05 microMolar) and obtain a nuclear GFR
- High doses of methotrexate (>5 g/m2) are rescued at 24-36 hours
- Intermediate doses of methotrexate (< 5 g/m2) are usually rescued at 42-48 hours
- High doses of leucovorin may reduce the efficacy of intrathecally administered methotrexate