메르캅토푸린

항종양제 / 면역억제제

**메르캅토푸린(6-MP)**은 티오푸린계 항종양제 및 면역억제제입니다. **임상 요점 및 약리학:** * 이 약물은 **아자티오프린(Azathioprine)**과 밀접한 관련이 있으며, 아자티오프린은 체내에서 메르캅토푸린으로 빠르게 전환되는 전구약물입니다. * 수의학에서 1차 치료제로 사용되는 경우는 드물지만, **림프육종**, **급성 백혈병** 및 중증 면역 매개 질환(**류마티스 관절염** 또는 불응성 궤양성 대장염/염증성 장질환과 같은 난치성 자가면역 질환)의 유용한 보조 치료제로 사용됩니다. * 세포독성 약물이므로 주의 깊게 취급해야 하며, 골수 억제 및 간독성 발생 여부에 대한 철저한 환자 모니터링이 필요합니다.

작용 기전: Mercaptopurine is an inactive prodrug that requires intracellular activation to exert its cytotoxic and immunosuppressive effects. * Mercaptopurine enters the cell and is converted by the enzyme **hypoxanthine-guanine phosphoribosyltransferase (HGPRT)** → **thioinosinic acid (TIMP)**. * TIMP acts as a **purine antagonist**, inhibiting multiple enzymes required for *de novo* purine synthesis. * False nucleotides are incorporated into DNA and RNA → **inhibition of nucleic acid synthesis** → cell cycle arrest and apoptosis. * It primarily affects rapidly dividing cells, strongly inhibiting **humoral immunity** (B-cell function) and, to a lesser extent, cell-mediated immunity.

동물 종별 용량

Dogs

As an immunosuppressant in combination with corticosteroids for treating bullous pemphigoid · 2.2 mg/kg · PO · once daily (q24h), then q48h
For erosive, immune-mediated polyarthritis in combination with corticosteroids · 2 mg/kg · PO · once daily (q24h) for 14-21 days, then q48h (every other day) · 14-21 days initially
For treatment of immune-mediated diseases or acute lymphocytic and granulocytic leukemias · 50 mg/m2 · PO · once daily (q24h) to effect, then every other day (q48h) or as needed

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

투여 경로

금기

Hypersensitivity to mercaptopurine
Pregnancy (teratogenic and mutagenic)

이상반응

Nausea
Anorexia
Vomiting
Diarrhea
Bone marrow suppression (leukopenia, thrombocytopenia, anemia)
Hepatotoxicity
Pancreatitis
Gastrointestinal ulceration (including oral ulcers)
Dermatologic reactions

약물 상호작용

Allopurinol · Decreases hepatic metabolism of mercaptopurine via xanthine oxidase inhibition. Dose of mercaptopurine must be drastically reduced (to 1/4-1/3 of usual dose) if used concurrently.
Aminosalicylates (mesalamine, sulfasalazine) · May increase the risk for mercaptopurine toxicity.
Hepatotoxic drugs (halothane, ketoconazole, valproic acid, phenobarbital, primidone, doxorubicin) · Increased risk of hepatotoxicity; use cautiously together.
Immunosuppressive drugs (azathioprine, cyclophosphamide, corticosteroids) · Increased risk of severe infection due to additive immunosuppression.
Myelosuppressive drugs (antineoplastics, chloramphenicol, flucytosine, amphotericin B, colchicine, trimethoprim/sulfa) · Additive bone marrow depression; use with extreme caution.
Vaccines, live · Increased risk of vaccine-induced infection; use with caution or avoid during therapy.
Warfarin · Mercaptopurine may reduce the anticoagulant effect of warfarin.

모니터링

Hemograms (including platelets): Monitor closely; initially every 1-2 weeks, then every 1-2 months on maintenance therapy. (Note: If WBC drops to 5,000-7,000 cells/mm3, consider reducing dose by 25%. If WBC drops below 5,000 cells/mm3, discontinue until leukopenia resolves).
Liver function tests (ALT, AST, ALP, Bilirubin)
Serum amylase (if pancreatitis is suspected)
Clinical efficacy and signs of toxicity

과용량

Toxicity may present **acutely** (severe GI effects like vomiting and diarrhea) or be **delayed** (bone marrow depression, hepatotoxicity, gastroenteritis). * **Treatment**: If ingestion was recent, use standard protocols to empty the GI tract (emesis, activated charcoal). Provide aggressive supportive care (IV fluids, antiemetics, broad-spectrum antibiotics if neutropenic, and potentially blood transfusions for severe myelosuppression).

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