四環黴素
Tetracycline
Tetracycline hydrochloride
別名: Aquadrops · Panmycin · Sumycin · Polyotic · Delta Albaplex · Tetracycline HCl · tetracyclini hydrochloridum
由 VetSheet 獸醫團隊審訂更新於 2026年4月5日本內容以實證獸醫文獻為本
經審核的 v13 劑量證據
結構化劑量計算證據Susceptible infections (extra-label)
- q8-12h
NA
必須一併考量的臨床脈絡 (2)
- ■ This medicine is best given without food. Avoid giving this medicine orally within 1 to 2 hours of milk or other dairy products.
- Unless otherwise instructed by the manufacturer, tetracycline oral tablets and capsules should be stored in tight, light-resistant containers at room temperature (15°C-30°C [59°F-86°F]).
劑量為合格獸醫專業人員的臨床參考。請務必對照最新仿單及個別病患確認。
概覽
四環黴素是一種典型的短效四環黴素類抗生素。雖然過去常作為廣效抗菌藥物使用，但由於細菌抗藥性增加，其臨床角色已發生轉變。
在現代獸醫學中：
- 小動物臨床：對於感染性疾病，通常首選去氧羥四環素 (Doxycycline)，因為其組織穿透力較佳且給藥頻率較低。然而，四環黴素常與菸鹼醯胺 (Niacinamide) 併用，利用其免疫調節作用來治療免疫介導性皮膚病（如盤狀紅斑性狼瘡、天皰瘡）。
- 大動物臨床：通常首選氧四環黴素 (Oxytetracycline)。
臨床要點： 對於非典型病原體如黴漿菌、立克次體、螺旋體（如萊姆病）及披衣菌*仍然有效。
- 具有顯著的抗發炎與免疫調節特性，使其在獸醫皮膚科中具有重要價值。
作用機轉
Tetracycline is a time-dependent, bacteriostatic antibiotic.
- Antimicrobial Action: Reversibly binds to the 30S ribosomal subunit of susceptible organisms → prevents binding of aminoacyl transfer-RNA to the ribosome → inhibits bacterial protein synthesis. It may also bind to the 50S subunit and alter cytoplasmic membrane permeability.
- Immunomodulatory/Anti-inflammatory Action: Suppresses antibody production and neutrophil chemotaxis. Inhibits key inflammatory mediators including lipases, collagenases, prostaglandin synthesis, and the activation of complement component 3.
安全性與警告
禁忌症
- Hypersensitivity to tetracyclines
- Pregnancy (last half) - retards fetal skeletal development and discolors teeth
- Young, growing animals (unless benefits outweigh risks)
不良反應
- Gastrointestinal distress (nausea, vomiting, anorexia, diarrhea)
- Discoloration of developing teeth and bones (yellow/brown/gray)
- Delayed bone growth and healing in young animals
- Superinfections (bacterial or fungal overgrowth)
- Photosensitivity
- Urolith formation (with long-term use in dogs)
- Hepatotoxicity and blood dyscrasias (rare)
- Cats: Colic, fever, hair loss, depression (poorly tolerated)
- Horses: Severe diarrhea (especially if stressed)
- Ruminants: Ruminal microflora depression and stasis (high oral doses)
- Injection site reactions (IM): Local necrosis and yellow staining
注意事項
Extreme Caution: Pregnancy (Category D). Can cause congenital malformations, embryotoxicity, and discoloration of deciduous teeth.
- Renal/Hepatic Impairment: Use cautiously. Lower dosages and enhanced monitoring are recommended. Avoid concurrent nephrotoxic or hepatotoxic drugs.
- Cats: Do not tolerate oral tetracycline well; monitor closely for adverse effects.
- IV Administration: Rapid IV injection can cause transient collapse and cardiac arrhythmias due to calcium chelation. Administer slowly or pre-treat with IV calcium gluconate if rapid injection is necessary.
藥物交互作用
Tetracyclines may decrease atovaquone levels.
Theoretical antagonism of bactericidal activity, though clinical significance is doubtful.
May increase bioavailability of digoxin, potentially causing toxicity that persists for months.
Chelation occurs, significantly decreasing the absorption of tetracycline. Separate doses by at least 1-2 hours.
Concomitant use can cause fatal nephrotoxicity.
May impair oral absorption of tetracycline; separate dosing by at least 2 hours.
May depress plasma prothrombin activity; anticoagulant dosage adjustment may be needed.
監測
- Adverse effects (GI signs, injection site reactions)
- Clinical efficacy
- Periodic renal, hepatic, and hematologic evaluations (with long-term use or in susceptible patients)
藥物動力學
半衰期
吸收
Readily absorbed after oral administration in fasting animals (bioavailability ~60-80%). Food or dairy products can significantly reduce absorption by 50% or more. Erratically and poorly absorbed after IM administration.
分佈
Widely distributed to heart, kidney, lungs, muscle, pleural fluid, bronchial secretions, bile, saliva, urine, synovial fluid, and aqueous/vitreous humor. Poor penetration into CSF. Crosses the placenta and distributes into milk. Volume of distribution is ~1.2-1.3 L/kg in small animals and 1-2.5 L/kg in cattle.
代謝
Apparently not metabolized.
排除
Eliminated unchanged primarily via glomerular filtration. Excreted into the GI tract via biliary and nonbiliary routes (may become inactive after chelation with fecal materials). Patients with impaired renal function can accumulate the drug.
過量
Tetracyclines are generally well tolerated after acute overdoses.
- Oral Overdose: Most likely associated with GI disturbances (vomiting, anorexia, diarrhea). Monitor fluids and electrolytes if severe emesis/diarrhea occurs.
- Chronic Overdose: May lead to drug accumulation and nephrotoxicity.
- Ruminants: High oral doses can cause ruminal microflora depression and ruminoreticular stasis.
- IV Overdose/Rapid Injection: Rapid IV injection can induce transient collapse and cardiac arrhythmias, presumably due to chelation with intravascular calcium ions. If rapid IV administration is necessary, pre-treatment with intravenous calcium gluconate is recommended by some clinicians.
可用產品
劑型
- Capsules
- Oral Suspension
- Soluble Powder (water additive)
- Injection (rarely used in small animals)
獸醫用
- Tetracycline HCl Soluble Powder (water additive): 25 grams/lb or 324 grams/lb
- Delta Albaplex (Combination product containing tetracycline, novobiocin, and prednisone)
人用標示
- Tetracycline HCl Capsules: 250 mg & 500 mg (Sumycin, generic)
- Tetracycline HCl Oral Suspension: 25 mg/mL (Sumycin Syrup)
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儲存與穩定性
Store oral tablets and capsules in tight, light-resistant containers at room temperature (15-30°C). Store oral suspension and powder for injection at room temperature; avoid freezing the oral suspension.
飼主須知
- 給藥方式：盡可能在空腹時給予此藥物。避免在餵食或給予牛奶/乳製品的前後1-2小時內給藥，因為這會顯著降低藥物的吸收。
- 腸胃不適：如果您的寵物出現嘔吐或噁心，可以將藥物與少量非乳製品的食物一起給予，這可能會有所幫助，儘管這可能會稍微降低藥效。
- 陽光照射：此藥物可能會使您寵物的皮膚對陽光更加敏感（光敏性）。請避免長時間暴露在陽光下。
- 牙齒變色：請注意，在生長發育中的幼年動物，此藥物可能會導致牙齒永久性變黃或變棕色。
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