엽산

수용성 B군 비타민 (비타민 B9)

**엽산**(비타민 B9)은 **핵단백질 합성** 및 **정상적인 적혈구 생성**에 필수적인 중요한 수용성 비타민입니다. 수의학에서는 주로 위장관 질환에 속발하는 엽산 결핍증을 치료하는 데 사용됩니다. **임상적 특징 및 진단적 유용성:** - **흡수 부위:** 엽산은 **근위 소장**에서 독점적으로 흡수되는 반면, 코발라민(비타민 B12)은 원위 소장에서 흡수됩니다. - **진단 지표:** 혈청 엽산 및 코발라민 측정은 장 질환의 위치를 파악하는 데 도움이 됩니다. 엽산 수치 저하는 근위 소장 질환을 시사합니다. - **세균 과증식:** 외분비 췌장 기능 부전(EPI) 또는 소장 세균 과증식(SIBO)이 있는 개는 장내 세균이 엽산을 합성하기 때문에 혈청 엽산 수치가 *증가*하는 경우가 많습니다. - **항엽산제 구조 요법:** 디히드로엽산 환원효소 억제제(예: 트리메토프림, 피리메타민)의 장기 투여로 인한 결핍을 예방하거나 치료하는 데에도 사용됩니다.

작용 기전: Folic acid is a precursor that must be enzymatically reduced to become biologically active. **Mechanism Pathway:** **Folic Acid** → reduced by **dihydrofolate reductase (DHFR)** → **Tetrahydrofolate (THF / 5-methyltetrahydrofolate)**. - **THF** acts as a crucial coenzyme and methyl donor in the synthesis of purine and pyrimidine nucleotides. - This pathway is absolutely necessary for **DNA synthesis**, cellular division, and the maintenance of normal **erythropoiesis**. - Drugs like trimethoprim and methotrexate competitively inhibit DHFR, blocking this pathway and potentially causing megaloblastic anemia or leukopenia, which is why folic acid supplementation is used as a rescue therapy.

동물 종별 용량

Cats

Severe folate deficiency · 0.5-2 mg (total dose) PO once daily · PO · q24h · 1 month
Folate deficiency secondary to exocrine pancreatic insufficiency · 400 micrograms (0.4 mg) PO once daily · PO · q24h
Long-term use of high dose trimethoprim/sulfa (for treating Nocardia) · 2 mg (total dose) PO once daily · PO · q24h
Adjunctive therapy in cats with inflammatory bowel disease · 0.5-1 mg PO q24h (once daily) · PO · q24h · 4-6 weeks · Given with cobalamin at 125-250 micrograms SC or IM once a week.

Horses

Prolonged therapy with antifolate medications (e.g., trimethoprim, pyrimethamine) · 20-40 mg (total dose) PO per day · PO · q24h · Pregnant mares should routinely receive folic acid supplementation during treatment with antifolates.

Dogs

Severe folate deficiency · 0.5-2 mg (total dose) PO once daily · PO · q24h · 1 month
Folate and cobalamin deficiency secondary to inflammatory bowel disease · 5 mg (total dose) PO once daily · PO · q24h · 1-6 months · Given with cyanocobalamin 750 micrograms parenterally once per month.

용량은 면허 수의 전문가를 위한 임상 참고 자료입니다. 항상 최신 라벨과 개별 환자에 대해 확인하십시오.

투여 경로

POIMSCIV

금기

Known intolerance or hypersensitivity to folic acid
Undiagnosed anemias (folic acid therapy may mask the hematologic signs of pernicious anemia/cobalamin deficiency while neurologic damage progresses)

이상반응

Hypersensitivity reactions (rare)
Gastrointestinal effects (rare)
CNS effects such as difficulty sleeping, excitement, or confusion (seen only at very high oral doses in humans, e.g., 15 mg/day)

약물 상호작용

Chloramphenicol · May delay the hematologic response to folic acid.
Methotrexate · Inhibits dihydrofolate reductase; interferes with folic acid utilization.
Trimethoprim · Inhibits dihydrofolate reductase; interferes with folic acid utilization.
Pyrimethamine · Inhibits dihydrofolate reductase; interferes with folic acid utilization.
Phenytoin · Folic acid may decrease serum phenytoin levels, potentially requiring a dosage increase; increased seizure frequency can occur.
Sulfasalazine · May increase the risk for folate deficiency.
Barbiturates · May increase the risk for folate deficiency.
Nitrofurantoin · May increase the risk for folate deficiency.
Primidone · May increase the risk for folate deficiency.

모니터링

Serum folate and cobalamin levels (before and after treatment)
Clinical signs associated with deficiency (e.g., chronic diarrhea, weight loss)
CBC (baseline and ongoing if abnormal, to monitor for anemia)

과용량

Folic acid is relatively **non-toxic**. If an inadvertent overdose occurs, no specific treatment should be required. Excess drug is rapidly metabolized or excreted unchanged in the urine.

VetSheet 약물 레퍼런스는 면허 수의 전문가를 위한 임상 의사결정 보조 도구이며, 전문적 판단이나 제조사의 최신 라벨을 대신하지 않습니다.