西沙必利
西沙必利 (Cisapride) 是一種強效的胃腸促動力藥物，在獸醫學中主要用於治療**貓巨結腸症**、**胃排空遲緩**和**反流性食道炎**。 > **臨床要點：** 由於在人類中會引起嚴重的心律不整（QT間期延長），西沙必利已從人類藥品市場自願下架。目前僅能透過**調劑藥局 (compounding pharmacies)** 取得供獸醫病患使用。儘管對人類有心臟風險，但狗和貓通常對其耐受性極佳。 它能有效刺激從食道到結腸的腸胃蠕動，使其成為治療貓慢性便秘的基石療法。
作用機制: Cisapride acts primarily as a **serotonin 5-HT4 receptor agonist** in the gastrointestinal tract. * **5-HT4 activation** → stimulates the release of **acetylcholine** at the myenteric plexus. * This increases lower esophageal sphincter pressure, enhances esophageal peristalsis, and accelerates gastric emptying and colonic motility. * Unlike metoclopramide, it has minimal dopamine receptor blockade (no extrapyramidal effects) and does not stimulate gastric acid secretion. * Acetylcholinesterase activity is not inhibited.
各物種劑量
- For chronic constipation (e.g., megacolon) · 2.5 mg (for cats up to 10 pounds) or 5 mg (for cats 11 pounds or heavier) three times daily, 30 minutes before food. Cats weighing greater than 16 pounds may require 7.5 mg. · PO · q8h · In combination with a stool softener and a bulk agent.
- For chronic constipation (e.g., megacolon) · 1.25-2.5 mg per cat two to three times a day · PO · q8-12h · Cats with hepatic insufficiency should be treated with half the usual dose; probably most effective when given 15 minutes before a meal.
- For chronic constipation (e.g., megacolon) · 2.5-5 mg per cat PO q8-12h · PO · q8-12h
- For chronic constipation (e.g., megacolon) · 5 mg per cat (total dose) PO q8-12h · PO · q8-12h
- For gastric stasis · 0.1 mg/kg PO two to three times daily; cats tolerate 2.5 mg doses without problems · PO · q8-12h
- To reduce the risk for esophageal stricture formation in cases of esophagitis · 0.5-0.75 mg/kg PO three times daily. · PO · q8h
- As a promotility agent (Foals with periparturient asphyxia) · 10 mg (total dose) PO q6-8h. · PO · q6-8h · Adequate time for healing of damaged bowel before using prokinetic agents is essential.
- Promotility (Mice, Rats, Gerbils, Hamsters, Guinea pigs, Chinchillas) · 0.1-0.5 mg/kg PO q12h · PO · q12h
- For ileus if GI tract not obstructed in Guinea pigs, chinchillas · 0.5 mg/kg q8-12h (Route not specified; assume PO) · PO · q8-12h
- GI stasis (Rabbits) · 0.5 mg/kg PO q6-12h. · PO · q6-12h · With IV or SC fluids depending on amount of dehydration, feeding a high fiber slurry and with or without metoclopramide.
- For gastric stasis in rabbits · Usually started at 0.5 mg/kg PO (via NG tube) q8h after first stools were produced or no intestinal obstruction appreciated. · PO · q8h · May be synergistic if used with ranitidine.
- As a promotility agent · 0.1-0.5 mg/kg PO 2-3 times per day given 30 minutes before meals. Higher doses of 1 mg/kg may be required in some cases. · PO · q8-12h · Give 30 minutes before meals.
- To reduce regurgitation associated with megaesophagus · 0.55 mg/kg PO once to three times daily. Practically: 2.5 mg per dose for dogs weighing between 5-10 lbs.; 5 mg per dose for dogs weighing between 11-40 lbs; and 10 mg per dose for dogs greater than 40 lbs. · PO · q8-24h · Administer no closer than 30 minutes before feeding.
- For adjunctive treatment for esophageal reflux · 0.1-0.5 mg/kg PO q8-24h · PO · q8-24h · Use with H-2 blockers or proton pump inhibitors (omeprazole preferred).
- To reduce the risk for esophageal stricture formation in cases of esophagitis · 0.5-0.75 mg/kg PO three times daily. · PO · q8h
- To stimulate detrusor contraction for micturition disorders · 0.5 mg/kg PO q8h · PO · q8h
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
- Gastrointestinal perforation
- Gastrointestinal obstruction
- Gastrointestinal hemorrhage
- Hypersensitivity to cisapride
不良反應
- Vomiting
- Diarrhea
- Abdominal discomfort
- Prolonged QT intervals or cardiac arrhythmias (very rare in veterinary patients)
藥物相互作用
- Anticholinergic agents · May diminish the prokinetic effects of cisapride.
- Benzodiazepines · Cisapride may enhance the sedative effects of benzodiazepines.
- Warfarin · Cisapride may enhance anticoagulant effects; additional monitoring and dosage adjustments may be required.
- Oral drugs with a narrow therapeutic index · Cisapride decreases GI transit times, potentially altering the absorption of other oral drugs. Serum levels may need closer monitoring.
- CYP3A4 Inhibitors (Amiodarone, Ketoconazole, Itraconazole, Fluconazole, Chloramphenicol, Cimetidine, Fluvoxamine, Grapefruit juice, Macrolides except azithromycin) · Inhibit cisapride metabolism, leading to increased cisapride levels and an increased risk for cisapride cardiotoxicity.
- QT-prolonging drugs (Amiodarone, Clarithromycin, Moxifloxacin, Procainamide, Quinidine, Sotalol, Tricyclic Antidepressants) · May increase the risk of QT interval prolongation and fatal arrhythmias when used concurrently with cisapride.
監測
- Efficacy (resolution of GI stasis, constipation, regurgitation)
- Adverse effects profile (GI upset, signs of arrhythmias)
過量
LD50 doses in various lab animals range from 160 - 4000 mg/kg. The reported oral lethal dose in dogs is 640 mg/kg. **Clinical Signs:** Most common adverse effects seen in dogs and cats are diarrhea, lethargy, ataxia, hypersalivation, muscle fasciculations, agitation, abnormal behavior, hyperthermia, and possibly seizures (dogs). **Treatment:** Significant overdoses should be handled using standard gut emptying protocols when appropriate. Supportive therapy should be initiated when required. **Activated charcoal** is effective in binding unabsorbed cisapride.
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。