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クロルテトラサイクリン

Chlortetracycline

テトラサイクリン系抗生物質POIVIMSCTopical (ophthalmic)犬猫小型哺乳類鳥牛豚

別名: Aureomycin · Pennchlor · CTC · CLTC 100 MR · Ophtocycline · clortetraciclina · A-377 · NRRL2209 · SF-66 · Chlortetracycline hydrochloride

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

WHO高位重要抗菌薬 — 責任ある使用を推奨
25 mg/kg PO q6-8hPO· q6-8h
— 🐕

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
Susceptible infections25 mg/kg PO q6-8hPOq6-8h—🌎 NA
Bacterial conjunctivitis, keratitis, blepharitis, and spontaneous chronic corneal epithelial defects (SCCEDs)0.5-2 cm of ointment to affected eyetopicalq6h5 days🌍 EU
  • Bacterial conjunctivitis, keratitis, blepharitis, and spontaneous chronic corneal epithelial defects (SCCEDs): Used for immunomodulatory mechanism in SCCEDs.

猫

適応用量経路頻度期間地域
Susceptible infections25 mg/kg PO q6-8hPOq6-8h—🌎 NA
To prevent recurrence of mycoplasma or chlamydial conjunctivitis in large catteries50 mg per day per catPOq24h1 month🌎 NA
Feline chlamydial conjunctivitis, mycoplasmal conjunctivitis, bacterial keratitis/blepharitis0.5-2 cm of ointment to affected eyetopicalq6h5 days🌍 EU
  • To prevent recurrence of mycoplasma or chlamydial conjunctivitis in large catteries: Administer soluble chlortetracycline powder in food.
  • Feline chlamydial conjunctivitis, mycoplasmal conjunctivitis, bacterial keratitis/blepharitis: Oral doxycycline is the treatment of choice for feline chlamydial conjunctivitis.

小型哺乳類

適応用量経路頻度期間地域
Susceptible infections (Rabbits)50 mg/kg PO q12-24hPOq12-24h—🌎 NA
Susceptible infections (Chinchillas)50 mg/kg PO q12hPOq12h—🌎 NA
Susceptible infections (Hamsters)20 mg/kg IM or SC q12hIM/SCq12h—🌎 NA
Susceptible infections (Mice)25 mg/kg SC or IM q12hSC/IMq12h—🌎 NA
Susceptible infections (Rats)6-10 mg/kg SC or IM q12hSC/IMq12h—🌎 NA

鳥

適応用量経路頻度期間地域
Chlamydiosis (Small birds)0.05% concentration in foodPOContinuous—🌎 NA
Chlamydiosis (Larger psittacines)1% CTC concentration in foodPOContinuous—🌎 NA
Susceptible infections (Ratites)15-20 mg/kg PO three times dailyPOTID—🌎 NA
Susceptible infections (Pigeons)50 mg/kg PO q6-8h; or 1000-1500 mg/gallon drinking waterPOq6-8h or continuous—🌎 NA
  • Susceptible infections (Pigeons): In warm weather mix fresh every 12 hours. Calcium inhibits absorption; withhold grit and layer pellets during treatment.

牛

適応用量経路頻度期間地域
Susceptible infections6-10 mg/kg IV or IM; 10-20 mg/kg POIV/IM/POq24h—🌎 NA
  • Susceptible infections: Generally administered once daily.

豚

適応用量経路頻度期間地域
Susceptible infections6-10 mg/kg IV or IM; 10-20 mg/kg POIV/IM/POq24h—🌎 NA
  • Susceptible infections: Generally administered once daily.

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。

診察中ですか？VetSheet の AI が薬剤・用量・投与期間を構造化された診察記録に直接記入します。VetSheet の仕組みを見る

概要

クロルテトラサイクリンは、広域スペクトルを持つ第一世代の​テトラサイクリン系抗生物質​です。オキシテトラサイクリンやテトラサイクリンとほぼ同じ抗菌スペクトルを持ちますが、獣医療では主に産業動物（牛、豚、家禽）の飼料または飲料水添加物として利用されます。

主な臨床的特徴：

  • ​広域スペクトル：​ 多くのマイコプラズマ、スピロヘータ（ボレリアを含む）、クラミジア、リケッチアに対して有効です。
  • ​耐性菌の増加：​ 多くのグラム陽性菌および陰性菌（大腸菌、クレブシエラ、緑膿菌など）で耐性が進行しています。
  • ​エキゾチックアニマルへの使用：​ 鳥類（特にクラミジア症）や一部の小型哺乳類で頻繁に使用されますが、モルモットには致命的な腸毒素血症を引き起こすため​禁忌​です。

作用機序

Chlortetracycline is a bacteriostatic antibiotic that inhibits bacterial protein synthesis.

  • ​Primary Mechanism:​ Reversibly binds to the 30S ribosomal subunit of susceptible organisms → blocks the binding of aminoacyl transfer-RNA to the mRNA-ribosome complex → halts peptide chain elongation.
  • ​Secondary Mechanism:​ May also reversibly bind to 50S ribosomes and alter cytoplasmic membrane permeability.
  • ​Mammalian effects:​ At very high concentrations, it can inhibit protein synthesis in mammalian cells, leading to antianabolic effects.

安全性・警告

禁忌

  • Known hypersensitivity to chlortetracycline or other tetracyclines
  • Guinea pigs (causes fatal clostridial enterotoxemia)

有害事象

  • Gastrointestinal distress (nausea, vomiting, anorexia, diarrhea)
  • Discoloration of developing teeth and bones (yellow, brown, or gray)
  • Delayed bone growth and healing (at high doses)
  • Hepatotoxicity
  • Increased BUN (antianabolic effect)
  • Ruminal microflora depression and stasis (in ruminants)
  • Intravascular hemolysis and hemoglobinuria (with rapid IV injection of propylene glycol-based products)
  • Colic, fever, and hair loss (in cats)
  • Severe diarrhea (in stressed horses)
  • Superinfections (bacterial or fungal overgrowth)
  • Photosensitivity

注意事項

​Pregnancy Warning:​ Tetracyclines can retard fetal skeletal development and discolor deciduous teeth. Use only in the last half of pregnancy if benefits outweigh risks.

​Organ Impairment:​ Use with caution in patients with renal or hepatic insufficiency. Lower dosages and enhanced monitoring are recommended. Avoid concurrent use of other nephrotoxic or hepatotoxic drugs.

​Laboratory Interactions:​

  • May cause falsely elevated urine catecholamines (fluorometric methods).
  • May cause false-positive urine glucose (cupric sulfate method/Benedict's reagent) or false-negative urine glucose (glucose oxidase method).

​IV Administration:​ Rapid IV injection can induce transient collapse and cardiac arrhythmias due to intravascular calcium chelation. Pre-treatment with IV calcium gluconate may be considered if rapid injection is unavoidable.

医薬品相互作用

Beta-lactam Antibiotics

Bacteriostatic action of tetracyclines may interfere with the bactericidal activity of penicillins and cephalosporins.

Aminoglycosides

May interfere with bactericidal activity.

Digoxin

May increase the bioavailability of digoxin in a small percentage of patients, potentially leading to toxicity.

Divalent or Trivalent Cations (Antacids, Calcium, Iron, Magnesium, Zinc, Bismuth)

Chelation occurs, significantly decreasing the oral absorption of the tetracycline. Separate administration by at least 1-2 hours.

Warfarin

May depress plasma prothrombin activity; anticoagulant dosage may need adjustment.

監視

  • Clinical efficacy (resolution of infection)
  • Gastrointestinal signs (vomiting, diarrhea, anorexia)
  • Renal function (BUN, creatinine) and hepatic function, especially with prolonged use or in compromised patients
  • Fluid and electrolyte status if severe GI distress occurs

過剰投与

Tetracyclines are generally well tolerated after acute overdoses.

  • ​Oral Overdose:​ Most likely associated with gastrointestinal disturbances (vomiting, anorexia, diarrhea). If severe emesis or diarrhea develops, monitor and replace fluids and electrolytes.
  • ​Chronic Overdose:​ May lead to drug accumulation and nephrotoxicity.
  • ​Ruminants:​ High oral doses can cause ruminal microflora depression and ruminoreticular stasis.
  • ​Intravenous Overdose:​ Rapid IV injection of undiluted propylene glycol-based products can cause intravascular hemolysis and hemoglobinuria. Rapid IV injection can also induce transient collapse and cardiac arrhythmias due to chelation with intravascular calcium ions.

製品

製剤

  • Feed additive
  • Water mix preparation
  • Soluble powder

動物用医薬品

  • CTC®
  • CLTC® 100 MR
  • Aureomycin Sulmet® (with sulfamethazine)
  • Aureo S 700® (with sulfamethazine)
  • Aureomix 500® (with sulfamethazine and penicillin)
  • Pennclor SP 250 & 500® (with sulfamethazine and penicillin)
  • Aureozol 500® (with sulfathiazole and penicillin)

規制ステータス

European Union✓ 承認済み処方箋医薬品EMA
🐕 Dogs🐈 Cats

Authorized for treatment of keratitis, conjunctivitis and blepharitis caused by susceptible bacteria.

United Kingdom✓ 承認済み処方箋医薬品VMD
🐕 Dogs🐈 Cats

POM-V classification

規制データなし: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU

保管・安定性

Store in tight containers and protect from light.

飼主向け情報

  • ​投与方法：​ 経口投与の場合、乳製品、制酸剤、鉄分サプリメントと同時に与えないでください。これらは薬と結合して効果を妨げる可能性があります。少なくとも1〜2時間の間隔を空けてください。
  • ​副作用：​ 胃の不調、嘔吐、下痢を引き起こす可能性があります。これらの症状がひどい場合は、獣医師に連絡してください。
  • ​幼若動物：​ 成長期の動物や妊娠中の動物に与えると、歯が永久に黄色や茶色に変色する可能性があります。
  • ​日光：​ ペットの皮膚が日光に対して敏感になる（光線過敏症）可能性があります。治療中は長時間の直射日光を避けてください。
  • ​鳥類：​ 飲料水を通じて鳥を治療する場合、暖かい時期には12時間ごとに新鮮な水に交換してください。カルシウムが薬の吸収を妨げるため、治療中はグリット（小石）や産卵用飼料を与えないでください。

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