メラトニン
Melatonin
N-acetyl-5-methoxytryptamine
別名: Regulin · Ferretonin · Dermatonin · Benedorm · Buenas Noches · Cronocaps · HT90 · Melapure · Melatol · Repentil · Revenox · Transzone · Circadin · n-acetyl-5-methoxytryptamine · MLT · pineal hormone · Melatonina
VetSheet 獣医チームが監修更新日 2026年4月5日エビデンスに基づく獣医学リファレンス
用量は獣医専門家向けの臨床参考資料です。必ず最新の医薬品情報および個別症例に基づいて確認してください。
動物種別用量
🌎 NA — North America🌍 EU — Europe
犬
| 適応 | 用量 | 経路 | 頻度 | 期間 | 地域 |
|---|---|---|---|---|---|
| Alopecia-X, canine pattern baldness, or recurrent flank alopecia (experimental) | One to four 12 mg implants SC. Retreatment may be necessary once or twice a year. Alternatively, 3-6 mg PO q8-12h. | SC/PO | q8-12h (PO) or 1-2 times/year (SC) | — | 🌎 NA |
| Canine recurrent flank alopecia or seasonal flank alopecia | 2-3 mg per dog (up to 10 mg used) | PO | q24h for 3-5 days weekly or monthly, or daily | Improvement usually seen in 1 month, maximal in 3 months | 🌎 NA |
| Alopecia X | 3-6 mg (total dose) | PO | 2-3 times a day | 3 months | 🌎 NA |
| Color dilution alopecia | 1.5-6 mg | PO | 2-3 times a day | Stop when good re-growth occurs | 🌎 NA |
| Alopecia-X | 3 mg-12 mg (depending on size) | PO | 2 to 3 times a day | At least 4 months | 🌎 NA |
| Sleep disorders (nocturnal activity) | 3-6 mg (total dose) | PO | q12-24h | — | 🌎 NA |
| Sleep aid, fears, and phobias | 0.1 mg/kg | PO | q8h | — | 🌎 NA |
| Idiopathic vacuolar hepatopathy | 4-6 mg/day (total dose for dogs <= 15 kg) | PO | q24h | — | 🌎 NA |
| Hair cycling disorders (e.g., Alopecia X, seasonal flank alopecia) | 3-6 mg | PO | q8h | 4-6 week trial | 🌍 EU |
- Alopecia-X, canine pattern baldness, or recurrent flank alopecia (experimental): Recommend having owners sign a release form noting the 'experimental' nature of treatment.
- Alopecia X: Neutering recommended initially. Treat until maximal response is noted and discontinue. Re-institute if signs recur.
- Idiopathic vacuolar hepatopathy: May improve liver enzymes and hepatic changes.
- Hair cycling disorders (e.g., Alopecia X, seasonal flank alopecia): If no growth is noted after 4-6 weeks, discontinue. May need repeating next year for seasonal flank alopecia.
猫
| 適応 | 用量 | 経路 | 頻度 | 期間 | 地域 |
|---|---|---|---|---|---|
| Sleep disorders (nocturnal activity) | 3-12 mg (total dose) | PO | q12-24h | — | 🌎 NA |
| Suppression of estrus | 18 mg implant | SC | Once | Suppresses estrus for 2-4 months | 🌎 NA |
フェレット
| 適応 | 用量 | 経路 | 頻度 | 期間 | 地域 |
|---|---|---|---|---|---|
| Adjunctive treatment of adrenal disease | 0.5-1 mg per ferret | PO | q24h (7-9 hours after sunrise) | — | 🌎 NA |
| Adjunctive treatment of adrenal disease | 1-2 mg per ferret | PO | q24h | — | 🌎 NA |
- Adjunctive treatment of adrenal disease: Can also use 5.4 mg implant which releases over 3-4 months. Better response in fall/winter.
- Adjunctive treatment of adrenal disease: Or use 5.4 mg implant. May cause excessive drowsiness in ferrets under 600 grams.
豚
| 適応 | 用量 | 経路 | 頻度 | 期間 | 地域 |
|---|---|---|---|---|---|
| Reduction of gastric ulcers in young pigs | 5 mg/kg in feed | PO | Continuous in feed | — | 🌎 NA |
用量は獣医専門家向けの臨床参考資料です。必ず最新の医薬品情報および個別症例に基づいて確認してください。
概要
メラトニンは松果体から分泌される天然ホルモンで、主に睡眠・覚醒サイクルの調節に関与します。獣医療では、犬の脱毛症（脱毛症Xなど）、犬猫の睡眠・行動障害、フェレットの副腎疾患の補助治療などに使用されます。
作用機序
Melatonin is involved in the neuroendocrine control of photoperiod-dependent molting, hair growth, and pelage color.
- Hair Growth: It stimulates winter coat growth; spring shedding occurs when melatonin levels decrease. The exact mechanism is unknown but may involve direct effects on the hair follicle or alteration of prolactin and/or melanocyte-stimulating hormone (MSH) secretion.
- Endocrine Effects: Increases serum prolactin and growth hormone levels, and enhances the response to growth hormone-releasing hormone. Long-term use may decrease luteinizing hormone (LH).
- Antioxidant: Acts as a potent free radical scavenger.
安全性・警告
禁忌
- Pregnancy
- Sexually immature animals
- Hepatic insufficiency (in humans)
- No information available
有害事象
- Sedation or drowsiness
- Altered sex hormone secretion and fertility
- Sterile abscesses at subcutaneous implant sites
- No information available in monograph (generally well tolerated, may cause mild sedation)
注意事項
Use with caution in patients with renal impairment. Because of its CNS depressant qualities, it should be used cautiously in patients with a history of cerebrovascular disease, depression, or neurological disorders. Animals nursing young may not benefit from implant therapy.
医薬品相互作用
Melatonin may potentiate sedative effects
Melatonin may potentiate neuromuscular blocking effects
監視
- Clinical efficacy (e.g., hair regrowth, improved sleep patterns)
- Hair regrowth (evaluate after 4-6 weeks of therapy)
薬物動態
吸収
No specific information located in veterinary species.
分布
No specific information located.
代謝
Cleared hepatically (in humans).
消失
No specific information located.
過剰投与
Little information is available; it is unlikely to cause significant morbidity after a single overdose. Treat symptomatically if profound sedation occurs.
製品
製剤
- Oral tablets
- Oral capsules
- Oral liquid
- Subcutaneous implants
- 2 mg tablet
- 3 mg tablet
- Over-the-counter (OTC) formulations of various sizes
動物用医薬品
- Ferretonin (Melatek) 5.4 mg implant for ferrets
- Dermatonin (Melatek) 8 mg, 12 mg, 18 mg implants for dogs
- Regulin 18 mg implant for sheep/goats
ヒト用医薬品
- Melatonin tablets (0.5 mg to 3 mg)
- Sustained release capsules (3 mg)
- Oral liquid (500 mcg/mL)
- Circadin 2 mg tablets
- Circadin 3 mg tablets
規制ステータス
Circadin is a Prescription Only Medicine (POM)
Circadin is a Prescription Only Medicine (POM)
規制データなし: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
保管・安定性
Store at room temperature in tight containers unless otherwise labeled.
飼主向け情報
メラトニンは、ペットの特定の脱毛症、睡眠障害、不安の治療に使用されるサプリメントです。
- 投与方法: 効果を得るためには、獣医師の指示通りに正確に投与する必要があります。投与のタイミング（夜間など）が重要です。
- 期待される効果: 脱毛症の場合、改善が見られるまでに数ヶ月かかることがあります。
- 安全性: 獣医療では比較的「実験的」な使用ですが、一般的に非常に安全です。最も一般的な副作用は軽度の眠気です。
- 購入について: 市販のサプリメントであるため品質にばらつきがあります。獣医師が推奨する信頼できるメーカーのものを購入してください。
VetSheet医薬品リファレンスは獣医専門家の臨床意思決定支援を目的としており、専門的判断または製造業者の最新医薬品情報の代替にはなりません。