메틸테스토스테론

안드로겐 / 단백동화 스테로이드

**메틸테스토스테론(Methyltestosterone)**은 합성 안드로겐 및 단백동화 스테로이드 호르몬입니다. 테스토스테론의 17-알파-알킬화 유도체로, 간의 초회통과대사를 크게 줄여 경구 투여 시 효과적인 흡수를 가능하게 합니다. 수의학에서는 주로 다음과 같은 목적으로 사용됩니다: * **호르몬 반응성 피부질환**: 특히 멜라토닌 치료가 실패한 반려견의 **탈모증 X (Alopecia X)** (모주기 정지). * **번식 관리**: 암컷 반려견의 발정 억제 또는 위임신 치료. * **호르몬 의존성 종양**: 특정 에스트로겐 의존성 유선 종양의 보조 치료. > **임상 요점**: 수의학, 특히 고양이에서의 사용은 논란이 많으며 **심각한 간독성** 위험 때문에 일반적으로 권장되지 않습니다. 고양이는 17-알파-알킬화 안드로겐으로 인한 간 손상에 특히 취약한 것으로 보입니다.

작용 기전: Methyltestosterone acts as an exogenous androgen, binding to intracellular **androgen receptors (AR)** in target tissues. * **Mechanism**: Free methyltestosterone enters cells → binds to cytosolic **AR** → the receptor-ligand complex translocates to the nucleus → binds to specific DNA sequences (androgen response elements) → modulates gene transcription. * **Anabolic Effects**: Stimulates erythropoiesis (increases red blood cell production), enhances nitrogen balance, promotes protein anabolism (requires adequate caloric and protein intake), and increases retention of potassium, sodium, and phosphorus. * **Pharmacokinetic Advantage**: The addition of a **methyl group at the C-17 alpha position** sterically hinders hepatic degradation, providing higher oral bioavailability compared to native testosterone.

동물 종별 용량

Cats

Anti-estrogenic activity, anabolic effects, negative feedback on gonadotropin release · 0.5 mg/kg · PO · once daily · Dose may need to be adjusted, but should not exceed 1 mg/kg. Use is highly controversial due to hepatotoxicity.

Dogs

Alopecia X (when melatonin fails) · 1 mg/kg to a maximum dose of 30 mg (total dose) · PO · once daily · Stop after maximal hair re-growth is noted · Get baseline liver profile and then again one and two months after starting treatment. Can cause hepatotoxicity, aggressive behavior and/or seborrhea.
Testosterone-responsive dermatosis · 1 mg/kg to a maximum dose of 30 mg · PO · every other day · Once dog responds, then every 4-7 days
Suppress estrus in Greyhounds · 5 mg (total dose) · PO · once weekly or divided, two times a week
Estrus suppression · 25-50 mg (total dose) · PO · twice weekly
Anti-estrogenic activity, anabolic effects, negative feedback on gonadotropin release · 0.5 mg/kg · PO · once daily · Dose may need to be adjusted, but should not exceed 1 mg/kg.

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

투여 경로

POBuccal

금기

Hepatic dysfunction or pre-existing liver disease
Pregnancy (Category X - causes fetal masculinization)
Prostate cancer or severe prostatic hypertrophy

이상반응

Hepatotoxicity (elevated liver enzymes, icterus, periportal hepatocyte enlargement)
Virilization of females (clitoral hypertrophy, vaginitis)
Vaginal discharge
Prostatic hyperplasia in males
Increased aggression or behavioral changes
Seborrhea
Premature epiphyseal closure in young animals

약물 상호작용

Cyclosporine · Methyltestosterone may increase serum cyclosporine levels, potentially leading to toxicity.
Insulin · Methyltestosterone may decrease serum glucose levels, reducing insulin requirements.
Oral Antidiabetic Agents · May decrease serum glucose levels, increasing the risk of hypoglycemia.
Warfarin · Methyltestosterone may increase anticoagulant effects, increasing bleeding risk.

모니터링

Baseline and serial hepatic function panels (ALT, AST, ALP, Bilirubin)
Clinical signs of hepatotoxicity (icterus, anorexia, weight loss, vomiting)
Behavioral changes (aggression)
Prostatic evaluation in intact males

과용량

Information on acute toxicity in veterinary species is limited. * **Acute signs**: Nausea, vomiting, and edema are the most likely effects of a single massive overdose. * **Management**: Consider gastrointestinal decontamination if ingestion is recent. Monitor liver function closely with large overdoses and provide supportive care.

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