乳果糖
Lactulose
4-O-β-D-galactopyranosyl-D-fructose
別名: Cephulac · Constulose · Enulose · Kristalose · Generiac · Duphalac · Lactugal · Laevolac · Lactulosum
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
經審核的 v13 劑量證據
結構化劑量計算證據Constipation (extra-label)
方案 1
須由已驗證獸醫確認
- q6-8h
方案 2
須由已驗證獸醫確認
- q8-12h
NA
必須同時考慮的臨床上下文 (2)
- NOTE: If using the crystals for oral solution: One gram of the crystals is equivalent to 1.5 mL of the liquid.
- Lactulose syrup should be stored protected from light in tight containers, preferably at room temperature (20°C-25°C [68°F-77°F]); avoid freezing. Darkening of the solution may occur, but this does not affect drug potency. Exposure to heat or light may cause extreme darkening or cloudiness; these solutions should be discarded. Lactulose solutions may precipitate; crystals dissolve with gentle reheating.
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。
概覽
乳果糖 (Lactulose) 是一種合成的雙醣類衍生物，由半乳糖和果糖組成。在獸醫學中，它具有兩個主要且高效的作用：
- 肝性腦病 (HE) 管理：它是降低肝功能受損（如門脈系統分流、嚴重肝硬化）病患血氨濃度的基石療法。透過在結腸中捕捉氨，防止神經毒性物質在血液中積聚。
- 滲透性瀉藥：廣泛用於治療慢性便秘和頑固性便秘，特別是患有巨結腸症的貓咪。
臨床小提示：由於貓咪通常非常討厭乳果糖糖漿黏稠、甜膩的口感（這可能導致過度流涎和抗拒），將結晶劑型 (Kristalose) 混入濕食中通常能獲得更好的耐受性，並提高長期的服藥順從性。
作用機制
Lactulose exerts its effects locally in the gastrointestinal tract through two distinct mechanisms:
- Ammonia Reduction (Ion Trapping): Lactulose is not hydrolyzed by mammalian gut enzymes. It reaches the colon intact, where it is fermented by resident bacteria into low-molecular-weight organic acids (lactic, formic, and acetic acids). This fermentation drops the colonic pH. The acidic environment causes diffusible, neurotoxic ammonia (NH3) to migrate from the bloodstream into the colon, where it is protonated into the non-diffusible ammonium ion (NH4+). The ammonium is then trapped in the lumen and excreted in the feces.
- Osmotic Laxative Effect: The unabsorbed disaccharide and its organic acid metabolites exert a strong osmotic pressure, drawing water into the bowel lumen. This increases fecal bulk and moisture, stimulating colonic peristalsis and facilitating bowel movements.
安全性與警告
禁忌症
- Patients requiring a low-galactose diet
- Use with caution in diabetic patients (contains free lactose and galactose)
- Use with caution in patients with preexisting fluid and electrolyte imbalances
- Severely encephalopathic animals at risk of inhalation/aspiration
- Gastrointestinal obstruction
- Animals at risk of gastrointestinal perforation
不良反應
- Flatulence
- Gastric distention
- Abdominal cramping
- Diarrhea (dose-dependent)
- Dehydration (secondary to excessive diarrhea)
- Hypersalivation/aversion in cats (due to taste/texture)
- Diarrhoea
- Dehydration (with excessive dosing)
注意事項
Diabetic Patients: Lactulose syrup contains some free lactose and galactose, which may alter insulin requirements. Electrolyte Imbalances: Lactulose-induced diarrhea can exacerbate preexisting fluid and electrolyte imbalances. Monitor hydration and serum electrolytes during long-term therapy. Feline Administration: The syrup is notoriously difficult to administer to cats due to taste aversion; consider using lactulose crystals mixed with food.
藥物相互作用
Non-adsorbable antacids may reduce the colonic acidification effects and overall efficacy of lactulose.
Should not be used concurrently; loose stools may be falsely attributed to lactulose, resulting in inadequate dosing for hepatic encephalopathy.
Theoretically, oral antibiotics could eliminate the colonic bacteria required to metabolize lactulose, reducing its efficacy. However, clinical synergy is often observed when treating hepatic encephalopathy. Enhanced monitoring is recommended.
Synergy may occur when used together for hepatic encephalopathy.
Lactulose syrup contains free lactose and galactose, which may alter insulin requirements in diabetic patients.
Can be inactivated because lactulose decreases the pH of the colon.
監測
- Clinical efficacy: Aim for 2-3 soft, semi-formed stools per day when used for hepatic encephalopathy or constipation.
- Serum electrolytes (especially during long-term use or in patients with preexisting fluid/electrolyte abnormalities).
- Faecal consistency (aim for 2-3 soft, formed stools per day)
- Blood ammonia levels (in hepatic encephalopathy)
- Hydration status and electrolytes
- Blood glucose levels (in diabetic patients)
藥物動力學
吸收
In humans, less than 3% of an oral dose of lactulose is absorbed in the small intestine.
分佈
Acts locally within the gastrointestinal tract; systemic distribution is minimal.
代謝
The absorbed fraction is not metabolized. The unabsorbed fraction reaching the colon is metabolized by resident bacteria into low molecular weight acids (lactic, formic, acetic) and CO2.
排除
The small absorbed fraction is excreted unchanged in the urine within 24 hours. The unabsorbed, metabolized fraction is excreted in the feces.
過量
Excessive doses of lactulose may cause flatulence, severe diarrhea, abdominal cramping, and dehydration.
Management:
- Reduce the dosage or temporarily discontinue the medication.
- Provide supportive care, including replacement of fluids and electrolytes if dehydration or imbalances occur.
可用產品
劑型
- Oral solution (syrup): 10 g/15 mL
- Crystals for oral solution: 10 g and 20 g packets
- Oral syrup: 3.1-3.7 g/5 ml
- Oral syrup: 10 g/15 ml
人用標示
- Lactulose Solution: 10 grams lactulose per 15 mL (Cephulac, Constulose, Enulose, Generiac)
- Lactulose Crystals for Oral Solution: 10 grams and 20 grams packets (Kristalose)
- Duphalac (syrup)
- Lactugal (syrup)
- Laevolac (syrup)
各地核准狀態
Widely used in veterinary medicine.
Classified as 'P' (Pharmacy medicine) in the UK for human formulations often used off-label in animals.
暫無法規資料: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
儲存與穩定性
Store lactulose syrup in tight containers, preferably at room temperature; avoid freezing. If exposed to heat or light, darkening or cloudiness of the solution may occur, but this does not affect drug potency.
飼主須知
預期效果
- 治療目標：乳果糖治療的理想結果是每天排便 2 到 3 次，呈柔軟成形的狀態（想像成霜淇淋的濃稠度）。
- 劑量調整：您的獸醫師可能會根據寵物糞便的軟硬度，請您稍微調高或調低劑量。
重要警告
- 注意腹瀉：如果您的寵物出現水狀腹瀉，請立即停藥並聯繫您的獸醫師，因為這可能導致危險的脫水。
- 肝臟疾病：如果您的寵物是因為肝病（肝性腦病）服用此藥，且其神經系統症狀惡化（例如：走路不穩、發呆、頭部頂牆）或每天排軟便次數少於 2 次，請立即聯繫您的獸醫師。
貓咪餵藥技巧
- 貓咪通常非常討厭液體糖漿黏稠、甜膩的味道，可能會過度流口水或逃跑。
- 如果您在餵食液體時遇到困難，請向您的獸醫師詢問乳果糖結晶粉 (Kristalose)，它可以輕鬆混入罐頭食品中，貓咪通常更容易接受。
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。