메게스트롤 아세테이트

Megestrol Acetate

17-alpha-acetoxy-6-dehydro-6-methylprogesterone

다른 이름: Ovaban · Megace · Ovarid · BDH-1298 · compound 5071 · megestroli acetas · NSC-71423 · SC-10363 · Acestrol · Borea · Endace · Gynodal · Maygace · Megastrol · Megefren · Megestat · Megestil · Megestin · Megostat · Meltonar · Meprogest · Mestrel · Niagestine · Prazoken · Varigestrol

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

2.2 mg/kg once daily for 8 days starting during the first 3 days of proestrus. May be prolonged with 2.2 mg/kg/day for 4 days, then 0.55 mg/kg/day for 16-20 days.PO· q24h· 8-24 days

체중— 🐕

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
To halt cycle in proestrus	2.2 mg/kg once daily for 8 days starting during the first 3 days of proestrus. May be prolonged with 2.2 mg/kg/day for 4 days, then 0.55 mg/kg/day for 16-20 days.	PO	q24h	8-24 days	🌎 NA
To postpone an anticipated cycle	0.55 mg/kg/day for 32 days, beginning at least 7 days prior to proestrus	PO	q24h	32 days	🌎 NA
To delay an anticipated heat during anestrus	0.55 mg/kg PO for 32 days initiated 7 days prior to proestrus.	PO	q24h	32 days	🌎 NA
Estrus suppression (general)	2 mg/kg PO once daily for 8 consecutive days	PO	q24h	8 days	🌎 NA
Temporary estrus postponement (general)	0.5 mg/kg PO once daily in late anestrus	PO	q24h	Variable	🌎 NA
Benign prostatic hypertrophy	0.5 mg/kg PO daily for 4-8 weeks	PO	q24h	4-8 weeks	🌎 NA
Benign prostatic hypertrophy	0.55 mg/kg PO daily	PO	q24h	Variable	🌎 NA
Benign prostatic hypertrophy	0.1-0.5 mg/kg per day for 3-8 weeks	PO	q24h	3-8 weeks	🌎 NA
Pseudocyesis (false pregnancy)	0.5 mg/kg PO once daily for 8 days	PO	q24h	8 days	🌎 NA
To prevent vaginal hyperplasia development	2.2 mg/kg PO for 7 days early in proestrus	PO	q24h	7 days	🌎 NA
Treatment of severe galactorrhea	0.55 mg/kg PO once daily for 7 days	PO	q24h	7 days	🌎 NA
Adjunctive treatment of aggressive or unacceptable masculine behavior	1.1-2.2 mg/kg PO once daily for 2 weeks, then 0.5-1.1 mg/kg once daily for 2 weeks.	PO	q24h	4 weeks	🌎 NA

To halt cycle in proestrus: Bitch must be controlled until behavioral signs of estrus disappear.
To delay an anticipated heat during anestrus: Recommend doing vaginal cytology prior to therapy. Do not repeat therapy more often than once every 6 months.
Benign prostatic hypertrophy: Best used to maintain breeding potential for short time prior to castration; use with caution.
Adjunctive treatment of aggressive or unacceptable masculine behavior: Should be used with behavior modification.

고양이

적응증	용량	경로	빈도	기간	지역
Suppression of estrus (in anestrus)	5 mg/cat PO every 2 weeks or 2.5 mg/cat per week (better if divided into 2 doses given every 3.5 days)	PO	q7-14d	Variable	🌎 NA
Suppression of estrus (in proestrus)	5 mg/cat per day for 4 days, then 5 mg PO every 2 weeks.	PO	q24h then q14d	Variable	🌎 NA
Suppression of estrus (behavioral estrus)	5 mg/day PO until estrus stops (generally within 3-5 days), then 2.5-5 mg PO once weekly for 10 weeks	PO	q24h then q7d	10+ weeks	🌎 NA
Postponement of estrus (started during diestrus)	2.5 mg PO daily for 8 weeks	PO	q24h	8 weeks	🌎 NA
Postponement of estrus (started during anestrus)	2.5 mg PO once weekly for up to 18 months.	PO	q7d	Up to 18 months	🌎 NA
Prevention of estrus	5 mg daily PO for 3 days as soon as behavioral signs of estrus are seen	PO	q24h	3 days	🌎 NA
Idiopathic feline miliary dermatitis	2.5-5 mg once every other day, followed by weekly maintenance dosages.	PO	q48h then q7d	Variable	🌎 NA
Appetite stimulant	0.25-0.5 mg/kg q24h for 3-5 days, then q48-72h	PO	q24h then q48-72h	Variable	🌎 NA
Alternative treatment for immune-mediated skin diseases	2.5-5 mg PO once daily for 10 days, then every other day	PO	q24h then q48h	Variable	🌎 NA
Adjunctive therapy of eosinophilic granulomas	0.5 mg/kg PO once daily for 2 weeks, then twice weekly as needed	PO	q24h then twice weekly	Variable	🌎 NA
Eosinophilic ulcers	5-10 mg PO every other day for 10-14 doses, then every 2 weeks as needed	PO	q48h then q14d	Variable	🌎 NA
Feline atopy ('last ditch' alternative)	2.5-5 mg per cat PO every 48 hours for 1-3 weeks. This dose is then used once weekly.	PO	q48h then q7d	Variable	🌎 NA
Feline plasma cell gingivitis	2.5 mg PO once daily for 10 days, then once every other day for 5 treatments, then as needed	PO	q24h then q48h	Variable	🌎 NA
Feline endocrine alopecia (FEA)	5 mg PO every second to third day initially, then 2.5 mg PO once to twice weekly	PO	q48-72h then 1-2x weekly	Variable	🌎 NA
Feline psychogenic alopecia and dermatitis	2.5-5 mg every other day initially, then taper to the lowest maintenance dosage possible, given weekly as needed	PO	q48h then q7d	Variable	🌎 NA
Persistent hematuria and urethritis in a non-obstructed cat	2.5-5 mg PO once daily to every other day (with prednisone: 2.5-5 mg PO daily)	PO	q24-48h	Variable	🌎 NA
Urine marking, intraspecies aggression, anxiety	2 mg/kg/day for 5 days, then 1 mg/kg/day for 5 days, then 0.5 mg/kg/day for 5 days	PO	q24h	15 days	🌎 NA
To reduce marking in neutered male cats	2.5-10 mg (total dose) per cat PO once daily for one week, then reduce to once or twice weekly.	PO	q24h then 1-2x weekly	Variable	🌎 NA
Urine marking, intraspecies aggression, anxiety	5 mg per cat once daily for 2 weeks, then wean to lowest effective maintenance dose.	PO	q24h	Variable	🌎 NA

Postponement of estrus (started during anestrus): Recommend allowing cat to have a cycle (unmedicated) before beginning another treatment cycle.
Prevention of estrus: Next estrus period will occur in approximately 4 weeks.
Idiopathic feline miliary dermatitis: Reserve use for severe cases; explain risks to owner and do not exceed 2.5 mg per week during maintenance phase.
Eosinophilic ulcers: Alone or in combination with methylprednisolone acetate.
Feline endocrine alopecia (FEA): Secondary therapy (thyroid hormone replacement first choice).
Persistent hematuria and urethritis in a non-obstructed cat: Adjunctive therapy.
To reduce marking in neutered male cats: When all other drugs have been unsuccessful.
Urine marking, intraspecies aggression, anxiety: Has poor efficacy in neutered males (50%) and spayed females (10%); many potential adverse effects.

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

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개요

메게스트롤 아세테이트는 강력한 합성 프로게스틴으로, 유의미한 항에스트로겐 및 내인성 글루코코르티코이드 특성을 가지고 있습니다.

과거에는 특히 고양이의 다양한 피부 및 행동 질환에 널리 사용되었으나, 심각하고 때로는 비가역적인 부작용(심각한 부신피질 억제 및 의인성 당뇨병 등)의 위험이 높아 현재 고양이에서의 사용은 크게 감소하였습니다.

개에서는 암컷의 발정 지연 및 위임신 완화 목적으로 FDA 승인을 받았으며, 수컷의 양성 전립선 비대증(BPH)에 오프라벨로 사용됩니다. 인의학에서는 식욕 촉진제 및 진행성 유방암 또는 자궁내막암의 완화 치료에 사용됩니다.

작용 기전

Megestrol acetate exerts its effects through multiple receptor pathways:

Progesterone Receptors: Binds to progestin receptors → provides negative feedback to the hypothalamus and pituitary → inhibits the release of GnRH, LH, and FSH → suppresses estrus and ovulation.
Glucocorticoid Receptors: Possesses significant intrinsic glucocorticoid activity → binds to glucocorticoid receptors → causes profound suppression of the hypothalamic-pituitary-adrenal (HPA) axis and induces insulin resistance.
Anti-estrogenic Activity: Modifies target tissue response to estrogens.

Clinical Pearl: Unlike some other progestins, megestrol acetate does not possess significant anabolic or masculinizing effects on the developing fetus.

안전성·주의사항

금기사항

Uterine disease (e.g., pyometra, endometritis)
Diabetes mellitus
Mammary neoplasias
Prior to the first estrous cycle in dogs
Anestrus therapy in dogs with abnormal cycles
During diestrus or in the presence of uterine hemorrhage
Treatment of pseudopregnancy in bitches (per manufacturer, though off-label protocols exist)

부작용

Profound adrenocortical suppression (especially in cats)
Transient or permanent diabetes mellitus
Cystic endometrial hyperplasia (CEH) and pyometra
Mammary hypertrophy and neoplasia
Increased appetite and weight gain
Polydipsia and polyuria (PU/PD)
Lethargy and personality changes
Hepatotoxicity (rare)
Acromegaly (dogs)
Lactation (rare)

주의

Black Box Warning Equivalent: Megestrol acetate can induce profound, life-threatening adrenocortical suppression and iatrogenic Addisonian crisis, particularly in cats.

Adrenal Suppression: Because of its glucocorticoid activity, patients may require exogenous stress-dose steroids during periods of trauma, surgery, or severe illness.
Reproductive Risks: High risk of inducing cystic endometrial hyperplasia (CEH) and pyometra. A thorough reproductive history, physical exam, mammary palpation, and vaginal cytology are strongly recommended before initiating therapy for reproductive control.
Infection Risk: May exacerbate latent viral infections (e.g., Feline Herpesvirus-1).
Human Safety: Pregnant women should handle this medication with extreme caution (FDA Category X in early pregnancy).

약물 상호작용

Corticosteroids

Concurrent long-term use may exacerbate adrenocortical suppression and increase the risk of diabetes mellitus.

Rifampin

May decrease progestin activity due to microsomal enzyme induction, resulting in increased progestin metabolism.

모니터링

Body weight
Blood glucose (draw baseline before therapy)
Mammary gland development and appearance (nodules/hypertrophy)
Adrenocortical function (ACTH stimulation test if indicated)
Liver enzymes (especially with long-term treatment)
Clinical efficacy

약동학

반감기

개8 days

흡수

Well absorbed from the gastrointestinal tract.

분포

Widely distributed. Detectable amounts of progestins enter the milk of nursing mothers.

대사

Appears to be metabolized completely in the liver to conjugates and free steroids.

배설

Excreted primarily via urine and feces.

과다투여

Acute toxicity from overdosage has not been reported. In humans, massive doses (up to 800 mg/day) caused no observable acute adverse reactions.

Chronic Toxicity in Dogs:

Dosages of 0.1-0.25 mg/kg/day PO for 36 months yielded no gross abnormalities, but histologically, cystic endometrial hyperplasia (CEH) was noted (resolved when therapy was discontinued).
Dosages of 0.5 mg/kg/day PO for 5 months caused reversible uterine hyperplasia.
Dosages of 2 mg/kg/day demonstrated early cystic endometritis within 64 days.

제품

제형

Oral tablets
Oral suspension

동물용의약품

Megestrol Acetate Oral Tablets: 5 mg, 20 mg (Ovaban)

인용의약품

Megestrol Acetate Tablets: 20 mg, 40 mg (Megace)
Megestrol Acetate Suspension: 40 mg/mL, 125 mg/mL (Megace, Megace ES)

규제 현황

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

보관·안정성

Store tablets in well-closed containers at a temperature of less than 40°C. The veterinary manufacturer recommends storing the tablets from 2°-30°C (36°-86°F). Tablets may be crushed and administered with food.

보호자 정보

메게스트롤 아세테이트는 강력한 호르몬 약물입니다. 효과적일 수 있지만, 특히 고양이에게는 심각한 위험이 따릅니다.

위험성 이해：이 약물은 당뇨병, 심각한 자궁 감염(자궁축농증), 부신 억제 등 심각한 부작용을 일으킬 수 있습니다.
면밀한 관찰：반려동물의 음수량과 배뇨량을 주의 깊게 관찰하십시오. 물을 너무 많이 마시거나 소변을 많이 본다면 당뇨병의 징후일 수 있으므로 즉시 수의사에게 연락하십시오.
신체 변화：반려동물의 유선(배 부위)에 붓기, 멍울 또는 분비물이 있는지 정기적으로 확인하십시오. 변화가 있으면 수의사에게 알리십시오.
행동 및 활력：극심한 무기력, 쇠약 또는 갑작스러운 행동 변화가 있는지 주의하십시오.
갑작스러운 중단 금지：반려동물이 이 약을 장기간 복용한 경우, 신체가 적응할 시간이 필요하므로 수의사와 상의 없이 갑자기 약을 중단하지 마십시오.
사람에 대한 안전：임산부는 이 약물의 취급을 피해야 합니다.

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