๋ฅ์ฝ๋ณด๋ฆฐ ์นผ์
๋ฅ์ฝ๋ณด๋ฆฐ ์นผ์(ํด๋ฆฌ๋์ฐ)์ ํ์ํ ์ฝ์ฐ ์ ๋์ฒด๋ก, ์์ํ์์๋ ์ฃผ๋ก **๊ตฌ์กฐ ์๋ฒ์ ** ๋๋ **ํด๋ ์ **๋ก ์ฌ์ฉ๋ฉ๋๋ค. * **์ฃผ์ ์ ์์ฆ**: ๋ํ๋๋ก์ฝ์ฐ ํ์ํจ์ ์ต์ ์ (์: ํผ๋ฆฌ๋ฉํ๋ฏผ, ํธ๋ฆฌ๋ฉํ ํ๋ฆผ, ์ค๋ฅด๋ฉํ ํ๋ฆผ ๋ฑ)์ ๊ด๋ จ๋ ํ์ก ๋ ์ฑ(๊ณจ์ ์ต์ , ๊ฑฐ๋์ ์๊ตฌ์ฑ ๋นํ, ํธ์ค๊ตฌ ๊ฐ์์ฆ ๋ฑ)์ ์ญ์ ์ํค๊ฑฐ๋ ์๋ฐฉํ๋ ๋ฐ ์ฌ์ฉ๋ฉ๋๋ค. * **๋ฉํ ํธ๋ ์ธ์ดํธ ๊ตฌ์กฐ**: ์ธ์์์๋ ๊ณ ์ฉ๋ ๋ฉํ ํธ๋ ์ธ์ดํธ ํํ์๋ฒ์ ๊ตฌ์กฐ ์๋ฒ์ ๋ก ์ผ์์ ์ผ๋ก ์ฌ์ฉ๋์ง๋ง, ์์ํ์์๋ ์ฐ๋ฐ์ ์ธ ๋ฉํ ํธ๋ ์ธ์ดํธ ๊ณผ๋ค ๋ณต์ฉ์ ๊ฒฝ์ฐ๋ฅผ ์ ์ธํ๊ณ ๋ ์ด ๋ชฉ์ ์ผ๋ก ๊ฑฐ์ ์ฌ์ฉ๋์ง ์์ต๋๋ค. * **์์์ ํน์ง**: ์ผ๋ฐ ์ฝ์ฐ๊ณผ ๋ฌ๋ฆฌ ๋ฅ์ฝ๋ณด๋ฆฐ์ ์๋ฌผํ์ ํ์ฑ์ ๋ํ๋ด๊ธฐ ์ํด ๋ํ๋๋ก์ฝ์ฐ ํ์ํจ์์ ๋ณํ์ **ํ์๋ก ํ์ง ์์ต๋๋ค**. ์ด๋ฅผ ํตํด ์ฝ์ฐ ๊ธธํญ์ ์ ์ํ ํจ์ ์ฐจ๋จ์ ์ฐํํ์ฌ ์ธํฌ ๊ธฐ๋ฅ์ ํ์ํ ์ฝ์ฐ์ ์ง์ ๊ณต๊ธํ ์ ์์ต๋๋ค.
์์ฉ ๊ธฐ์ : Leucovorin is a reduced form of folic acid that acts as a direct coenzyme in cellular metabolism. * **Bypassing DHFR**: It does not require conversion by **dihydrofolate reductase (DHFR)** to become biologically active. * **Active Metabolite**: It is converted in the body to active reduced forms, predominantly **5-methyltetrahydrofolate (5-methyl THF)**. * **DNA Synthesis**: These reduced folates act as coenzymes in the synthesis of **purine and pyrimidine nucleotides** โ essential for **DNA synthesis** and the maintenance of normal **erythropoiesis** (red blood cell production). * **Enzyme Inhibition**: Leucovorin inhibits **thymidylate synthase** by stabilizing the binding of fluorodeoxyuridylic acid to the enzyme. This mechanism potentiates both the antineoplastic activity and the toxicity of **fluorouracil (5-FU)**.
๋๋ฌผ ์ข ๋ณ ์ฉ๋
- Folate deficiency associated with pyrimethamine use ยท 5-15 mg (total dose) PO or parenterally once daily ยท PO/Parenteral ยท q24h
- Bone marrow suppression associated with pyrimethamine or trimethoprim/sulfa ยท 5 mg once daily ยท Not specified ยท q24h
- To prevent bone marrow toxicity associated with pyrimethamine ยท 1 mg/kg once daily ยท Not specified ยท q24h
- Methotrexate overdose ยท 25-200 mg/m2 parenterally every 6 hours until methotrexate levels are less than 1 X 10 -8 M ยท Parenteral ยท q6h ยท Until methotrexate levels are < 1 X 10^-8 M ยท Most effective if given within 48 hours of overdose.
- Macrocytic anemia and neutropenia associated with pyrimethamine and/or trimethoprim (especially in pregnant mares) ยท 0.1-0.3 mg/kg PO once daily ยท PO ยท q24h ยท A more practical approach would be to ensure that the horse receives green hay or pasture (high tetrahydrofolate levels in green roughage).
- Folate deficiency associated with pyrimethamine use ยท 5-15 mg (total dose) PO or parenterally once daily ยท PO/Parenteral ยท q24h
- Methotrexate overdose ยท 25-200 mg/m2 parenterally every 6 hours until methotrexate levels are less than 1 X 10 -8 M ยท Parenteral ยท q6h ยท Until methotrexate levels are < 1 X 10^-8 M ยท Most effective if given within 48 hours of overdose. Dose is dependent on serum methotrexate concentration.
์ฉ๋์ ๋ฉดํ ์์ ์ ๋ฌธ๊ฐ๋ฅผ ์ํ ์์ ์ฐธ๊ณ ์๋ฃ์ ๋๋ค. ํญ์ ์ต์ ๋ผ๋ฒจ๊ณผ ๊ฐ๋ณ ํ์์ ๋ํด ํ์ธํ์ญ์์ค.
ํฌ์ฌ ๊ฒฝ๋ก
๊ธ๊ธฐ
- Known intolerance or hypersensitivity to leucovorin
์ด์๋ฐ์
- Gastrointestinal effects (noted in humans with oral administration)
- Seizures (very rare, noted in humans)
- Hypersensitivity reactions (very rare, noted in humans)
์ฝ๋ฌผ ์ํธ์์ฉ
- Barbiturates, Primidone, Phenytoin ยท Large doses of leucovorin may reduce the antiseizure efficacy of these agents.
- Fluorouracil (5-FU) ยท Leucovorin may increase both the antineoplastic efficacy and toxicity of 5-FU.
- Trimethoprim, Ormetoprim, Pyrimethamine ยท Leucovorin may reduce their efficacy somewhat; however, protozoa cannot utilize leucovorin, preserving the antimicrobial effect against them.
๋ชจ๋ํฐ๋ง
- Complete Blood Count (CBC)
- Methotrexate serum levels (if used for methotrexate overdoses; may require contacting a local human hospital)
๊ณผ์ฉ๋
Except in situations where drug interactions are possible (e.g., with fluorouracil or antiseizure medications), an inadvertent overdose is unlikely to be of clinical concern.
VetSheet ์ฝ๋ฌผ ๋ ํผ๋ฐ์ค๋ ๋ฉดํ ์์ ์ ๋ฌธ๊ฐ๋ฅผ ์ํ ์์ ์์ฌ๊ฒฐ์ ๋ณด์กฐ ๋๊ตฌ์ด๋ฉฐ, ์ ๋ฌธ์ ํ๋จ์ด๋ ์ ์กฐ์ฌ์ ์ต์ ๋ผ๋ฒจ์ ๋์ ํ์ง ์์ต๋๋ค.