雷尼替丁
Ranitidine
Ranitidine hydrochloride
別名: Zantac 75 · Zantac EFFERdose · AH-19065 · ranitidini hydrochloridum · Ranitidinum
由 VetSheet 獸醫團隊審訂更新於 2026年4月5日本內容以實證獸醫文獻為本
劑量為合格獸醫專業人員的臨床參考。請務必對照最新仿單及個別病患確認。
各物種劑量
🌎 NA — North America🌍 EU — Europe
狗
| 適應症 | 劑量 | 途徑 | 頻次 | 療程 | 地區 |
|---|---|---|---|---|---|
| For esophagitis | 1-2 mg/kg | PO | twice daily | — | 🌎 NA |
| For chronic gastritis | 0.5 mg/kg | PO | twice daily | — | 🌎 NA |
| For ulcer disease | 0.5-2 mg/kg | PO, IV or IM | q8-12h | — | 🌎 NA |
| For ulcer disease | 2 mg/kg | PO, IV | q8h | — | 🌎 NA |
| For ulcer disease (also used for esophagitis) | 1-2 mg/kg | PO, IV, SC | q12h | — | 🌎 NA |
| For ulcer disease | 2 mg/kg | PO, IV | q12h | — | 🌎 NA |
| For gastrinoma | 1-2 mg/kg | PO, SC, IV | q8-12h | — | 🌎 NA |
| For gastrinoma | 0.5 mg/kg | PO, IV or SC | twice daily | — | 🌎 NA |
| To treat hypergastrinemia secondary to chronic renal failure | 1-2 mg/kg | PO | twice daily | — | 🌎 NA |
| To treat hyperhistaminemia secondary to mast cell tumors | 2 mg/kg | PO/IV/IM/SC | q12h | — | 🌎 NA |
| As a prokinetic agent to stimulate gastric contractions | 1-2 mg/kg | PO | q12h | — | 🌎 NA |
| All uses (ulcers, gastritis, prokinetic) | 2 mg/kg | slow IV, SC, PO | q8-12h | Typically 1 month for ulcers (2 weeks post-remission) | 🌍 EU |
- To treat hyperhistaminemia secondary to mast cell tumors: Route not explicitly specified in this line of monograph, typically PO/injectable
- All uses (ulcers, gastritis, prokinetic): Absorption is not clinically significantly affected by food intake.
貓
| 適應症 | 劑量 | 途徑 | 頻次 | 療程 | 地區 |
|---|---|---|---|---|---|
| For ulcer disease/esophagitis | 2.5 mg/kg IV q12h or 3.5 mg/kg PO q12h | IV, PO | q12h | — | 🌎 NA |
| For ulcer disease/esophagitis | 1-2 mg/kg | PO, IV, SC | q12h | — | 🌎 NA |
| For ulcer disease/esophagitis | 2 mg/kg | PO, IV | q12h | — | 🌎 NA |
| As a prokinetic agent to stimulate colonic motility | 1-2 mg/kg | PO | q8-12h | — | 🌎 NA |
| As a prokinetic agent to stimulate colonic motility | 1-2 mg/kg | PO | q12h | — | 🌎 NA |
| All uses | 2 mg/kg/day | IV | constant infusion | — | 🌍 EU |
| All uses | 2.5 mg/kg | IV | Not specified | — | 🌍 EU |
- All uses: Not an effective acid suppressant in healthy cats.
- All uses: Not an effective acid suppressant in healthy cats.
小型哺乳類
| 適應症 | 劑量 | 途徑 | 頻次 | 療程 | 地區 |
|---|---|---|---|---|---|
| As a prokinetic in rabbits | 0.5 mg/kg | IV | q24h | — | 🌎 NA |
| For suspected gastric ulceration in rabbits | 2-5 mg/kg | PO | twice daily | — | 🌎 NA |
- As a prokinetic in rabbits: Used with cisapride (0.5 mg/kg PO q8h).
雪貂
| 適應症 | 劑量 | 途徑 | 頻次 | 療程 | 地區 |
|---|---|---|---|---|---|
| For Helicobacter mustelae | 24 mg/kg | PO | q8-12h | 14 days | 🌎 NA |
- For Helicobacter mustelae: Uses Ranitidine bismuth citrate (must be compounded). Given with clarithromycin (12.5 mg/kg PO q8-12h).
馬
| 適應症 | 劑量 | 途徑 | 頻次 | 療程 | 地區 |
|---|---|---|---|---|---|
| Foals | 1.5 mg/kg IV q8h or 6.6 mg/kg PO q8h | IV, PO | q8h | — | 🌎 NA |
| Foals | 6.6 mg/kg IV q4h or 0.8-2.2 mg/kg IV four times a day; 5-10 mg/kg PO two to four times a day. | IV, PO | q4h or QID (IV); BID-QID (PO) | — | 🌎 NA |
| Adults | 1.5-2 mg/kg IV or IM q6-8h; 6.6 mg/kg PO q8h | IV, IM, PO | q6-8h (IV/IM); q8h (PO) | — | 🌎 NA |
- Foals: Often used with omeprazole (4 mg/kg PO q24h).
劑量為合格獸醫專業人員的臨床參考。請務必對照最新仿單及個別病患確認。
概覽
雷尼替丁 (Ranitidine) 是一種競爭性組織胺H2受體拮抗劑和胃腸促動力藥，廣泛應用於獸醫學。
主要臨床特徵：
- 抑制胃酸： 用於治療和預防胃潰瘍、皺胃潰瘍、十二指腸潰瘍、尿毒症性胃炎，以及壓力或藥物引起的糜爛性胃炎。
- 促胃腸動力： 在H2受體阻斷劑中較為獨特，雷尼替丁能刺激胃腸蠕動，適用於胃排空延遲及促進貓的結腸活動（例如巨結腸症）。
- 全身性肥大細胞增生症： 幫助控制與肥大細胞瘤相關的胃酸分泌過多（肥大細胞瘤會釋放大量組織胺）。
臨床要點： 雷尼替丁的效力（以莫耳濃度計）是西咪替丁 (Cimetidine) 的 3 到 13 倍。此外，由於它不會明顯抑制肝臟細胞色素 P450 酵素，因此藥物交互作用顯著較少，對於同時服用多種藥物的病患來說是更安全的選擇。
作用機轉
Ranitidine exerts its effects via two distinct mechanisms:
- Gastric Acid Suppression: It competitively inhibits histamine at the H2 receptors located on the basolateral membrane of gastric parietal cells.
- Histamine blockade → decreased intracellular cAMP → reduced activation of the H+/K+ ATPase (proton pump) → significant reduction in both basal and stimulated gastric acid and pepsin secretion.
- Prokinetic Effect: It reversibly inhibits acetylcholinesterase (AChE) in the gastrointestinal tract.
- AChE inhibition → decreased breakdown of acetylcholine → increased acetylcholine (ACh) at muscarinic receptors → stimulation of GI smooth muscle motility and increased lower esophageal sphincter pressure.
安全性與警告
禁忌症
- Hypersensitivity to ranitidine
- No specific contraindications available in the monograph
不良反應
- Vomiting (associated with rapid IV boluses in small animals)
- Pain at the injection site (IM administration)
- Mental confusion (rare, documented in humans)
- Headache (rare, documented in humans)
- Agranulocytosis (rare)
- Transient cardiac arrhythmias (if given too rapidly IV)
- Cardiac arrhythmias (rare, typically with rapid IV)
- Hypotension (rare, typically with rapid IV)
注意事項
Use cautiously and consider reduced dosages in patients with diminished renal function or hepatic insufficiency, as the drug may accumulate.
Geriatric patients may be more susceptible to adverse effects.
High-dose, chronic IV therapy (longer than 5 days) has caused increased serum ALT levels in humans; monitoring liver enzymes is recommended in these scenarios.
Use with caution in nursing veterinary patients, as ranitidine is excreted in breast milk (milk:plasma ratio of 5:1 to 12:1).
藥物交互作用
Ranitidine (dose-dependent) may inhibit acetaminophen metabolism.
High doses may decrease the absorption of ranitidine; administer at least 2 hours apart.
Absorption of ketoconazole may be reduced secondary to increased gastric pH.
Absorption of itraconazole may be reduced secondary to increased gastric pH.
Ranitidine may increase metoprolol half-life and peak serum levels.
Ranitidine may increase nifedipine AUC by 30%.
Delays the absorption but increases the peak serum level of ranitidine; relative bioavailability may be increased by 23%.
Long-term ranitidine use may reduce oral absorption of Vitamin B-12.
May affect absorption; advisable to administer sucralfate 2 hours before H2 blockers
Ranitidine may reduce absorption or effect; stagger oral doses by 2 hours
Ranitidine may reduce absorption or effect; stagger oral doses by 2 hours
監測
- Clinical efficacy (resolution of clinical signs, improved appetite, absence of blood in feces/vomitus)
- Endoscopic examination (if indicated for ulcer healing)
- Serum ALT values (consider monitoring during high-dose, chronic IV therapy)
- Resolution of gastrointestinal clinical signs
- Heart rate and blood pressure (during IV administration)
藥物動力學
半衰期
吸收
Dogs: Oral bioavailability is ~81%. Horses: Oral bioavailability is ~27% in adults and 38% in foals. Peak levels occur in 100 mins (adults) and 60 mins (foals). Humans: Rapidly absorbed but undergoes extensive first-pass metabolism (net bioavailability ~50%). Food does not appreciably alter absorption.
分佈
Widely distributed throughout the body. Volume of distribution: 2.6 L/kg (dogs), 1.1 L/kg (adult horses), 1.5 L/kg (foals). Only 10-19% bound to plasma proteins. Distributes into milk at 25-100% of plasma levels.
代謝
Metabolized in the liver to inactive metabolites.
排除
Excreted in the urine by the kidneys via glomerular filtration and tubular secretion. Clearance in horses is ~10 mL/min/kg (adults) and 13.3 mL/min/kg (foals).
過量
Clinical experience with ranitidine overdosage is limited, but the drug has a wide margin of safety.
- Signs of Toxicity: In laboratory animals, massive doses (225 mg/kg/day) have caused muscular tremors, vomiting, and rapid respirations. Single doses of 1 gram/kg in rodents were not fatal.
- Treatment: Handle using standard protocols for oral drug ingestions (e.g., gastric decontamination if recent and appropriate). Treat clinical signs symptomatically and supportively. Hemodialysis and peritoneal dialysis can effectively remove ranitidine from the body.
可用產品
劑型
- Effervescent oral tablets
- Oral solution
- Injection
- Injectable: 25 mg/ml solution
- Oral: 75 mg tablet
- Oral: 150 mg tablet
- Oral: 300 mg tablet
- Oral: 15 mg/ml syrup
獸醫用
- None (No veterinary-labeled products currently available)
人用標示
- Ranitidine HCl Oral Tablets: 75 mg, 150 mg & 300 mg (Zantac, Zantac 75, generic)
- Ranitidine HCl Effervescent Oral Tablets: 25 mg & 150 mg (Zantac EFFERdose)
- Ranitidine HCl Solution: 15 mg/mL (Zantac, generic)
- Ranitidine HCl Injection: 1 mg/mL (premixed) & 25 mg/mL (Zantac, generic)
- Ranitidine 75 mg, 150 mg, 300 mg tablets
- Ranitidine 15 mg/ml syrup
- Ranitidine 25 mg/ml injectable solution
各地核准狀態
POM (Prescription Only Medicine)
POM (Prescription Only Medicine)
暫無法規資料: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
儲存與穩定性
Store tablets in tight, light-resistant containers at room temperature. Store injectable products protected from light at temperatures less than 30°C. A slight darkening of the injectable solution does not affect potency. Injection is stable up to 48 hours when mixed with commonly used IV solutions (including 5% sodium bicarbonate).
飼主須知
雷尼替丁 (Ranitidine) 是一種用於減少胃酸並幫助食物更順暢地通過消化道的藥物。
- 給藥方式： 請務必完全依照獸醫師的指示給藥。請勿漏掉劑量，否則胃酸濃度可能會反彈，導致症狀復發。
- 給藥時間： 可以與食物一起或空腹給予。如果您的寵物同時服用制酸劑（胃藥），請與雷尼替丁間隔至少 2 小時。
- 副作用： 雷尼替丁通常非常安全且耐受性良好。副作用很少見，但可能包括輕微的腸胃不適。
- 保存方式： 請將藥錠保存在密封容器中，置於室溫下並避免陽光直射。
注意： 在給予任何新藥物或保健品之前，請務必諮詢您的獸醫師，儘管雷尼替丁的藥物交互作用比舊款制酸劑（如西咪替丁）來得少。
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