尼扎替丁
尼扎替丁（Nizatidine）是一種**H2受體拮抗劑**，其結構和藥理作用與雷尼替丁（ranitidine）相似。雖然它具有抑制胃酸的能力，但在獸醫學（特別是小動物臨床）中，主要利用其**促胃腸動力**的特性。 * 用於治療胃排空延遲、腸道假性阻塞以及貓便秘/巨結腸症。 * 可能有助於預防貓胰臟炎中的出血性壞死。 > **臨床要點：** 由於目前有更強效的抑酸劑（如質子幫浦抑制劑）和其他促動力藥物，尼扎替丁在臨床上較少使用，但當需要同時具備抑酸和促動力雙重作用時，它仍是一個可行的選擇。
作用機制: * **Acid Suppression:** Competitively inhibits histamine at the **H2 receptors** on gastric parietal cells → reduces basal and stimulated gastric acid output → decreases pepsin secretion. * **Prokinetic Action:** Inhibits **acetylcholinesterase** → prevents breakdown of acetylcholine → increases acetylcholine concentrations at **muscarinic receptors** → stimulates GI motility. * May also exert direct agonist effects on **M3 muscarinic receptors**. * Increases lower esophageal sphincter (LES) pressure.
各物種劑量
- As a colonic prokinetic agent · 2.5-5 mg/kg PO once daily · PO · once daily
- As a colonic prokinetic agent (in combination with cisapride) · 2.5-5 mg/kg PO q12h · PO · q12h · Used in combination with cisapride
- As a prokinetic agent · 2.5-5 mg/kg PO once daily · PO · once daily
- As an H2 blocker to reduce gastric acid production · 5 mg/kg PO once daily · PO · once daily · Dosage not well established
劑量為合格獸醫專業人員的臨床參考。請務必對照最新藥品仿單及個別病患確認。
給藥途徑
禁忌症
- Hypersensitivity to nizatidine
不良反應
- Anemia (rare)
- Headache/dizziness (rare)
- Rash/pruritus (rare)
- Cholinergic effects at high doses
藥物相互作用
- Anticholinergic agents (atropine, propantheline) · May negate the prokinetic effects of nizatidine
- Aspirin (and other salicylates) · May increase salicylate levels in patients receiving high doses of aspirin
監測
- Clinical efficacy (decrease in symptoms, endoscopic examination, blood in feces)
- Serum ALT values (in high dose, chronic therapy)
過量
Single oral doses up to 800 mg/kg were not lethal in dogs. Overdose may cause cholinergic effects (lacrimation, salivation, emesis, miosis, diarrhea). Treat supportively and symptomatically.
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。