厄貝沙坦
厄貝沙坦是一種**血管張力素II受體拮抗劑 (ARB)**，主要用於人類醫學以控制高血壓和糖尿病腎病變。在獸醫學中，其使用經驗目前非常有限，但可作為 ACE 抑制劑（如依那普利或貝那普利）的替代或輔助藥物，用於治療**伴隨腎功能不全的犬隻高血壓**。 > **臨床要點：** 當病患出現「ACE 逃逸現象」（即儘管使用 ACE 抑制劑，醛固酮濃度仍反彈）或無法耐受 ACE 抑制劑時，常會考慮使用 ARB。與需要肝臟轉化為活性代謝物的氯沙坦 (Losartan) 不同（犬隻對此轉化效率不佳），厄貝沙坦以其原型發揮活性，使其成為犬隻病患更可靠的選擇。 **主要特點：** * 可能對繼發於腎臟疾病的高血壓有用。 * 缺乏用於犬隻心臟衰竭的充分文獻支持。 * 由於具有致畸胎性，**嚴禁於懷孕期間使用**。
作用機制: Irbesartan selectively and competitively blocks the **AT1 (Angiotensin II Type 1) receptor** in the Renin-Angiotensin-Aldosterone System (RAAS). * **Pathway:** Angiotensinogen → Angiotensin I → Angiotensin II. * Angiotensin II normally binds to AT1 receptors to cause potent vasoconstriction and stimulate aldosterone release. * By blocking the AT1 receptor, irbesartan prevents these effects, leading to **vasodilation**, **decreased aldosterone synthesis**, **reduced potassium excretion**, and **increased sodium and water excretion**. * **Pharmacologic Advantage:** It does not inhibit ACE (kininase II), so it does not interfere with bradykinin or substance P responses. Furthermore, it does not require hepatic conversion to an active metabolite, which is a significant pharmacokinetic advantage in dogs compared to losartan.
各物種劑量
- As an alternative to ACE inhibitors for treatment of hypertension associated with renal insufficiency · 5 mg/kg PO q12-24 hours. · PO · q12-24h
劑量為持牌獸醫專業人員的臨床參考。請務必對照最新藥品說明書及個別病患確認。
給藥途徑
禁忌症
- Pregnancy (teratogenic)
- Nursing/lactating animals
- Hypotension
- Uncorrected volume depletion
- Uncorrected sodium depletion
- Hypersensitivity to irbesartan
不良反應
- Diarrhea
- Dyspepsia (indigestion)
- Fatigue or somnolence
- Orthostatic hypotension
- Dizziness
藥物相互作用
- Other antihypertensive agents (e.g., amlodipine, ACE inhibitors) · Increased risk of additive hypotension. Use with caution and monitor blood pressure closely.
- Diuretics · May exacerbate volume depletion and increase the risk of severe hypotension.
監測
- Systemic blood pressure
- Heart rate
- Serum electrolytes (especially potassium)
- BUN and Creatinine (renal function)
- Clinical signs of adverse effects (GI upset, lethargy, weakness)
過量
**Toxicity Profile:** Irbesartan has a wide margin of safety in acute overdose scenarios. Rats and mice have survived acute oral overdoses exceeding 2000 mg/kg. **Clinical Signs of Overdose:** * Severe hypotension * Tachycardia (reflex) or bradycardia **Treatment:** * Treatment is largely **supportive and symptomatic**. * Address hypotension with intravenous fluids and cardiovascular support as needed. * Contact an animal poison control center for specific guidance.
VetSheet 藥物參考供持牌獸醫專業人員作臨床決策輔助之用,不能取代專業判斷或廠方最新藥品說明書。