메티마졸
Methimazole
1-methyl-1,3-dihydro-2H-imidazole-2-thione (Thiamazole)
다른 이름: Tapazole · Felimazole · Northyx · Antitiroide · Danantizol · Favistan · Mercaptizol · Metibasol · Strumazol · Thacapzol · Thycapzol · Thyrozol · Tirodril · Unimazole · Thiafeline · Thyronorm · Thiamazole · Mercazolylum · Methylmercaptoimidazole · Thiamazolum · Tiamazol · Methimazole · Mercazolil
VetSheet 수의사 팀 검수업데이트 2026년 4월 5일근거 기반 수의학 참고자료
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
| 적응증 | 용량 | 경로 | 빈도 | 기간 | 지역 |
|---|---|---|---|---|---|
| As an investigative method to reduce nephrotoxicity associated with cisplatin therapy | 40 mg/kg IV over one minute prior to cisplatin. | IV | once | Prior to cisplatin | 🌎 NA |
| Hyperthyroidism | 2.5-5 mg/dog | PO | q12h | Long-term | 🌍 EU |
- As an investigative method to reduce nephrotoxicity associated with cisplatin therapy: No commercially available parenteral product in USA at time of writing.
- Hyperthyroidism: Dose depends on size.
고양이
| 적응증 | 용량 | 경로 | 빈도 | 기간 | 지역 |
|---|---|---|---|---|---|
| Hyperthyroidism | The starting dose is 2.5 mg administered every 12 hours. Following 3 weeks of treatment, the dose should be titrated to effect based on individual serum total T4 (TT4) levels and clinical response. Dose adjustments should be made in 2.5 mg increments. The maximum total dosage is 20 mg per day divided, not to exceed 10 mg as a single administration. | PO | q12h | Lifelong | 🌎 NA |
| Hyperthyroidism (cats with azotemia or for clients declining radioiodine) | 1.25-5 mg per cat twice daily (start at lower end. | PO | q12h | Lifelong | 🌎 NA |
| Hyperthyroidism (transdermal administration) | 2.5 mg to inner pinna q12h. | topical | q12h | Lifelong | 🌎 NA |
| Hyperthyroidism (gradual titration) | Initially, 2.5 mg (total dose) PO once a day for 2 weeks. If adverse reactions not noted... increase to 2.5 mg PO twice daily and the same parameters are checked in another 2 weeks. The dosage should then be increased every 2 weeks by 2.5 mg per day until serum T4 is between 13 and 26 nmol/L or adverse effects develop. | PO | q24h initially, then q12h | Lifelong | 🌎 NA |
| Hyperthyroidism (based on renal status) | If no signs of renal insufficiency/failure, begin at 5 mg (total dose) PO twice daily in cases with severely increased T4 levels. If renal insufficiency present (or not sure), start at 2.5 mg twice daily. If azotemia and overt renal failure, start at 1.25 mg twice a day. | PO | q12h | Lifelong | 🌎 NA |
| Hyperthyroidism | 2.5 mg/cat | PO | q12h | Long-term | 🌍 EU |
| Hyperthyroidism | Apply transdermal gel to pinna | Topical | q12h | Long-term | 🌍 EU |
- Hyperthyroidism (transdermal administration): Methimazole (50 mg/mL; 5 mg/0.1 mL) in PLO. Person applying should wear gloves or finger cots. Somewhat lower efficacy than PO (67% vs 82% euthyroid at 4 weeks). Lower incidence of GI effects.
- Hyperthyroidism (based on renal status): Monitor in 1-2 weeks (T4, CBC with platelet count, renal blood parameters, urinalysis).
- Hyperthyroidism: 2 to 3 weeks of treatment generally needed to establish euthyroidism. Adjust dose based on T4 monitoring.
- Hyperthyroidism: Used particularly in fractious cats or those with GI side effects. Wear gloves.
용량은 수의사 전문가를 위한 임상 참고자료입니다. 반드시 최신 약물 정보 및 개별 환자에 따라 확인하시기 바랍니다.
개요
메티마졸(Methimazole)은 티오이미다졸 유도체 항갑상선제로, 북미에서 고양이 갑상선 기능 항진증의 내과적 치료를 위한 표준 치료제(Gold standard)로 간주됩니다.
주요 임상 포인트:
- 주요 용도: 고양이 갑상선 기능 항진증 관리. 순환하는 갑상선 호르몬 수치를 효과적으로 낮추어 체중 감소, 다식증, 빈맥 등의 임상 증상을 해결합니다.
- 대체 투여 경로: 알약 투여가 어려운 고양이의 경우, 귓바퀴 안쪽에 바르는 경피용 PLO 겔로 조제할 수 있으며, 이는 경구 투여보다 약간 낮지만 좋은 임상적 효능을 보이고 위장관 부작용이 적을 수 있습니다.
- 연구 목적 용도: 개에서 시스플라틴(cisplatin)으로 인한 신독성을 예방하기 위해 정맥 주사로 사용된 바 있습니다.
- 임상 팁: 메티마졸은 갑상선 기능 항진증을 관리할 뿐 완치시키지는 않습니다. 근본적인 치료(방사성 요오드 또는 갑상선 절제술)를 받지 않는 한 평생 매일 투약해야 합니다.
작용 기전
Methimazole acts directly within the thyroid gland to block the synthesis of thyroid hormones (T3 and T4).
- Mechanism: It actively inhibits the enzyme thyroid peroxidase (TPO).
- Pathway: Inhibition of TPO → prevents the oxidation of iodide to iodine → blocks the incorporation of iodine into tyrosyl residues of thyroglobulin → inhibits the coupling of iodinated tyrosyl residues to form iodothyronine (T3 and T4).
- Important Note: Methimazole has no effect on the release or activity of thyroid hormones that are already formed and stored, or those currently in systemic circulation. This accounts for the 1 to 3 week lag time often seen before serum T4 levels significantly decrease and clinical improvement is noted.
안전성·주의사항
금기사항
- Hypersensitivity to methimazole, carbimazole, or polyethylene glycol
- Autoimmune disease
- Primary liver disease
- Renal failure
- Hematologic disorders or coagulopathies
- Pregnant or lactating queens
- Pregnant queens
- Animals with known hypersensitivity to thiamazole or carbimazole
부작용
- Vomiting
- Depression/Lethargy
- Transient eosinophilia, leukopenia, and lymphocytosis
- Self-induced facial excoriations (pruritus)
- Bleeding/Coagulopathies
- Agranulocytosis
- Positive direct antiglobulin test (DAT)
- Positive ANA (in chronic use >6 months)
- Acquired myasthenia gravis (rare)
- Inappetence / Anorexia
- Jaundice / Hepatopathy
- Cytopenias (thrombocytopenia, leukopenia, anemia)
- Immune-mediated diseases (e.g., myasthenia gravis)
- Dermatological changes (pruritus, facial excoriation, alopecia)
- Decreased GFR (unmasking of renal failure)
주의
Black Box / Handling Warning: Pregnant women, women who may become pregnant, and nursing mothers should wear gloves when handling tablets, litter, or bodily fluids of treated cats.
- Renal Unmasking: Restoring euthyroidism can decrease glomerular filtration rate (GFR) and unmask underlying chronic kidney disease in cats. Careful monitoring of renal values is essential.
- Hematologic & Hepatic Monitoring: Severe adverse effects like agranulocytosis and hepatotoxicity usually occur within the first 3 months. Routine bloodwork monitoring is critical during this phase.
- Nursing: Kittens should be placed on a milk replacer if the mother is receiving the drug, as it is excreted in milk and can cause fetal/neonatal hypothyroidism.
약물 상호작용
Methimazole can reduce hepatic oxidation of benzimidazoles and increase blood levels.
A reduction in dose may be needed when the patient becomes euthyroid.
Potential for increased risk for hepatotoxicity; increased monitoring (LFT's) necessary.
Methimazole may decrease digoxin efficacy, but a reduction in dose may be needed when the patient becomes euthyroid.
Concurrent use of phenobarbital may reduce the clinical effectiveness of methimazole.
A reduction in dose may be needed when the patient becomes euthyroid.
Anticoagulants may be potentiated by methimazole. Increased monitoring of anticoagulant effect is warranted.
Reduce hepatic oxidation and may lead to increased circulating thiamazole concentrations
Thiamazole interferes with radioiodine uptake; must be discontinued prior to I-131 treatment
Concurrent use is not recommended as it confounds dietary management and iodine restriction
모니터링
- Baseline and every 2-3 weeks for the first 3 months: CBC, platelet count, Serum T4
- Liver function tests and ANA if indicated by symptomatology
- After stabilization (at least 3 months): T4 at 3-6 month intervals
- Renal parameters (BUN, Creatinine, USG) to monitor for unmasked kidney disease
- Cats receiving >10 mg/day require more frequent monitoring
- Serum total T4 (measure 4-6 hours post-pill)
- Haematology (CBC for cytopenias)
- Biochemistry (BUN, Creatinine, Liver enzymes)
- Monitor at 3, 6, 10, and 20 weeks after starting therapy, and every 3 months thereafter
약동학
반감기
흡수
In normal cats, oral bioavailability is highly variable (45-98%). There is usually a 1-3 week lag time between starting the drug and significant reductions in serum T4.
분포
Volume of distribution in cats is 0.12-0.84 L/kg. Methimazole actively concentrates in thyroid tissue. High levels cross the placenta and are detected in breast milk.
대사
Undergoes hepatic metabolism.
배설
Eliminated primarily via the kidneys and feces after hepatic metabolism.
과다투여
Acute toxicity from overdosage mirrors severe adverse effects: agranulocytosis, hepatopathy, and thrombocytopenia are the most serious concerns.
Treatment:
- Follow standard protocols for oral ingestion (empty stomach if not contraindicated, administer activated charcoal).
- Provide symptomatic and supportive care (e.g., IV fluids, hepatoprotectants, broad-spectrum antibiotics if neutropenic).
제품
제형
- Oral tablets (sugar-coated, plain, scored)
- Transdermal gel (compounded)
- Intravenous injection (investigational/compounded)
- Oral: 1.25 mg tablet
- Oral: 2.5 mg tablet
- Oral: 5 mg tablet
- Oral: 5 mg/ml solution
- Transdermal gel (named patient basis/compounded)
동물용의약품
- Methimazole Tablets (sugar-coated): 2.5 mg & 5 mg (Felimazole - Dechra)
- Felimazole 1.25 mg, 2.5 mg, 5 mg tablets
- Thiafeline 2.5 mg, 5 mg tablets
- Thyronorm 5 mg/ml oral solution
인용의약품
- Methimazole Tablets (plain & scored): 5 mg, 10 mg, 15 mg & 20 mg (Tapazole, Northyx, generic)
규제 현황
POM-V classification.
POM-V classification.
규제 데이터 없음: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
보관·안정성
Store tablets in well-closed, light-resistant containers at room temperature; protect from moisture. Compounded transdermal PLO gels typically have a guaranteed stability of 2 weeks.
보호자 정보
반려동물 약물 안내
메티마졸(Methimazole)은 고양이의 갑상선 기능 항진증(갑상선이 과도하게 활동하는 질환)을 관리하기 위해 매일 투여하는 약물입니다.
- 작용 원리: 과도한 갑상선 호르몬의 생성을 차단하여 고양이가 정상적인 체중, 심박수 및 행동을 회복하도록 돕습니다.
- 완치제가 아닙니다: 이 약은 질병을 조절하지만 완치시키지는 않습니다. 고양이는 평생 이 약을 복용해야 할 가능성이 높습니다.
- 인내심이 필요합니다: 고양이의 증상이 눈에 띄게 개선되기까지 1~3주가 걸릴 수 있습니다.
투약 팁
- 알약은 매우 쓴맛이 납니다. 수의사의 지시가 없는 한 알약을 부수지 마십시오. 음식에 섞어주면 고양이가 먹기를 거부할 수 있습니다.
- 알약을 먹이기 어렵다면 고양이 귀의 털이 없는 부분에 바를 수 있는 경피용 겔에 대해 수의사와 상담하십시오.
안전 경고
보호자 안전: 메티마졸은 사람의 갑상선 기능과 태아 발달에 영향을 미칠 수 있습니다. 임산부, 임신을 계획 중인 여성, 수유 중인 여성은 알약, 고양이 화장실 모래 또는 치료받는 고양이의 체액을 만질 때 반드시 장갑을 착용해야 합니다.
주의 깊게 살펴볼 사항
고양이에게 다음과 같은 증상이 나타나면 즉시 수의사에게 연락하십시오:
- 구토 또는 식욕 부진 (특히 처음 몇 주 동안)
- 극심한 무기력증 또는 쇠약
- 얼굴이나 목을 심하게 긁는 행동
- 원인을 알 수 없는 멍이나 출혈
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