フロセミド
Furosemide
4-chloro-2-(furan-2-ylmethylamino)-5-sulfamoylbenzoic acid
別名: Lasix · Salix · Disal · Dimazon · Frusecare · Frusedale · Libeo · Frusol · frusemide · furosemidum · LB-502
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Injection
認証済み獣医師の確認が必要
併用スケジュール条件（すべて適用）
- q12-24h
- q6-8h
NA
必ず考慮する臨床コンテキスト (2)
- NOTE: Watch units closely when calculating doses. Do not confuse CRI dosages using mg/kg/hour with μg/kg/minute.
- Furosemide injection should be stored at room temperature. A precipitate may form if the injection is refrigerated, but it will resolubilize when warmed without alteration in potency. The human injection (10 mg/mL) should not be used if it has a yellow color. The veterinary injection (50 mg/mL) normally has a slight yellow color.
Adjunctive therapy for systemic hypertension
- q8-24h
NA
必ず考慮する臨床コンテキスト (3)
- NOTE: Watch units closely when calculating doses. Do not confuse CRI dosages using mg/kg/hour with μg/kg/minute.
- ■ Furosemide may be given with or without food. If your animal vomits or acts sick after receiving this medicine on an empty stomach, try giving the next dose with food or a small treat. If vomiting continues, contact your veterinarian.
- Store furosemide protected from light at room temperature up to 25°C (77°F). Furosemide tablets should be protected from moisture and stored in light-resistant, well-closed containers. Tablets may discolor with exposure to light, and discolored tablets should be discarded. The oral solution should be stored at room temperature and protected from light and freezing; discard opened bottles after 90 days.
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
フロセミドは強力で即効性のあるループ利尿薬であり、獣医療において体液過剰状態の管理に広く使用されています。多くの動物種において、うっ血性心不全 (CHF) および肺水腫治療の要となります。強力な利尿作用を促すことで、心臓の前負荷を急速に軽減し、静脈うっ血を改善します。
主な心疾患への応用に加え、フロセミドは以下の目的でも使用されます：
- 乏尿性腎不全： 乏尿を多尿に転換し、尿量を確保するため。
- 高カルシウム血症： 腎臓からのカルシウム排泄を促進するため（事前の輸液による細胞外液補充が必要）。
- 運動誘発性肺出血 (EIPH)： 競走馬において鼻出血を軽減するための予防的使用。
- 乳房浮腫： 牛の分娩後における使用（FDA承認）。
その強力な作用のため、フロセミドは著しい体液および電解質の変動を引き起こす可能性があり、水分状態や血清電解質（特にカリウム）の慎重なモニタリングが必要です。
作用機序
Furosemide acts primarily on the thick ascending limb of the loop of Henle in the nephron.
- Inhibition of NKCC2: It reversibly binds to and inhibits the Na⁺/K⁺/2Cl⁻ cotransporter on the luminal membrane → prevents the reabsorption of sodium, potassium, and chloride.
- Loss of Medullary Hypertonicity: This disruption abolishes the hypertonic medullary interstitium → impairs the kidney's ability to concentrate urine → results in profound, dose-dependent diuresis.
- Electrolyte Excretion: It significantly increases the renal excretion of water, Na⁺, K⁺, Cl⁻, Ca²⁺, Mg²⁺, H⁺, NH₄⁺, and bicarbonate.
- Hemodynamic Effects: Furosemide induces mild renal venodilation and transiently increases glomerular filtration rate (GFR) via prostaglandin release. This venodilation provides rapid relief in acute cardiogenic pulmonary edema, often before the onset of significant diuresis.
安全性・警告
禁忌
- Anuria
- Hypersensitivity to furosemide
- Progressive renal disease if increasing azotemia and oliguria occur during therapy
- Seriously depleted electrolytes
- Severe dehydration
- Severe electrolyte depletion
- Hepatic coma
- Pericardial effusion where cardiac tamponade is confirmed
有害事象
- Fluid and electrolyte abnormalities (hyponatremia, hypokalemia, hypocalcemia, hypomagnesemia)
- Prerenal azotemia (secondary to dehydration)
- Ototoxicity (especially in cats with high-dose IV therapy)
- Gastrointestinal distress
- Hematologic effects (anemia, leukopenia)
- Weakness and restlessness
- Hypokalaemia
- Hypochloraemia
- Hypocalcaemia
- Hypomagnesaemia
- Hyponatraemia
- Polyuria/polydipsia (PU/PD)
- Prerenal azotaemia
- Gastrointestinal disturbances
- Leucopenia
- Anaemia
- Electrolyte depletion (hypokalemia, hyponatremia, hypochloremia)
- Polyuria and polydipsia
注意事項
Use with caution in patients with pre-existing electrolyte or water balance abnormalities, impaired hepatic function (may precipitate hepatic coma), and diabetes mellitus. Monitor carefully in patients with conditions leading to fluid loss (e.g., vomiting, diarrhea). Patients hypersensitive to sulfonamides may also be hypersensitive to furosemide. Ensure animals have normal food and water intake to prevent imbalances.
医薬品相互作用
Increased risks for hypotension, particularly in patients who are volume or sodium depleted secondary to diuretics
Increased risk for ototoxicity
Loop diuretics may increase the risk for nephrotoxicity development; hypokalemia
Increased risk for GI ulceration; hypokalemia
Furosemide-induced hypokalemia may increase the potential for digoxin toxicity
Furosemide may alter insulin requirements
Furosemide may prolong neuromuscular blockade
Furosemide can reduce uricosuric effects
Loop diuretics can reduce the excretion of salicylates
Furosemide may potentiate effects
Pharmacologic effects of theophylline may be enhanced when used with furosemide
Potentiates nephrotoxicity and ototoxicity
Increased risk of hypokalaemia
Increased risk of hypokalaemia
Decreased diuretic efficacy and predisposes to nephrotoxicity, particularly with poor renal perfusion
Inhibits muscle relaxation qualities
Increases the effects of suxamethonium
Increased risk of hypotension and renal impairment; however, concurrent use is standard of care for heart failure with appropriate monitoring.
Increased risk of ototoxicity and nephrotoxicity.
監視
- Serum electrolytes (especially potassium, sodium, calcium, magnesium)
- Blood glucose
- Hydration status
- Blood pressure, if indicated
- Clinical signs of edema, patient weight, if indicated
- Evaluation of ototoxicity, particularly with prolonged therapy or in cats
- Resting respiratory rate (at home by owner)
- Serum electrolytes (Potassium, Sodium, Chloride, Calcium, Magnesium)
- Renal parameters (BUN, Creatinine)
- Clinical signs of ototoxicity (especially in cats)
- Serum electrolytes (especially Potassium, Sodium, Chloride)
- Renal function (BUN, Creatinine)
- Clinical signs of edema/heart failure resolution
薬物動態
半減期
吸収
In dogs, oral bioavailability is approximately 77%. In humans, 60-75% absorbed following oral administration. Diuretic effect takes place within 5 minutes after IV administration and within 1 hour after oral dosing. Peak effects occur ~30 minutes after IV and 1-2 hours after PO.
分布
Approximately 95% bound to plasma proteins in both azotemic and normal patients.
代謝
Undergoes some hepatic metabolism (glucuronidation).
消失
Excreted primarily via the kidneys.
過剰投与
The LD50 in dogs after oral administration is >1000 mg/kg; after IV injection >300 mg/kg. Chronic overdosing at 10 mg/kg for six months in dogs led to development of calcification and scarring of the renal parenchyma.
Acute overdosage may cause severe electrolyte and water balance problems, CNS effects (ranging from lethargy to coma and seizures), and cardiovascular collapse.
Treatment:
- Empty the gut after recent oral ingestion using standard protocols.
- Avoid concomitant cathartics as they may exacerbate fluid and electrolyte imbalances.
- Aggressively monitor and treat electrolyte and water balance abnormalities supportively.
- Monitor respiratory, CNS, and cardiovascular status.
製品
製剤
- Oral Solution (Syrup)
- Injection
- Oral tablets
- Injectable solution (IV/IM/SC)
- Injectable: 50 mg/ml solution
- Oral: 10 mg tablet
- Oral: 20 mg tablet
- Oral: 40 mg tablet
- Oral: 20 mg/5 ml sugar-free solution
- Oral: 40 mg/5 ml sugar-free solution
- Oral: 50 mg/5 ml sugar-free solution
動物用医薬品
- Furosemide Tablets: 12.5 mg, & 50 mg; Salix, Disal, generic
- Furosemide Oral Solution (Syrup): 10 mg/mL in 60 mL; generic
- Furosemide for Injection: 50 mg/mL (5%) in 50 mL & 100 mL vials; Disal Injection, Salix Injection, generic
- Dimazon 10 mg, 50 mg tablets
- Dimazon 5% injectable solution
- Frusecare 40 mg tablets
- Frusedale 40 mg tablets
- Libeo 10 mg, 40 mg chewable tablets
ヒト用医薬品
- Furosemide Oral Tablets: 20 mg, 40 mg, & 80 mg; Lasix; generic
- Furosemide Oral Solution: 10 mg/mL in 60 mL & 120 mL; 40 mg/5 mL in 500 mL & UD 5 mL & 10 mL; generic
- Furosemide Injection: 10 mg/mL in 2 mL (20 mg), 4 mL (40 mg) & 10 mL (100 mg) single-dose vials; generic
- Lasix 20 mg, 40 mg tablets
- Lasix oral solution
- Lasix injectable solution
- Frusol
規制ステータス
POM-V classification in the UK.
POM-V, POM.
規制データなし: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
保管・安定性
Tablets should be stored in light-resistant, well-closed containers. Oral solution should be stored at room temperature and protected from light and freezing. Injection should be stored at room temperature. A precipitate may form if the injection is refrigerated, but will resolubilize when warmed without alteration in potency. Unstable at an acid pH, but very stable under alkaline conditions.
飼主向け情報
フロセミド（商品名ラシックスとしてよく知られています）は、ペットの体内の余分な水分を排出するのを助ける強力な利尿薬です。心不全や肺に水が溜まる症状に対して最もよく処方されます。
重要： この薬は体から水分を取り除くため、ペットの排尿回数と尿量が大幅に増えます。重度の脱水症状を防ぐため、常に新鮮な水を自由に飲めるようにしておいてください。
- 自宅でのモニタリング： ペットが心疾患の治療を受けている場合、獣医師からペットの安静時呼吸数（睡眠中の1分間の呼吸数）を数えるよう指示されることがあります。これは薬の用量が適切かどうかを確認するための重要な指標です。
- 獣医師に連絡するタイミング： 異常な喉の渇き、極度の無気力、脱力感、落ち着きのなさ、尿量の減少、嘔吐、心拍数の異常な増加など、脱水や電解質異常の兆候に気づいた場合は、すぐに獣医師に連絡してください。
- 投薬について： 獣医師の指示通りに正確に投薬してください。水分を取り除くことと脱水を引き起こすことのバランスは非常にデリケートであるため、獣医師に相談せずに用量を変更しないでください。
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。