イホスファミド
Ifosfamide
別名: Ifex · Holoxan · Holaxane · Mitoxana · Asoifos · Cuantil · Duvaxan · Fentul · IFO-cell · IFX · Ifocris · Ifolem · Ifomida · Ifosmixan · Ifoxan · Seromida · Troxanol · MJF-9325 · NSC-109724 · Z-4942
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
これは持続点滴（CRI）の速度依存用量です。単純な体重換算ではなく、注入速度を計算してください。
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 |
|---|---|---|---|---|---|
| Lymphomas and soft tissue sarcomas | Give IV saline at 18.3 mL/kg/hr for 6 hours. Give ifosfamide at 350 mg/m2 (if patient weighs less than 10 kg), 375 mg/m2 (if greater than 10 kg) IV during the second 30 minutes of the 6-hour infusion. Mesna at a dose of 20% of the ifosfamide dose is given as an IV bolus at the start of the IV infusion and again 2 and 5 hours after the ifosfamide infusion. Repeat every 3 weeks. | IV | Every 3 weeks | — | 🌎 NA |
| Lymphomas and soft tissue sarcomas | 375 mg/m2 | IV | Every 21 days | — | 🌎 NA |
- Lymphomas and soft tissue sarcomas: Requires saline diuresis and mesna
- Lymphomas and soft tissue sarcomas: Follow cat dose 'b' protocol for diuresis and mesna administration
猫
| 適応 | 用量 | 経路 | 頻度 | 期間 | 地域 |
|---|---|---|---|---|---|
| Vaccine-related sarcomas | 900 mg/m2 every 3 weeks. Mesna bolus and saline diuresis (30 minutes at 18.3 mL/kg/hr) were first given, then ifosfamide and saline diuresis continued for 5 hours after ifosfamide administration completed. | IV | Every 3 weeks | — | 🌎 NA |
| Neoplasia | Normal (0.9%) saline IV diuresis at a fluid rate of 6 times maintenance over 30 minutes. Ifosfamide 900 mg/m2 diluted to 20 mg/mL or less, IV over 20 minutes. Normal saline IV diuresis at 6 times maintenance over 5 hours. Mesna urothelial protectant at 1/5 the patient's calculated mg dose at time zero (immediately before ifosfamide administration), and repeated 2 and 5 hours after ifosfamide. This therapy may be repeated on a 21 day basis. | IV | Every 21 days | — | 🌎 NA |
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
イホスファミドは、シクロホスファミドに構造が類似した強力な抗悪性腫瘍アルキル化剤です。
- プロドラッグ: 薬理活性を示すには肝臓での活性化が必要です。
- 獣医学での用途: 主に犬や猫のリンパ腫や軟部組織肉瘤（猫のワクチン関連肉腫など）の試験的治療プロトコルで使用されます。
- 毒性の警告: 非常に毒性が高く、重篤な出血性膀胱炎や腎毒性を防ぐために、メスナの併用と積極的な生理食塩水による利尿が必須です。
作用機序
Ifosfamide is a cell-cycle phase nonspecific alkylating agent.
- Activation: As a prodrug, it is metabolized primarily by hepatic cytochrome P450 enzymes (and to a lesser extent in the lungs) → ifosfamide mustard (the primary active alkylating metabolite).
- Mechanism: The active mustard metabolite forms covalent bonds with DNA → cross-linking of DNA strands → interferes with DNA replication and RNA transcription → disrupts nucleic acid function and induces cell death.
安全性・警告
禁忌
- Hypersensitivity to ifosfamide
- Severely depressed bone marrow function
- Active hemorrhagic cystitis
有害事象
- Myelosuppression (neutropenia at 5-7 days, potentially delayed to 14-21 days; thrombocytopenia)
- Hemorrhagic cystitis (bladder epithelial damage)
- Nephrotoxicity (proximal and distal tubular damage, electrolyte abnormalities)
- Volume overload and pulmonary edema (secondary to required saline diuresis)
- Neurotoxicity (somnolence, confusion, coma, encephalopathy)
- Gastrointestinal effects (nausea, vomiting, anorexia)
- Hypersensitivity reactions
- Alopecia
- Abnormal liver function tests
注意事項
Because of its toxicity, ifosfamide should only be used by clinicians experienced with cytotoxic agents. Must be used in conjunction with mesna and saline diuresis to reduce the risk of hemorrhagic cystitis and nephrotoxicity. Use with extreme caution in patients with impaired renal function or preexisting cardiac disease (due to volume overload risk). Handle and dispose of as a hazardous cytotoxic drug. FDA Category D for pregnancy (teratogenic and fetotoxic).
医薬品相互作用
May increase concentrations of active ifosfamide and increase toxicity (demonstrated in mice; clinical significance in veterinary patients undetermined)
Ifosfamide may enhance cisplatin-induced ototoxicity and nephrotoxicity
Additive myelosuppression
監視
- CBC with platelets (baseline and before re-dosing)
- Renal function with electrolytes (baseline and before re-dosing)
- Urinalysis (baseline and periodic)
- Liver function (baseline and periodic)
- Other adverse effects (volume overload/pulmonary edema, neurotoxicity, GI toxicity)
- Efficacy
薬物動態
吸収
Well absorbed after SC injection or oral administration (bioavailability >90%), though normally administered IV.
分布
Ifosfamide and its metabolites are widely distributed and enter into both bone and the CNS.
代謝
Prodrug requiring biotransformation. Converted primarily via oxidative pathways in the liver (and to a smaller extent in the lungs) into active metabolites, primarily ifosfamide mustard.
消失
Ifosfamide and its metabolites are primarily excreted via the kidney into urine.
過剰投与
There is limited information available on acute overdoses. Toxicity is expected to be an exacerbation of adverse effects seen at usual doses. No specific antidote (including mesna) is known; treatment is supportive. Methylene blue (50 mg in a ~2% aqueous solution IV over 5 minutes) has been suggested to treat ifosfamide-induced encephalopathy in humans.
製品
製剤
- Powder for IV infusion
ヒト用医薬品
- Ifosfamide Powder for IV infusion: 1 gram with 200 mg amps of Mesnex (mesna) in single dose vials
- Ifosfamide Powder for IV infusion: 3 grams with 400 mg amps of Mesnex (mesna) in single dose vials
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
Store powder at 20-25°C (68-77°F). Protect from temperatures >30°C (86°F) as the drug may liquefy at >35°C (95°F). Reconstituted solution is stable for 24 hours when refrigerated. Compatible with D5W, normal saline, or lactated Ringer's. Compatible and stable when mixed with mesna in D5W or lactated Ringer's.
飼主向け情報
重要な安全上の警告: イホスファミドは強力な抗がん剤であり、重篤な副作用のリスクが高い薬です。多くの場合、試験的な治療として使用されます。
- 取り扱いの注意: この薬はペットの体液に排出されます。治療後少なくとも24時間は、ペットの唾液や尿に直接触れないようにしてください。排泄物を片付ける際は手袋を着用してください。
- 副作用: 感染、出血、嘔吐、または神経系の変化（混乱、極度の眠気など）の兆候がないか注意深く観察してください。
- 入院の必要性: 治療には長時間の静脈内点滴が必要であり、膀胱や腎臓を保護するための追加の水分補給と保護薬の投与が行われます。
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。