ペントキシフィリン

Pentoxifylline

1-(5-oxohexyl)-3,7-dimethylxanthine

血液レオロジー改善薬 / 免疫調節薬POIV犬猫馬

別名: Trental · BL-191 · oxpentifylline · pentoxifyllinum · Oxypentifylline

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

体重

Inflammatory/autoimmune dermatologic conditions (extralabel)

8–10 mg/kgPO

q8-12h

必ず考慮する臨床コンテキスト (4)

NOTE: The commercially available pentoxifylline product is a 400 mg extended-release tablet. Cutting or crushing the tablets may negate the extended-release characteristics and alter pharmacokinetics but splitting tablets may be necessary to administer or accurately dose. Avoid crushing tablets for small animal use.
■ Give this medicine with food.
■ Extended-release tablets can be split if necessary to give the appropriate dose. Crushing the tablets may increase the risk for side effects and should be avoided when possible.
The commercially available tablets should be stored in well-closed containers, protected from light at 20°C to 25°C (68°F -77°F).

formularyプロトコル 2023監査 dose-audit-plumb-v13

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。

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概要

ペントキシフィリンは、独自の血液レオロジー改善および免疫調節特性を持つ合成メチルキサンチン誘導体（テオフィリンやカフェインと構造的に関連）です。

犬：主に家族性犬皮膚筋炎、耳介辺縁脂漏症/壊死、皮膚血管炎（アラバマロットなど）といった微小血管障害を伴う免疫介在性皮膚疾患の治療に使用されます。また、アトピー性皮膚炎の補助療法としても使用され、拡張型心筋症（DCM）への応用も研究されています。
馬：皮膚血管炎、エンドトキシン血症、舟状骨病、胎盤炎の補助療法として使用されます。
猫：猫伝染性腹膜炎（FIP）に関連する血管炎を軽減するため、プレドニゾロンと併用されることがあります。

臨床のポイント：組織のリモデリングや炎症に対する効果が現れるまで時間がかかるため、皮膚疾患における臨床的効果が見られるまでに4〜8週間かかる場合があります。

作用機序

The exact mechanisms are multifaceted, combining rheological improvement with anti-inflammatory effects:

Phosphodiesterase (PDE) Inhibition: Inhibits erythrocyte PDE → increases intracellular cAMP → increases erythrocyte flexibility and deformability, allowing red blood cells to navigate compromised microvasculature.
Blood Viscosity Reduction: Reduces plasma fibrinogen and increases fibrinolytic activity.
Immunomodulation: PDE inhibition in leukocytes decreases the production of inflammatory cytokines, notably TNF-α, reducing the negative effects of endotoxemia.
Enzyme Inhibition: In horses, it acts as a potent inhibitor of matrix metalloproteinase-9 (MMP-9) and a modest inhibitor of MMP-2, which may aid in preventing tissue degradation.

安全性・警告

禁忌

Intolerance or hypersensitivity to pentoxifylline or other xanthines (e.g., theophylline, caffeine, theobromine)
Cerebral hemorrhage
Hypersensitivity to methylxanthines (e.g., theophylline, caffeine)
Cerebral or retinal hemorrhage
Severe hepatic or renal impairment (use with caution)

有害事象

Vomiting
Inappetence
Loose stools
Excitement
Nervousness
Dizziness (humans)
Headache (humans)
Erythema multiforme (rare in dogs)
Transient leukocytosis (horses IV)
Muscle fasciculations (horses IV)
Sweating on shoulders/flanks (horses IV)
Mild increases in heart rate (horses IV)
Anorexia
Diarrhea
Restlessness
Tachycardia
Tremors

注意事項

Caution in patients with severe hepatic or renal impairment, or those at risk for hemorrhage.

Pregnancy: FDA Category C. May be teratogenic at high dosages.
Nursing: Excreted in maternal milk. Use cautiously in nursing patients due to potential tumorigenicity seen in rats.

医薬品相互作用

Antihypertensive drugs

May increase hypotensive effect when used concurrently

NSAIDs

Controversial in horses; may negate beneficial effects for endotoxemia, though some studies show superior efficacy when used with flunixin

Platelet-aggregation inhibitors (e.g., aspirin, clopidogrel)

Increased risk for bleeding

TheophyllineMajor

Serum levels of theophylline may be increased when used concurrently

WarfarinModerate

Increased risk of bleeding; use together with enhanced monitoring and caution

CiprofloxacinModerate

May increase pentoxifylline levels

AntihypertensivesMinor

Potential for additive hypotensive effects

監視

Clinical efficacy (resolution of dermatologic or vascular signs)
Adverse effects (GI upset, CNS signs)
Clinical response (resolution of skin lesions/improved blood flow)
Gastrointestinal tolerance
Signs of bleeding

薬物動態

半減期

猫Unknown犬6-7 hours (parent compound), 36 hours (active metabolite 1), 8 hours (active metabolite 5)

吸収

Horses: Rapidly absorbed after PO administration of crushed sustained-release tablets, with wide interpatient variation (bioavailability ~68%). Dogs: Bioavailability is approximately 50% with peak levels occurring 1-3 hours after dosing. Humans: Rapid and almost complete absorption, but undergoes a significant first-pass effect.

分布

Distributive characteristics are not fully described, but it is known that the drug enters maternal milk.

代謝

Metabolized both in the liver and erythrocytes; all identified metabolites appear to be active.

消失

Excreted primarily via urine (inferred from human data).

過剰投与

Signs of overdose in humans include flushing, seizures, hypotension, unconsciousness, agitation, fever, somnolence, GI distress, and ECG changes. One patient who ingested 80 mg/kg recovered completely. Overdoses should be treated using standard methods of appropriate gut emptying (emesis/lavage) and supportive therapies.

製品

製剤

Tablets (sustained-release / controlled-release)
Injection (IV)
400 mg tablet (often modified-release)

ヒト用医薬品

Pentoxifylline Controlled/Extended Release Tablets: 400 mg; Trental® (Hoechst Marion Roussel); generic
Trental 400 mg modified-release tablets

規制ステータス

European Union✓ 承認済み処方箋医薬品EMA

Human POM used off-label under the cascade.

United Kingdom✓ 承認済み処方箋医薬品VMD

Human POM used off-label under the cascade.

規制データなし: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU

保管・安定性

Commercially available tablets should be stored in well-closed containers, protected from light at 15-30°C.

飼主向け情報

投与方法：胃腸の不調（嘔吐や食欲不振）のリスクを大幅に減らすため、この薬は食事と一緒に与えてください。
忍耐が必要です：皮膚や血管の疾患の場合、目に見える改善が現れるまでに数週間（最大6〜8週間）かかることがあります。獣医師の指示がない限り、途中で投薬を中止しないでください。
副作用：嘔吐、下痢、または異常な神経質/興奮が見られないか観察してください。これらの症状が現れた場合は獣医師に連絡してください。
期待されること：この薬に関する獣医療での経験は限られており、リスクとベネフィットのバランスが完全には確立されていないことをご理解ください。

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