トリメトプリム/スルファジアジン および トリメトプリム/スルファメトキサゾール
Sulfadiazine/Trimethoprim and Sulfamethoxazole/Trimethoprim
Trimethoprim/Sulfadiazine, Trimethoprim/Sulfamethoxazole
別名: Co-trimoxazole · Tribrissen · Bactrim · Septra · Tucoprim · Uniprim · Di-Biotic · Cotrim · Sulfatrim · Trivetrin · Borgal · SMX-TMP · trimethoprim-sulfamethoxazole · sulfadiazine-trimethoprim · TMP-SDZ · Co-trimazine
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Coccidiosis
- q12-24h
NA
必ず考慮する臨床コンテキスト (3)
- NOTE: There is significant controversy regarding the frequency of administration of these drugs. See Pharmacokinetics for more information. Unless otherwise noted, doses are for combined sulfa-/trimethoprim. See Monitoring if treatment is expected to be longer than 7 days.
- Bacterial cystitis (extra-label): Potentiated sulfonamides (ie, sulfa-/ trimethoprim, sulfadimethoxine/ormetoprim) are first-tier drugs only if regional pathogen susceptibility patterns are known. 32
- Unless otherwise instructed by the manufacturer, sulfa-/trimethoprim products should be stored at room temperature of 20°C to 25°C (68°F-77°F) in tight containers and protected from freezing. Shake suspensions well before use.
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
強化サルファ剤（TMS、SMZ-TMP、またはコトリモキサゾールとよく呼ばれる）は、獣医療で広く使用されている広域スペクトルの殺菌性抗菌薬の配合剤です。
重要な臨床的ポイント：
- 優れた組織移行性： 脂溶性が高く、前立腺、血液脳関門（CNS）、眼などの到達しにくい組織でも治療濃度に達します。
- 広域スペクトル： メチシリン耐性ブドウ球菌（MRSA/MRSP）の多くの株、ノカルジア、および特定の原虫（トキソプラズマ、コクシジウム、ニューモシスチス）を含む、多くのグラム陽性および陰性菌に有効です。
- 膿による不活化： 薬効は化膿性デブリや壊死組織（PABAとチミジンが豊富）によって著しく阻害されます。効果を得るためには膿瘍の排膿が必要です。
- 犬種の感受性： ドーベルマン・ピンシャーは、サルファ剤誘発性の多系統免疫複合体疾患（過敏症）に対する犬種特異的な感受性があることが知られています。
- 剤形： 獣医承認のトリメトプリム/スルファジアジン製品が存在しますが、多くの獣医師はヒト用承認のトリメトプリム/スルファメトキサゾール（Bactrim®、Septra®）を適応外使用し、同様の有効性を得ています。
作用機序
Potentiated sulfas exhibit synergistic, bactericidal activity by sequentially blocking the bacterial folic acid synthesis pathway. Mammalian cells are largely unaffected because they utilize preformed dietary folate rather than synthesizing it.
- Sulfonamides (Bacteriostatic alone): Act as structural analogues of para-aminobenzoic acid (PABA). They competitively inhibit the bacterial enzyme dihydropteroate synthase → blocks the conversion of PABA to dihydrofolic acid (DFA).
- Trimethoprim (Bactericidal alone): Reversibly inhibits the bacterial enzyme dihydrofolate reductase → blocks the conversion of DFA to tetrahydrofolic acid (THFA).
- Synergy: The sequential blockade completely depletes THFA, an essential cofactor for bacterial DNA and RNA synthesis, leading to rapid bacterial cell death.
Pharmacologic Note: The optimal in vitro ratio for most susceptible bacteria is 1:20 (trimethoprim:sulfa), but synergistic activity occurs across a wide range (1:1 to 1:40). The serum concentration of the trimethoprim component is generally considered the primary driver of efficacy.
安全性・警告
禁忌
- Hypersensitivity to sulfonamides, thiazides, or sulfonylurea agents
- Severe renal or hepatic impairment
- Doberman pinschers (highly susceptible to immune complex disease)
- Marked blood dyscrasias
- Animals intended for food (in the USA/certain jurisdictions)
有害事象
- Dogs: Keratoconjunctivitis sicca (KCS/dry eye - potentially irreversible)
- Dogs: Hypersensitivity reactions (Type 1 anaphylaxis or Type 3 serum sickness, polyarthritis, urticaria, facial swelling)
- Dogs: Acute neutrophilic hepatitis with icterus, idiosyncratic hepatic necrosis
- Dogs: Vomiting, anorexia, diarrhea
- Dogs: Hemolytic anemia, agranulocytosis
- Dogs: Hypothyroidism (with extended therapy)
- Dogs: Crystalluria, hematuria, polyuria, polydipsia
- Cats: Anorexia, crystalluria, hematuria, leukopenias, anemias
- Horses: Transient pruritus (after IV injection), diarrhea, hypersensitivity, hematologic effects
- Injection site reactions: Swelling, pain, tissue damage (IM, SC, or extravasation)
注意事項
Use with caution in patients with pre-existing hepatic or renal disease. Because of its potential for crystallization in the urine, avoid use in dogs known to have uroliths, at increased risk for developing uroliths, or those with highly concentrated (dehydrated) or acidic urine. Potentially teratogenic (cleft palate reported); weigh risk vs. benefit in pregnant animals. Use with caution in nursing animals as sulfonamides are excreted in milk and may cause kernicterus in neonates.
医薬品相互作用
May cause toxic delirium (reported in humans)
May decrease the bioavailability of sulfonamides if administered concurrently
May increase the risk of nephrotoxicity
May increase digoxin levels
May increase risk for thrombocytopenia
May potentiate hypoglycemic effects
May displace from plasma proteins and increase risk for toxic effects; can also interfere with MTX assays
May increase half-life of phenytoin
May decrease efficacy of the antidepressant
May prolong INR/PT and increase bleeding risk
監視
- Clinical efficacy
- Adverse effects (GI, hypersensitivity)
- Complete blood counts (CBC) periodically with chronic therapy
- Schirmer Tear Test (STT) in dogs to monitor tear production (e.g., at 5 days, then every 2-3 weeks)
- Thyroid function tests (baseline and ongoing) for dogs on long-term treatment
薬物動態
半減期
吸収
Well absorbed after oral administration, with peak levels occurring about 1-4 hours after dosing. More slowly absorbed after subcutaneous administration. In ruminants >8 weeks old, trimethoprim is trapped in the ruminoreticulum after oral administration and undergoes degradation.
分布
Well distributed in the body. Enters CSF at about 50% of serum levels when meninges are inflamed. Crosses the placenta and distributes into milk. Relatively well distributed into the prostate. Volume of distribution for trimethoprim: 1.49 L/kg (dogs), 0.59-1.51 L/kg (horses). Vd for sulfadiazine in dogs is 1.02 L/kg.
代謝
Metabolized by the liver. Sulfas are primarily acetylated and conjugated with glucuronic acid. Trimethoprim is metabolized to oxide and hydroxylated metabolites. Trimethoprim may be more extensively metabolized in the liver in adult ruminants.
消失
Renally excreted unchanged via glomerular filtration and tubular secretion, as well as hepatic metabolism. Trimethoprim is rapidly eliminated from serum but may persist longer in tissues.
過剰投与
Manifestations of acute overdosage include GI distress (nausea, vomiting, diarrhea), CNS toxicity (depression, headache, confusion), facial swelling, bone marrow depression, and elevated serum aminotransferases.
Treatment:
- Oral Overdose: Empty the stomach following usual protocols and initiate symptomatic/supportive therapy.
- Fluid Therapy: Maintain hydration. Acidification of urine may increase renal elimination of trimethoprim but increases the risk of sulfonamide crystalluria (especially with sulfadiazine).
- Monitoring: Monitor complete blood counts and liver parameters.
- Bone Marrow Suppression: If severe and associated with chronic overdose, may be treated with folinic acid (leucovorin).
- Note: Peritoneal dialysis is not effective in removing TMP or sulfas from circulation.
製品
製剤
- Oral Paste
- Sterile Injection
- Oral Powder
- Oral Tablets
- Oral Suspension
動物用医薬品
- Trimethoprim/Sulfadiazine Oral Paste: 67 mg TMP / 333 mg SDZ per gram (Tribrissen 400 Oral Paste)
- Trimethoprim/Sulfadiazine Sterile Injection: 48% (Di-Biotic 48%, Tribrissen 48% Injection)
- Trimethoprim/Sulfadiazine Powder: 67 mg TMP / 333 mg SDZ per gram (Tucoprim, Uniprim)
- Trimethoprim/Sulfadoxine (Canada): Trivetrin, Borgal
ヒト用医薬品
- Trimethoprim Tablets: 100 mg, 200 mg (Proloprim, Trimpex)
- Trimethoprim/Sulfamethoxazole (TMP-SMZ) Tablets: 80 mg TMP / 400 mg SMX (Bactrim, Septra)
- Trimethoprim/Sulfamethoxazole Double Strength (DS) Tablets: 160 mg TMP / 800 mg SMX (Bactrim DS, Septra DS)
- Trimethoprim/Sulfamethoxazole Oral Suspension: 8 mg TMP / 40 mg SMX per mL (Septra, Cotrim Pediatric, Sulfatrim)
- Trimethoprim/Sulfamethoxazole Injection: 16 mg TMP / 80 mg SMX per mL
規制ステータス
規制データなし: 🇺🇸 US · 🇪🇺 EU · 🇬🇧 UK · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
保管・安定性
Unless otherwise instructed by the manufacturer, trimethoprim/sulfadiazine and co-trimoxazole products should be stored at room temperature (15-30°C) in tight containers.
飼主向け情報
飼い主様への重要なご案内：
- 水分補給が重要です： この薬を服用している間は、ペットが常に新鮮な水を十分に飲めるようにしてください。脱水状態になると、腎臓や尿中に薬の結晶ができる可能性があります。
- 目の状態に注意（犬）： この薬は涙の分泌を減少させ、「ドライアイ」（乾性角結膜炎）を引き起こす可能性があります。犬が目を細めたり、目をこすったり、充血、またはドロドロした黄緑色の目やにが出ているのに気づいたら、すぐに獣医師に連絡してください。
- アレルギー反応： ドーベルマン・ピンシャーや一部の大型犬はアレルギー反応を起こしやすい傾向があります。顔の腫れ、じんましん、原因不明の発熱、関節のこわばり/足を引きずる、または目や歯茎の黄疸に気づいた場合は、薬を中止し獣医師に連絡してください。
- 投薬方法： 食事と一緒でも、食事なしでも与えることができます。液体の懸濁液を使用する場合は、毎回用量を吸い上げる前によく振ってください。液体の冷蔵保存は不要です。
- 最後まで飲み切る： ペットが完全に良くなったように見えても、抗生物質耐性を防ぐため、必ず獣医師の指示通りに処方された分を最後まで飲み切ってください。
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。