ミコフェノール酸モフェチル
Mycophenolate Mofetil
Mycophenolate mofetil (RS-61443)
別名: CellCept · Cellmune · Imuxgen · Munotras · Mycept · Myfortic · Refrat · RS-61443 · MMF · Mycophenolic acid (active metabolite) · MPA
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
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 |
|---|---|---|---|---|---|
| Immune-mediated hemolytic anemia (IMHA) | 12-17 mg/kg PO once daily or divided twice daily | PO | q12-24h | — | 🌎 NA |
| IMHA, myasthenia gravis or glomerulonephritis | 12-17 mg/kg PO once daily or divided twice daily | PO | q12-24h | — | 🌎 NA |
| Immune-mediated hemolytic anemia (IMHA) | 400-600 mg/m2 orally twice daily | PO | q12h | — | 🌎 NA |
| Adjunctive treatment of glomerulonephritis | 10-20 mg/kg PO q12h | PO | q12h | 3-4 weeks trial | 🌎 NA |
| Pemphigus foliaceous | 22-39 mg/kg/day divided into 3 daily doses | PO | q8h | — | 🌎 NA |
| Pemphigus foliaceous | 20-40 mg/kg/day PO divided q8h | PO | q8h | — | 🌎 NA |
| Aplastic anemia | 10 mg/kg PO q12h | PO | q12h | — | 🌎 NA |
| Rescue agent for generalized myasthenia gravis | 500 mg (15-20 mg/kg) diluted and given IV over 2-4 hours | IV | q24h | 13 days | 🌎 NA |
- Immune-mediated hemolytic anemia (IMHA): Given with prednisolone (at 2 mg/kg q12-24h). Dogs also received ranitidine and sucralfate in the study.
- IMHA, myasthenia gravis or glomerulonephritis: Given with prednisone (at 2.2 mg/kg q12-24h).
- Immune-mediated hemolytic anemia (IMHA): Extrapolated from human medicine. Gastrointestinal side effects are common and dose limiting.
- Adjunctive treatment of glomerulonephritis: Trial of single drug therapy for 3-4 weeks recommended.
- Pemphigus foliaceous: Success rates of approx 50%; most dogs require glucocorticoids to control signs.
- Pemphigus foliaceous: Steroid-sparing only.
- Aplastic anemia: First effects observed 2 weeks later; complete remission in approx 3 weeks.
- Rescue agent for generalized myasthenia gravis: Given daily IV until swallowing oral meds, then switched to 10-11 mg/kg PO q12h.
猫
| 適応 | 用量 | 経路 | 頻度 | 期間 | 地域 |
|---|---|---|---|---|---|
| IMHA | 10 mg/kg PO q12h | PO | q12h | — | 🌎 NA |
- IMHA: Use with caution due to feline glucuronidation deficiency.
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
ミコフェノール酸モフェチル（MMF）は強力な免疫抑制薬であり、獣医療においてステロイド節減薬として、または重度で難治性の免疫介在性疾患のレスキュー療法として利用されることが増えています。
主な臨床応用：
- 免疫介在性溶血性貧血（IMHA）
- 糸球体腎炎
- 重症筋無力症
- 落葉状天疱瘡
- 臓器移植の拒絶反応抑制プロトコル
炎症性腸疾患（IBD）への使用も提案されていますが、犬における主な副作用が消化器症状（胃炎、下痢、腸炎）であるため、使用は複雑です。臨床のポイント： MMFは作用発現が比較的早いため、重篤な症例ではアザチオプリンよりも優先されることがありますが、高価であることと重度の消化器系副作用が制限要因となります。猫での使用経験は非常に限られており、猫はグルクロン酸抱合経路が欠損しているため、極めて慎重に使用する必要があります。
作用機序
Mycophenolate mofetil (MMF) is a prodrug that is rapidly hydrolyzed in vivo to its active form, mycophenolic acid (MPA).
- MPA non-competitively and reversibly inhibits inosine monophosphate dehydrogenase (IMPDH).
- IMPDH is the rate-limiting enzyme in the de novo synthesis of guanosine nucleotides.
- Because T-lymphocytes and B-lymphocytes are highly dependent on this de novo purine synthesis pathway (and lack the purine salvage pathways utilized by other cell types), MPA selectively inhibits their proliferative responses.
- This leads to → suppression of B-cell antibody formation and → inhibition of leukocyte recruitment to inflammatory sites and allotransplant tissues.
安全性・警告
禁忌
- Documented hypersensitivity to mycophenolate
- Pregnancy (teratogenic effects noted in animal models)
- Caution in patients with severe renal dysfunction (dosage adjustment may be required)
- Caution in cats (deficient in glucuronidation metabolism)
- Pre-existing bone marrow suppression
- Pre-existing infections
有害事象
- Diarrhea (can be severe)
- Vomiting
- Anorexia
- Lethargy / reduced activity
- Weight loss
- Lymphopenia
- Increased rates of dermal infections
- Increased susceptibility to systemic infections
- Potential increased risk of malignancy/lymphoma
- Bone marrow suppression
- Nausea
- Diarrhoea
- Increased incidence of infections (e.g., pyoderma, Malassezia)
- Increased risk of lymphoma (reported in humans)
- Headache (reported in humans)
- Hypertension (reported in humans)
- Peripheral oedema (reported in humans)
- Confusion (reported in humans)
- Coughs (reported in humans)
- Tremors (reported in humans)
注意事項
Black Box Warning: In humans, mycophenolate carries a warning regarding a potential increased risk for lymphoma and susceptibility to infections associated with its use.
- Intravenous Administration: Must be administered over at least two hours. Do NOT give as an IV bolus or via rapid IV infusion.
- Feline Patients: The active metabolite (MPA) is primarily excreted as a glucuronide metabolite. Cats are deficient in this metabolic process; use with extreme caution.
- Pregnancy: Teratogenic (increased resorptions and malformations). Avoid use during pregnancy.
- Handling: Due to teratogenic risks, tablets or capsules should not be crushed, split, or opened. Personnel and owners should wear gloves when handling.
医薬品相互作用
Increased serum concentrations of acyclovir and the phenolic glucuronide of mycophenolic acid
Decreased absorption of mycophenolate; separate dosing by at least 2 hours
Potentially increased concentrations of free mycophenolic acid
Increased risk for bone marrow suppression; use together not recommended in humans
Decreased absorption of mycophenolate; separate dosing by at least 2 hours
Potentially increased serum levels of mycophenolic acid and the phenolic glucuronide of mycophenolic acid
May be less effective; avoid use
Competes for secretion, resulting in increased concentrations of either drug
Concomitant administration may decrease the absorption of mycophenolate
監視
- Clinical efficacy (resolution of immune-mediated disease signs)
- Complete Blood Count (CBC) for bone marrow suppression
- Renal and hepatic function panels
- Serum electrolytes
- Gastrointestinal effects (monitor weight, appetite, and client reports of vomiting/diarrhea)
- Complete Blood Count (CBC) to monitor for bone marrow suppression
- Gastrointestinal signs (nausea, vomiting, diarrhea)
- Signs of secondary infections (e.g., skin lesions, lethargy, fever)
薬物動態
半減期
吸収
Absorbed orally but with wide inter-patient and inter-dose variation. Bioavailability in dogs ranges from 54-87%. In humans, oral bioavailability averages 94%, but food reduces peak levels of MPA by up to 40%.
分布
Volume of distribution at steady-state in dogs is approximately 5 L/kg, with wide inter-patient variability (±4.5).
代謝
Rapidly hydrolyzed in vivo to the active form, mycophenolic acid (MPA). MPA is primarily metabolized via glucuronidation (cats are deficient in this pathway).
消失
Primarily excreted in the urine, both unchanged (approx. 5%) and as the glucuronide metabolite (approx. 90%).
過剰投与
In oral acute studies performed in mice and monkeys, no deaths occurred in dosages up to 4,000 mg/kg and 1,000 mg/kg, respectively. In small animals, acute gastrointestinal disturbances (severe vomiting, diarrhea) could be expected. Treatment should be symptomatic and supportive.
製品
製剤
- Oral capsules
- Oral tablets
- Lyophilized powder for injection
- 250 mg capsule
- 500 mg tablet
- 1 g/5 ml powder for oral suspension
- 180 mg tablet
- 360 mg tablet
- 500 mg powder for reconstitution and slow i.v. infusion
ヒト用医薬品
- Mycophenolate Mofetil Oral Capsules: 250 mg (CellCept®)
- Mycophenolate Mofetil Oral Tablets: 500 mg (CellCept®)
- Mycophenolate Mofetil Powder for Oral Suspension: 200 mg/mL (reconstituted) (CellCept®)
- Mycophenolate Mofetil Lyophilized Powder for Injection: 500 mg in 20 mL vials (CellCept®)
- CellCept (250 mg capsule, 500 mg tablet, 1 g/5 ml oral suspension)
- Myfortic (180 mg, 360 mg tablets)
- 500 mg powder for injection
規制ステータス
Human-approved product used off-label in veterinary medicine under the cascade. POM status.
Human-approved product used off-label in veterinary medicine under the cascade. POM status.
規制データなし: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
保管・安定性
Tablets and capsules: Store between 15-30°C and protect from light. Oral suspension: Store powder between 15-30°C. Once reconstituted, store at room temperature or refrigerate (do not freeze); discard unused portion after 60 days. Injectable: Store between 15-30°C. Reconstitute with 5% dextrose. Do not mix with other medications. Administer within 6 hours of dilution.
飼主向け情報
- 投与方法： なるべく空腹時に投与してください。ただし、嘔吐や食欲不振が見られる場合は、食事と一緒に与えて改善するかどうか確認してください。
- 取り扱いの注意： この薬は先天性異常を引き起こす可能性があるため、カプセルや錠剤を砕いたり、割ったり、開けたりしないでください。妊娠中の女性はこの薬の取り扱いを避けてください。投与後は手をよく洗ってください。
- 副作用： 胃腸の不調が最も一般的な副作用です。下痢が続く、重度になる、またはペットが食事をとらなくなった場合は、すぐに獣医師に連絡してください。
- 感染リスク： この薬は免疫系を抑制します。ペットを病気の動物から遠ざけ、感染の兆候（無気力、発熱、新たな皮膚の病変など）に気づいた場合は獣医師に知らせてください。
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