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Quick facts
- How it is given
- intramuscular, intravenous
- Type
- human prescription drug
- RxNorm ID
- 237788
We do not publish dosing. How much of this medicine to take, how often, and for how long depends on your age, weight, kidney and liver function, other conditions and other medicines. That is a decision for the person who prescribes or dispenses it. Follow the directions on your own pack and ask your pharmacist if anything is unclear.
What it is used to treat
INDICATIONS AND USAGE Leucovorin calcium rescue is indicated after high dose methotrexate therapy in osteosarcoma. Leucovorin calcium is also indicated to diminish the toxicity and counteract the effects of impaired methotrexate elimination and of inadvertent over dosages of folic acid antagonists. Leucovorin calcium is indicated in the treatment of megaloblastic anemias due to folic acid deficiency when oral therapy is not feasible. Leucovorin is also indicated for use in combination with 5-fluorouracil to prolong survival in the palliative treatment of patients with advanced colorectal cancer. Leucovorin should not be mixed in the same infusion as 5-fluorouracil because a precipitate may form.
About this medicine
DESCRIPTION Leucovorin is one of several active, chemically reduced derivatives of folic acid. It is useful as an antidote to drugs which act as folic acid antagonists. Also known as folinic acid, Citrovorum factor, or 5-formyl-5,6,7,8-tetrahydrofolic acid, this compound has the chemical designation of Calcium N -[p-[[[(6 RS )-2-amino-5-formyl-5,6,7,8-tetrahydro-4-hydroxy-6-pteridinyl]methyl]amino]benzoyl]-L-glutamate (1:1). The structural formula of leucovorin calcium is: C 20 H 21 CaN 7 O 7 M.W.=511.51 Leucovorin Calcium for Injection, USP, is a sterile product indicated for intramuscular (IM) or intravenous (IV) administration and is supplied in 100 mg, 200 mg, and 350 mg vials. Each 100 mg vial of Leucovorin Calcium for Injection, USP, when reconstituted with 10 mL of sterile diluent, contains leucovorin (as the calcium salt) 10 mg/mL. Each 200 mg vial of Leucovorin Calcium for Injection, USP, when reconstituted with 20 mL of sterile diluent, contains leucovorin (as the calcium salt) 10 mg/mL. Each 350 mg vial of Leucovorin Calcium for Injection, USP, when reconstituted with 17.5 mL of sterile diluent, contains leucovorin (as the calcium salt) 20 mg/mL. In each dosage form, one milligram of leucovorin calcium, USP contains 0.002 mmol of leucovorin and 0.002 mmol of calcium. These lyophilized products contain no preservative. The inactive ingredient is Sodium Chloride added to adjust tonicity and sodium hydroxide and/or hydrochloric acid for pH adjustment. The pH is between 6.5 and 8.5. Reconstitute with Bacteriostatic Water for Injection, USP, which contains benzyl alcohol (see WARNINGS section), or with Sterile Water for Injection, USP. Structure
Who should not take it
CONTRAINDICATIONS Leucovorin is improper therapy for pernicious anemia and other megaloblastic anemias secondary to the lack of vitamin B 12 . A hematologic remission may occur while neurologic manifestations continue to progress.
Warnings
WARNINGS In the treatment of accidental overdosages of folic acid antagonists, intravenous leucovorin should be administered as promptly as possible. As the time interval between antifolate administration (e.g., methotrexate) and leucovorin rescue increases, leucovorin's effectiveness in counteracting toxicity decreases. In the treatment of accidental overdosages of intrathecally adminstered folic acid antagonists, do not adminster leucovorin intrathecally. LEUCOVORIN MAY BE HARMFUL OR FATAL IF GIVEN INTRATHECALLY. Monitoring of the serum methotrexate concentration is essential in determining the optimal dose and duration of treatment with leucovorin. Delayed methotrexate excretion may be caused by a third space fluid accumulation (i.e., ascites, pleural effusion), renal insufficiency, or inadequate hydration. Under such circumstances, higher doses of leucovorin or prolonged administration may be indicated. Doses higher than those recommended for oral use must be given intravenously. Because of the benzyl alcohol contained in certain diluents used for reconstituting Leucovorin Calcium for Injection, when doses greater than 10 mg/m 2 are administered, Leucovorin Calcium for Injection should be reconstituted with Sterile Water for Injection, USP, and used immediately (see DOSAGE AND ADMINISTRATION section). Because of the calcium content of the leucovorin solution, no more than 160 mg of leucovorin should be injected intravenously per minute (16 mL of a 10 mg/mL, or 8 mL of a 20 mg/mL solution per minute). Leucovorin enhances the toxicity of 5-fluorouracil. When these drugs are administered concurrently in the palliative therapy of advanced colorectal cancer, the dosage of 5-fluorouracil must be lower than usually administered. Although the toxicities observed in patients treated with the combination of leucovorin plus 5-fluorouracil are qualitatively similar to those observed in patients treated with 5-fluorouracil alone, gastrointestinal toxicities (particularly stomatitis and diarrhea) are observed more commonly and may be more severe and of prolonged duration in patients treated with the combination. […]
Reported side effects
ADVERSE REACTIONS Allergic sensitization, including anaphylactoid reactions and urticaria, has been reported following the administration of both oral and parenteral leucovorin. No other adverse reactions have been attributed to the use of leucovorin per se . The following table summarizes significant adverse events occurring in 316 patients treated with the leucovorin/5-fluorouracil combinations compared against 70 patients treated with 5-fluorouracil alone for advanced colorectal carcinoma. These data are taken from the Mayo/NCCTG large multicenter prospective trial evaluating the efficacy and safety of the combination regimen. PERCENTAGE OF PATIENTS TREATED WITH LEUCOVORIN/FLUOROURACIL FOR ADVANCED COLORECTAL CARCINOMA REPORTING ADVERSE EXPERIENCES OR HOSPITALIZED FOR TOXICITY (High LV*) /5-FU (Low LV † ) /5-FU 5-FU Alone (N=155) (N=161) (N=70) Any ‡ Grade 3 +§ Any ‡ Grade 3 +§ Any ‡ Grade 3 +§ (%) (%) (%) (%) (%) (%) Leukopenia 69 14 83 23 93 48 Thrombocytopenia 8 2 8 1 18 3 Infection 8 1 3 1 7 2 Nausea 74 10 80 9 60 6 Vomiting 46 8 44 9 40 7 Diarrhea 66 18 67 14 43 11 Stomatitis 75 27 84 29 59 16 Constipation 3 0 4 0 1 - Lethargy/Malaise/Fatigue 13 3 12 2 6 3 Alopecia 42 5 43 6 37 7 Dermatitis 21 2 25 1 13 - Anorexia 14 1 22 4 14 - Hospitalization for Toxicity 5% 15% 7% * High LV = Leucovorin 200 mg/m 2 † Low LV = Leucovorin 20 mg/m 2 ‡ Any = percentage of patients reporting toxicity of any severity § Grade 3+ = percentage of patients reporting toxicity of Grade 3 or higher
Interactions with other medicines
Drug Interactions Folic acid in large amounts may counteract the antiepileptic effect of phenobarbital, phenytoin and primidone, and increase the frequency of seizures in susceptible pediatric patients. Preliminary animal and human studies have shown that small quantities of systemically administered leucovorin enter the CSF primarily as 5-methyltetrahydrofolate and, in humans, remain 1 to 3 orders of magnitude lower than the usual methotrexate concentrations following intrathecal administration. However, high doses of leucovorin may reduce the efficacy of intrathecally administered methotrexate. Leucovorin may enhance the toxicity of 5-fluorouracil (see WARNINGS section).
If too much is taken
OVERDOSAGE Excessive amounts of leucovorin may nullify the chemotherapeutic effect of folic acid antagonists.
Before you take anything new
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This page is built from the openFDA record of the U.S. Food and Drug Administration's approved labelling for this product, effective 1 June 2022. Label text has been shortened and reformatted for readability; safety wording has not been altered in meaning. FDA labelling describes products approved in the United States — brand names, strengths, formulations and approved uses may differ in your country. Always read the leaflet that comes with your own pack. PocketsInfo is not affiliated with, and is not endorsed by, the FDA. Retrieved 2026-07-30.