Leucovorin Calcium
Also known as: Folinic acid, Citrovorum factor
> **Important**: If this medication is being used to treat methotrexate toxicity, it should only be administered in an inpatient hospital setting under strict veterinary supervision. * **Administration**: Oral leucovorin may be given with or without meals. * **Strict Adherence**: It is critical to follow the exact dosage schedule prescribed by your veterinarian. Missing doses can compromise the treatment or prevention of severe blood cell abnormalities (hematologic toxicity). * **Missed Doses**: If you miss a dose, contact your veterinarian for instructions. Do not double up on doses without professional guidance.
Dosage must be set by your veterinarian for your specific pet. Never give human medication or another pet’s prescription without veterinary guidance.
What it is used for
- Folate deficiency associated with pyrimethamine use
- Bone marrow suppression associated with pyrimethamine or trimethoprim/sulfa
- To prevent bone marrow toxicity associated with pyrimethamine
- Methotrexate overdose
- Macrocytic anemia and neutropenia associated with pyrimethamine and/or trimethoprim (especially in pregnant mares)
- Folate deficiency associated with pyrimethamine use
- Methotrexate overdose
How it is given
Possible side effects
- Gastrointestinal effects (noted in humans with oral administration)
- Seizures (very rare, noted in humans)
- Hypersensitivity reactions (very rare, noted in humans)
Cautions & contraindications
- Known intolerance or hypersensitivity to leucovorin
- Use with extreme caution in patients receiving systemic fluorouracil. Because of its calcium content, large intravenous doses should be given slowly and not bolused. In humans, folinic acid therapy may mask the signs associated with cobalamin (B-12) deficiency in megaloblastic anemias. When reconstituting powder with bacteriostatic water (which contains benzyl alcohol), avoid use in neonates or very small animals.
Drug interactions
- Barbiturates, Primidone, Phenytoin: Large doses of leucovorin may reduce the antiseizure efficacy of these agents.
- Fluorouracil (5-FU): Leucovorin may increase both the antineoplastic efficacy and toxicity of 5-FU.
- Trimethoprim, Ormetoprim, Pyrimethamine: Leucovorin may reduce their efficacy somewhat; however, protozoa cannot utilize leucovorin, preserving the antimicrobial effect against them.
Frequently asked questions
What is Leucovorin Calcium used for in pets?
> **Important**: If this medication is being used to treat methotrexate toxicity, it should only be administered in an inpatient hospital setting under strict veterinary supervision. * **Administration**: Oral leucovorin may be given with or without meals. * **Strict Adherence**: It is critical to follow the exact dosage schedule prescribed by your veterinarian. Missing doses can compromise the treatment or prevention of severe blood cell abnormalities (hematologic toxicity). * **Missed Doses**: If you miss a dose, contact your veterinarian for instructions. Do not double up on doses without professional guidance.
Is Leucovorin Calcium safe for my pet?
Dosage must be set by your veterinarian for your specific pet. Never give human medication or another pet’s prescription without veterinary guidance.
This article is for general education and is not a substitute for professional veterinary advice. If your pet is unwell, please consult a veterinarian.
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