Trade Names:Wellcovorin- Tablets 5 mg- Tablets 25 mgLederle Leucovorin Calcium (Canada)
Acts as antidote to drugs that antagonize folic acid, such as methotrexate.
Following a 25-mg dose C max is 393 ng/mL (160 to 550 ng/mL), T max is 2.3 h, and apparent bioavailability is 97% for 25-mg dose.
Metabolites are L-leucovorin, d-leucovorin, and 5-methyl-THF.
Terminal t ½ is 5.7 h.
Treatment to diminish toxicity and counteract effect of overdosage of folic acid antagonists.Parenteral
Treatment of megaloblastic anemia caused by folic acid deficiency when oral therapy is not feasible.
Pernicious anemia and other megaloblastic anemias secondary to vitamin B 12 deficiency.
IV Either 200 mg/m 2 followed by 5-fluorouracil (5-FU) 370 mg/m 2 or 20 mg/m 2 followed by 5-FU 425 mg/m 2 every day for 5 days.Leucovorin RescueAdults
PO / IV / IM 10 mg/m 2 every 6 h for 10 doses.Megaloblastic Anemia Caused by Folic Acid DeficiencyAdults
IV / IM 1 mg/day.
Store at room temperature and protect from light.
May decrease anticonvulsant activity.Fluorouracil
Enhances toxicity of fluorouracil.Methotrexate
May decrease efficacy of intrathecal methotrexate.
None well documented.
Hypersensitivity, including anaphylaxis and urticaria. No other adverse reactions have been attributed to leucovorin alone.
Ensure that daily methotrexate levels are obtained when leucovorin is used for high-dose methotrexate rescue.
Category C .
Present in 1 mL amp and some diluents. Benzyl alcohol has been associated with fatal “gasping syndrome” in premature infants.
Leucovorin enhances toxicity of 5-FU; decrease dosage. Administer only under supervision of health care provider experienced in use of antimetabolite cancer chemotherapy.
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