leucovorin

Adult Dosing .

Dosage forms:  TAB: 5 mg, 10 mg, 15 mg, 25 mg; INJ: various

leucovorin rescue, high-dose methotrexate

[normal methotrexate elimination]

Dose: 15 mg PO/IM/IV q6h x10 doses; Start: 24h after methotrexate start; Max: 25 mg/dose PO, may give higher doses IM/IV; Info: use this regimen if methotrexate level approximately 10 micromolar at 24h, 1 micromolar at 48h, and <0.2 micromolar at 72h after methotrexate start; incr. to 14 doses with subsequent cycles if abnormal methotrexate elimination or renal impairment; use in combo with hydration and urinary alkalinization

[delayed late methotrexate elimination]

Dose: 15 mg PO/IM/IV q6h; Max: 25 mg/dose PO, may give higher doses IM/IV; Info: continue until methotrexate level <0.05 micromolar; use this regimen if methotrexate level >0.2 micromolar at 72h and >0.05 micromolar at 96h after methotrexate start; use in combo with hydration and urinary alkalinization

[delayed early methotrexate elimination and/or acute renal injury]

Dose: 150 mg IM/IV q3h until methotrexate level <1 micromolar, then 15 mg IM/IV q3h; Info: continue until methotrexate level <0.05 micromolar; use this regimen if methotrexate level >50 micromolar at 24h or >5 micromolar at 48h OR if SCr incr. 100% from baseline at 24h after methotrexate start; use in combo with hydration and urinary alkalinization

leucovorin rescue, impaired methotrexate elimination or overdose

[10 mg/m^2/dose PO/IM/IV q6h]

Start: ASAP after overdose or within 24h if impaired methotrexate elimination; Max: 25 mg/dose PO, may give higher doses IM/IV; Info: continue until methotrexate level <0.01 micromolar; incr. dose to 100 mg/m^2/dose IV q3h if SCr incr. 50% from baseline at 24h OR if methotrexate level >5 micromolar at 24h or >0.9 micromolar at 48h; use in combo with hydration and urinary alkalinization

folate antagonist overdose

[5-15 mg PO qd until hematopoiesis restored]

Info: for folic acid antagonists with less affinity for dihydrofolate reductase than methotrexate, e.g., pyrimethamine, trimethoprim

megaloblastic anemia, folate deficiency-associated

[up to 1 mg IV qd]

colorectal CA

[combo with fluorouracil 370 mg/m^2/day]

Dose: 200 mg/m^2/dose IV x1 on days 1-5 of 28-day cycle; Info: give x2 cycles, then continue 28-day cycles or extend to 35-day cycles; dosing protocols may vary; see pkg insert for 5-FU dose adjustments based on toxicity

[combo with fluorouracil 425 mg/m^2/day]

Dose: 20 mg/m^2/dose IV x1 on days 1-5 of 28-day cycle; Info: give x2 cycles, then continue 28-day cycles or extend to 35-day cycles; dosing protocols may vary; see pkg insert for 5-FU dose adjustments based on toxicity

folate deficiency prevention, pyrimethamine-induced (off-label)

[PCP or toxoplasmosis prophylaxis use]

Dose: 25 mg PO qwk

[toxoplasmosis treatment or maintenance use]

Dose: 10-25 mg PO qd

[cystoisosporiasis treatment or maintenance use]

Dose: 5-25 mg PO qd

renal dosing

[not defined]

renal impairment: not defined

HD/PD: not defined

hepatic dosing

[not defined]

Peds Dosing .

Dosage forms:  TAB: 5 mg, 10 mg, 15 mg, 25 mg; INJ: various

leucovorin rescue, high-dose methotrexate

[normal methotrexate elimination]

Dose: 15 mg PO/IM/IV q6h x10 doses; Start: 24h after methotrexate start; Max: 25 mg/dose PO, may give higher doses IM/IV; Info: use this regimen if methotrexate level approximately 10 micromolar at 24h, 1 micromolar at 48h, and <0.2 micromolar at 72h after methotrexate start; incr. to 14 doses with subsequent cycles if abnormal methotrexate elimination or renal impairment; use in combo with hydration and urinary alkalinization

[delayed late methotrexate elimination]

Dose: 15 mg PO/IM/IV q6h; Max: 25 mg/dose PO, may give higher doses IM/IV; Info: continue until methotrexate level <0.05 micromolar; use this regimen if methotrexate level >0.2 micromolar at 72h and >0.05 micromolar at 96h after methotrexate start; use in combo with hydration and urinary alkalinization

[delayed early methotrexate elimination and/or acute renal injury]

Dose: 150 mg IM/IV q3h until methotrexate level <1 micromolar, then 15 mg IM/IV q3h; Info: continue until methotrexate level <0.05 micromolar; use this regimen if methotrexate level >50 micromolar at 24h or >5 micromolar at 48h OR if SCr incr. 100% from baseline at 24h after methotrexate start; use in combo with hydration and urinary alkalinization

leucovorin rescue, impaired methotrexate elimination or overdose

[10 mg/m^2/dose PO/IM/IV q6h]

Start: ASAP after overdose or within 24h if impaired methotrexate elimination; Max: 25 mg/dose PO, may give higher doses IM/IV; Info: continue until methotrexate level <0.01 micromolar; incr. dose to 100 mg/m^2/dose IV q3h if SCr incr. 50% from baseline at 24h OR if methotrexate level >5 micromolar at 24h or >0.9 micromolar at 48h; use in combo with hydration and urinary alkalinization

folate antagonist overdose

[5-15 mg PO qd until hematopoiesis restored]

Info: for folic acid antagonists with less affinity for dihydrofolate reductase than methotrexate, e.g., pyrimethamine, trimethoprim

megaloblastic anemia, folate deficiency-associated

[up to 1 mg IV qd]

folate deficiency prevention, pyrimethamine-induced (off-label)

[toxoplasmosis prophylaxis or suppression use]

Dose: 5 mg PO q3 days

[congenital toxoplasmosis treatment use]

Dose: 10 mg PO/IM with each pyrimethamine dose

[acquired toxoplasmosis treatment use]

Dose: 10-25 mg PO qd

[cystoisosporiasis use]

Dose: 5-15 mg PO qd

renal dosing

[not defined]

renal impairment: not defined

HD/PD: not defined

hepatic dosing

[not defined]