VetSheet

메토트렉세이트

Methotrexate

Methotrexate sodium

항종양제 / 면역억제제 (대사길항제)POIVIMIntrathecalSC개고양이

다른 이름: Rheumatrex · Trexall · Methotrexate LPF · MTX · Amethopterin · 4-Amino-4-deoxy-10-methylpteroyl-L-glutamic acid · 4-Amino-10-methylfolic acid · CL-14377 · alpha-methopterin · methotrexatum · metotrexato · NSC-740 · WR-19039

VetSheet 수의사 팀 검수업데이트 2026년 4월 5일근거 기반 수의학 참고자료

2.5-5 mg/m2 PO twice a weekPO· twice a week

체표면적(mg/m²) 기반 용량입니다. 투여 전에 체중을 체표면적으로 환산해야 합니다.

용량은 수의사 전문가를 위한 임상 참고자료입니다. 반드시 최신 약물 정보 및 개별 환자에 따라 확인하시기 바랍니다.

동물 종별 용량

🌎 NA — North America🌍 EU — Europe

개

적응증용량경로빈도기간지역
As part of the LMP protocol for maintenance of canine lymphoma2.5-5 mg/m2 PO twice a weekPOtwice a week—🌎 NA
In combination with other antineoplastics (per protocol)5 mg/m2 PO twice weekly or 0.8 mg/kg IV every 21 days; alternatively 2.5 mg/m2 PO dailyPO/IVtwice weekly, every 21 days, or daily—🌎 NA
  • As part of the LMP protocol for maintenance of canine lymphoma: Given with Chlorambucil 20 mg/m2 PO every 15 days and Prednisone 20 mg/m2 PO every other day. When Vincristine is added it is at a dose of 0.5-0.7 mg/m2 and is given every 15 days alternating weeks with the chlorambucil.

고양이

적응증용량경로빈도기간지역
For susceptible neoplastic diseases (usually as part of a multi-drug protocol)2.5 mg/m2 PO 2-3 times weekly; 0.3-0.8 mg/m2 IV every 7 daysPO/IV2-3 times weekly (PO) or every 7 days (IV)—🌎 NA
For non-suppurative cholangitis/cholangiohepatitis (CCHC) syndrome with fibrosisA total dose of 0.4 mg per cat total dose given on one day in three divided doses: 0.26 mg at hour zero, 0.13 mg at the 12 and 24 hour dosing. Repeat every 7-10 days.PODivided over 24 hours, repeated every 7-10 days—🌎 NA
  • For non-suppurative cholangitis/cholangiohepatitis (CCHC) syndrome with fibrosis: Use in conjunction with ursodeoxycholic acid (15 mg/kg PO q24h) and folate (0.25 mg/kg PO q24h).

용량은 수의사 전문가를 위한 임상 참고자료입니다. 반드시 최신 약물 정보 및 개별 환자에 따라 확인하시기 바랍니다.

진료 중이신가요? VetSheet의 AI가 약물, 용량, 투여 기간을 구조화된 진료 기록에 바로 기입합니다.VetSheet 작동 방식 보기

개요

메토트렉세이트(MTX)는 강력한 ​엽산 길항제​로, 수의 종양학에서 주로 개와 고양이의 ​림프증식성 질환​(예: 림프종) 및 특정 고형암 치료에 사용됩니다.

항종양 특성 외에도 상당한 ​면역 억제​ 능력을 가지고 있어, 표준 프레드니솔론이나 클로람부실 치료에 반응하지 않는 고양이의 비화농성 담관염/담관간염과 같은 난치성 면역 매개 질환에 유용한 치료 옵션이 됩니다.

​임상 요점:​ MTX는 치료 지수가 매우 좁고 신장 배설에 크게 의존하므로, 심각한 독성을 예방하기 위해 환자의 수화 상태와 신장 기능이 가장 중요합니다. 빠르게 분열하는 세포에 매우 독성이 강하여 위장관 상피와 골수가 특히 부수적 손상에 취약합니다.

작용 기전

Methotrexate is an S-phase specific antimetabolite. It acts by competitively and irreversibly inhibiting the enzyme ​dihydrofolate reductase (DHFR)​.

  • Folic acid → (via DHFR) → Dihydrofolate → (via DHFR) → Tetrahydrofolate (active form).
  • By blocking DHFR, MTX prevents the reduction of dihydrofolate to tetrahydrofolate.
  • Tetrahydrofolate is an essential cofactor for the synthesis of purines and pyrimidines (specifically thymidylate).
  • The depletion of these precursors halts DNA, RNA, and protein synthesis, ultimately leading to apoptosis in rapidly proliferating cells (e.g., neoplasms, bone marrow, GI tract epithelium).

​Note:​ DHFR has a much greater affinity for MTX than for folic acid. Therefore, coadministration of folic acid will not reverse MTX toxicity. Leucovorin calcium (a derivative of tetrahydrofolic acid that bypasses the blocked enzyme) is required as a rescue agent.

안전성·주의사항

금기사항

  • Preexisting bone marrow depression
  • Severe hepatic insufficiency
  • Severe renal insufficiency
  • Hypersensitivity to the drug
  • Pregnancy (Teratogenic/Embryotoxic - FDA Category X)
  • Nursing mothers
  • Pre-existing severe bone marrow suppression
  • Severe renal impairment
  • Severe hepatic impairment
  • Pregnancy and lactation (teratogenic and embryotoxic)
  • Patients with significant third-space fluid accumulations (e.g., ascites, pleural effusion)

부작용

  • Nausea
  • Inappetence (especially in cats)
  • GI toxicity (ulcers, mucosal sloughing, stomatitis)
  • Hematopoietic toxicity / Myelosuppression (nadir at 4-6 days)
  • Hepatopathy
  • Renal tubular necrosis
  • Depigmentation
  • Pulmonary infiltrates and fibrosis
  • CNS toxicity (encephalopathy) if given intrathecally
  • Anaphylaxis (rare)
  • Myelosuppression (neutropenia, thrombocytopenia, anemia)
  • Gastrointestinal toxicity (anorexia, vomiting, diarrhea, stomatitis)
  • Hepatotoxicity (elevated liver enzymes)
  • Nephrotoxicity (especially at high doses due to tubular precipitation)
  • Alopecia (rare in most animals, but possible in continuously growing coats)

주의

Use with extreme caution in patients susceptible to or with preexisting clinical signs of MTX adverse reactions. ​Handling Precautions:​ Wear gloves or immediately wash hands after handling. Gloves are particularly important if handling split, broken, or crushed tablets. Preparation of intravenous solutions should ideally be performed in a vertical laminar flow hood to avoid human exposure. Teratogenic and may affect spermatogenesis.

약물 상호작용

Amiodarone

Prolonged PO administration (>2 weeks) may inhibit MTX metabolism

Asparaginase

Given concomitantly with MTX may decrease MTX efficacy

Azathioprine

Potential for increased risk for hepatic toxicity

Chloramphenicol

May displace MTX from plasma proteins increasing risk for toxicity, but also may reduce MTX absorption and enterohepatic recirculation

Cisplatin

May have synergistic action with MTX, but alter the renal elimination of MTX

Cyclosporine

May increase MTX levels

Folic Acid

May reduce MTX efficacy, but folate deficiency increases MTX toxicity

Neomycin (oral)

May decrease the absorption of oral methotrexate if given concomitantly

NSAIDs / Salicylates

Severe hematologic and GI toxicity risk; use caution in dogs also on MTX

PenicillinsModerate

May decrease MTX renal elimination

ProbenecidMajor

May inhibit the tubular secretion of MTX and increase its half-life

Pyrimethamine

A similar folic acid antagonist; may increase MTX toxicity and should not be given to patients receiving MTX

Retinoids

Potential for increased risk for hepatic toxicity

Sulfasalazine

Potential for increased risk for hepatic toxicity

Sulfonamides

May displace MTX from plasma proteins increasing risk for toxicity

Tetracyclines

May displace MTX from plasma proteins increasing risk for toxicity, but also may reduce MTX absorption and enterohepatic recirculation

Theophyllines

MTX may reduce theophylline elimination

Trimethoprim/Sulfa

Rarely, may increase myelosuppression of MTX

Vaccines, Live

Live virus vaccines should be used with caution, if at all during therapy

NSAIDsMajor

Decreased renal clearance of methotrexate, leading to increased serum levels and severe toxicity.

Trimethoprim-sulfamethoxazoleMajor

Additive antifolate effects, significantly increasing the risk of severe bone marrow suppression.

OmeprazoleModerate

May delay the elimination of methotrexate.

모니터링

  • Efficacy of treatment
  • Clinical signs of GI irritation and ulceration
  • Complete blood counts (with platelets) weekly early in therapy, then every 4-6 weeks (Discontinue if WBC <4000/mm3 or platelets <100,000/mm3)
  • Baseline and ongoing renal function tests
  • Baseline and ongoing hepatic function tests (liver enzymes)
  • Complete Blood Count (CBC) - baseline and prior to each dose (monitor for nadir)
  • Renal function panel (BUN, Creatinine, Urinalysis)
  • Hepatic enzymes (ALT, AST, ALP, Bilirubin)
  • Clinical signs of gastrointestinal toxicity (vomiting, diarrhea, anorexia)
  • Hydration status

약동학

반감기

고양이Unknown개<10 hours (generally between 2-4 hours)

흡수

Well absorbed from the GI tract after oral administration of dosages <30 mg/m2 with a bioavailability of about 60%. Peak levels occur within 4 hours after oral dosing, and between 30 minutes and 2 hours after IM injection.

분포

Widely distributed in the body and actively transported across cell membranes. Highest concentrations in kidneys, spleen, gallbladder, liver, and skin. Does not reach therapeutic levels in CSF unless given intrathecally. About 50% bound to plasma proteins and crosses the placenta.

대사

Minimal hepatic metabolism is noted; primarily excreted unchanged.

배설

Excreted almost entirely by the kidneys via both glomerular filtration and active transport.

과다투여

Acute overdosage in dogs is associated with severe exacerbations of adverse effects, particularly myelosuppression and acute renal failure. Acute tubular necrosis occurs secondary to drug precipitation in the renal tubules.

  • ​Toxicity Thresholds:​ In dogs, the maximally tolerated dose is reported to be 0.12 mg/kg q24h for 5 days. A dose of 10 mg/kg is considered lethal if leucovorin rescue is not performed.
  • ​Decontamination:​ Empty the gut and prevent absorption using standard protocols if ingestion is recent. Oral neomycin has been suggested to help prevent intestinal absorption.
  • ​Renal Protection:​ Forced alkaline diuresis should be considered to minimize renal damage. Maintain urine pH between 7.5-8 by adding 0.5-1 mEq/kg of sodium bicarbonate per 500 mL of IV fluid.
  • ​Antidote:​ Leucovorin calcium is the specific therapy for MTX overdoses. It must be given as soon as possible (preferably within the first hour, definitely within 48 hours). Dogs treated with leucovorin at 15 mg/m2 every 3 hours IV for 8 doses, then IM q6h for 8 doses were able to tolerate very high MTX doses.

제품

제형

  • Tablets
  • Injection solution
  • Powder for injection
  • 2.5 mg oral tablet
  • 10 mg oral tablet

인용의약품

  • Methotrexate Sodium Tablets (plain & scored): 2.5 mg, 5 mg, 7.5 mg, 10 mg & 15 mg
  • Methotrexate Sodium Injection: 25 mg/mL (as base) in various vial sizes
  • Methotrexate Powder for Injection, lyophilized: 1 gram preservative free in single-use vials
  • Matrex 2.5 mg tablets
  • Methotrexate 2.5 mg tablets
  • Methotrexate 10 mg tablets

규제 현황

European Union✓ 승인됨처방전의약품EMA
🐕 Dogs🐈 Cats

Human authorized products often used off-label under the cascade.

United Kingdom✓ 승인됨처방전의약품 · POMVMD
🐕 Dogs🐈 Cats

Prescription Only Medicine. Handled under cascade regulations.

규제 데이터 없음: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU

보관·안정성

Methotrexate sodium tablets should be stored at room temperature (15-30°C) in well-closed containers and protected from light. The injection and powder for injection should be stored at room temperature (15-30°C) and protected from light.

보호자 정보

​경고: 항암 화학요법제​ 이 약물은 독성이 매우 강하며 잘못 취급할 경우 사람에게 위험할 수 있습니다.

  • ​취급 안전:​ 알약(특히 부수거나 쪼갠 알약)을 투여할 때는 항상 일회용 장갑을 착용하십시오. 장갑을 사용하지 않은 경우 취급 후 즉시 손을 철저히 씻으십시오. 임산부나 면역력이 저하된 사람은 이 약물의 취급을 피해야 합니다.
  • ​독성 위험:​ 이 약물로 인해 약물 관련 사망을 포함한 심각한 독성이 발생할 가능성이 있음을 인지해야 합니다.
  • ​수의사에게 연락해야 할 때:​ 반려동물에게 극심한 우울증, 무기력, 비정상적인 출혈(혈변, 검은 타르 변 포함), 멍, 구토 또는 식욕 부진 등의 임상 증상이 나타나면 즉시 수의사에게 연락하십시오.
  • ​수유:​ 이 약물을 복용 중인 반려동물은 새끼에게 젖을 먹여서는 안 됩니다. 인공유로 대체하십시오.

VetSheet 의약품 참고자료는 수의사 전문가의 임상 의사결정 지원을 위한 것이며, 전문적 판단이나 제조사의 최신 약물 정보를 대체할 수 없습니다.