ネオマイシン
Neomycin
Neomycin sulfate
別名: Biosol · Neomix · Neo-325 · Neo-fradin · Neo-Sol 50 · Neovet · Canaural · Soframycin · Neopen · Maxitrol · Nivemycin · fradiomycin sulfate · neomycin sulphate · neomycini sulfas · neomycin B · Framycetin sulphate · Neomycin sulfate · Neomycinum
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
監査済み v13 用量エビデンス
構造化された用量計算エビデンスSusceptible enteric infections (extra-label)
- q6-12h
NA
必ず考慮する臨床コンテキスト (3)
- ■ This medicine may be given by mouth with or without food. If your animal vomits or acts sick after receiving the medicine on an empty stomach, give with food or a small treat to see if this helps.
- Neomycin sulfate oral solution should be stored at room temperature (15°C-30°C [59°F-86°F]) in airtight, light-resistant containers.
- Unless otherwise instructed by the manufacturer, oral tablets/boluses should be stored in airtight containers at room temperature.
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
ネオマイシンは、主にグラム陰性好気性菌に対して有効な広域スペクトルの殺菌性アミノグリコシド系抗生物質です。
全身投与時の腎毒性が他のアミノグリコシド系（ゲンタマイシンやアミカシンなど）よりも著しく高いため、獣医学での使用は主に以下に制限されています：
- 局所投与（皮膚、眼、耳）
- 腸管感染症や手術前の「腸管滅菌」のための経口投与
- 肝性脳症の管理（結腸内のアンモニア産生菌を減少させるため）
臨床のポイント: 全てのアミノグリコシド系と同様に、ネオマイシンは濃度依存性の殺菌作用と有意なポストアンチバイオティックエフェクト（PAE）を示します。しかし、無傷の消化管からの吸収は非常に悪く（わずか約3％）、全身毒性を最小限に抑えながら腸管内で局所的に作用するのに理想的です。
作用機序
Neomycin actively transports across the bacterial cell membrane (an oxygen-dependent process, hence its lack of efficacy against anaerobes). It irreversibly binds to the 30S ribosomal subunit → causes misreading of mRNA → inhibits protein synthesis → leads to rapid bacterial cell death.
安全性・警告
禁忌
- Intestinal obstruction (for oral use)
- Rabbits and hares (disrupts GI flora)
- Neonates (avoid oral use due to higher systemic absorption)
- Animals with a perforated tympanic membrane (eardrum)
- Concurrent use with other known ototoxic products
- Known hypersensitivity to aminoglycosides
- Pre-existing renal disease (for systemic use)
- Ruptured tympanic membrane (for otic preparations)
有害事象
- Nephrotoxicity (severe if given parenterally)
- Ototoxicity (irreversible, parenteral or rarely oral)
- Severe diarrhea
- Intestinal malabsorption
- GI superinfections (with chronic oral use)
- Ototoxicity (deafness)
- Vestibular toxicity (ataxia, head tilt, nystagmus)
- Local irritation or erythema at the application site
- Ototoxicity (vestibular and auditory)
- Severe diarrhoea or malabsorption syndrome (oral use)
- Bacterial or fungal superinfections
- Local irritation (topical ophthalmic use)
注意事項
Use with extreme caution in patients with renal dysfunction, even when given orally, as a small percentage is absorbed. Avoid parenteral use in working dogs due to the risk of irreversible ototoxicity. Use cautiously in patients with neuromuscular disorders (e.g., myasthenia gravis) due to the neuromuscular blocking activity of aminoglycosides. Geriatric and neonatal animals require careful monitoring and dosage adjustments if systemic absorption is expected.
医薬品相互作用
Oral neomycin may decrease digoxin absorption. In a small subset of patients who metabolize digoxin in the GI tract, neomycin may increase serum digoxin levels.
Absorption may be reduced by oral neomycin.
Concurrent use increases the risk of additive toxicity, even with oral neomycin, and should be done with caution.
Concurrent use may cause malabsorption of the penicillin.
Oral neomycin may decrease vitamin K absorption from the gut, potentially increasing anticoagulant effects.
Increased risk of cumulative ototoxicity (deafness and vestibular dysfunction)
Decreased absorption of potassium
Decreased absorption of vitamin K
Synergistic ototoxicity and nephrotoxicity
監視
- Clinical efficacy
- Systemic and GI adverse effects with prolonged use
- Renal function parameters (BUN, creatinine, urinalysis) if used parenterally
- Resolution of clinical signs of otitis
- Integrity of the tympanic membrane (via otoscopy)
- Hearing function and vestibular signs (head tilt, ataxia, nystagmus)
- Renal function (BUN, Creatinine, Urinalysis for casts/protein)
- Hearing and vestibular function (head tilt, nystagmus, ataxia)
- Gastrointestinal signs (diarrhoea)
薬物動態
半減期
吸収
Approximately 3% of a dose is absorbed after oral or rectal administration. Absorption increases if gut motility is slowed or if the bowel wall is damaged. Therapeutic systemic levels are not attained via oral administration.
分布
Distributes to tissues similarly to other aminoglycosides. Does not cross the blood-brain barrier well.
代謝
Not significantly metabolized.
消失
Orally administered neomycin is nearly all excreted unchanged in the feces. Parenterally administered drug is eliminated primarily through renal mechanisms.
過剰投与
Parenteral overdosage carries a high risk of severe nephrotoxicity and ototoxicity. Oral overdosage is less likely to cause systemic toxicity unless the gut wall is compromised, but can lead to severe diarrhea and malabsorption.
製品
製剤
- Oral liquid
- Soluble powder
- Oral tablets
- Topical formulations (ophthalmic, otic, dermatologic)
- Topical: 5 mg/g suspension (often combined with fusidic acid, nystatin, and prednisolone as Canaural)
- Oral: 500 mg tablets
- Parenteral: 100 mg/ml neomycin combined with 200 mg/ml penicillin G
- Topical: 0.25-0.5% dermatological, ophthalmic, and otic preparations
動物用医薬品
- Neomycin Sulfate Oral Liquid: 200 mg/mL
- Neomycin Sulfate Soluble Powder: 325 grams/lb (Neo-325, Neovet 325/100, Neo-Sol 50)
- Canaural Ear Drops (Framycetin 5 mg/g, Fusidic acid 5 mg/g, Nystatin 100,000 IU/g, Prednisolone 2.5 mg/g)
- Neopen (100 mg/ml neomycin + 200 mg/ml penicillin G injection)
ヒト用医薬品
- Neomycin Sulfate Tablets: 500 mg
- Neomycin Sulfate Oral Solution: 25 mg/mL (Neo-fradin)
- Soframycin (Framycetin sulfate 1% topical/ophthalmic preparations - availability varies by region)
- Nivemycin (500 mg tablets)
- Maxitrol (ophthalmic drops/ointment)
規制ステータス
Subject to responsible antimicrobial use guidelines.
規制データなし: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
保管・安定性
Store oral solutions and tablets at room temperature (15-30°C) in tight, light-resistant containers. In the dry state, neomycin is stable for at least 2 years at room temperature.
飼主向け情報
- 経口使用: 下痢を引き起こしたり、正常な腸内細菌叢を変化させる可能性があります。獣医師の指示に注意深く従ってください。
- 毒性の警告: この薬を注射で投与する場合、腎臓の損傷（腎毒性）および難聴/平衡感覚の異常（耳毒性）の重大なリスクがあります。
- ペットが常に新鮮な水を飲めるようにしてください。
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