From the Guidelines
Lactulose is safe to take daily, with a recommended dose of 10–20 g (15–30 mL or 1–2 packets) daily for constipation, and 20–30 g (25-30 mL) orally 3–4 times per day for hepatic encephalopathy, with adjustments made to achieve 2-3 soft bowel movements per day 1.
Key Considerations
- The dose may be increased to 40 g (60 mL or 2–4 packets) daily if needed for constipation, but it's essential to monitor for side effects such as bloating and flatulence, which are dose-dependent 1.
- For hepatic encephalopathy, the goal is to achieve two to three soft stools per day, and the dose should be titrated accordingly 1.
- It's crucial to stay well-hydrated while taking lactulose and to contact a healthcare provider if severe diarrhea, vomiting, or if symptoms don't improve after several days of treatment occur.
Administration and Side Effects
- Lactulose can be taken with water or juice to improve palatability.
- Common side effects include bloating, flatulence, abdominal cramping, and diarrhea if overdosed.
- In severe cases of hepatic encephalopathy, lactulose may be administered via nasogastric tube or as retention enemas (300 mL lactulose mixed with 700 mL water) when oral administration isn't possible 1.
Important Notes
- Lactulose works by drawing water into the intestine and lowering colonic pH, which reduces constipation and, in hepatic encephalopathy, decreases ammonia production and absorption.
- The use of lactulose in mildly constipated, non-insulin-dependent patients with diabetes mellitus type 2 may not lead to an increase in blood sugar levels 1.
From the FDA Drug Label
The usual adult, oral dosage is 2 to 3 tablespoonfuls (30 mL to 45 mL, containing 20 grams to 30 grams of lactulose) three or four times daily. Continuous long-term therapy is indicated to lessen the severity and prevent the recurrence of portal-systemic encephalopathy. The dose of lactulose for this purpose is the same as the recommended daily dose
The proper dosage and usage of lactulose for treating constipation and hepatic encephalopathy is 2 to 3 tablespoonfuls (30 mL to 45 mL), taken three or four times daily.
- The goal is to produce 2 or 3 soft stools daily.
- Continuous long-term therapy is indicated to prevent the recurrence of portal-systemic encephalopathy, using the same recommended daily dose 2.
From the Research
Lactulose Dosage and Usage
- Lactulose is a synthetic disaccharide used to treat constipation and hepatic encephalopathy due to its efficacy and good safety profile 3.
- The primary site of action is the colon, where lactulose is fermented by colonic bacterial flora, producing short-chain fatty acids and gases 3.
- Lactulose can be administered orally or rectally, and its therapy is considered a first-line treatment for hepatic encephalopathy 4.
Proper Dosage
- The proper dosage of lactulose may vary depending on the condition being treated, but low doses have been shown to be effective as a prebiotic to stimulate the growth of health-promoting bacteria in the gastrointestinal tract 5.
- Low-dose lactulose has been shown to enhance the proliferation of health-promoting gut bacteria, increase the production of beneficial metabolites, and improve mineral absorption 5.
- A low dose of lactulose with food has been shown to delay gastric emptying and increase whole gut transit times, attenuating the hyperglycemic response without adverse gastrointestinal events 6.
Comparison with Other Treatments
- Lactulose has been compared to lactitol in the treatment of chronic hepatic encephalopathy, with meta-analysis showing no statistical difference between therapeutic effects, but a higher frequency of flatulence with lactulose 7.
- Lactulose may have a role as a pharmacotherapeutic agent in the management and prevention of type 2 diabetes via actions on the gut microbiota 6.
- The administration of lactulose enemas instead of or in combination with oral lactulose is common practice in patients with hepatic encephalopathy, and lactulose therapy is considered a first-line treatment 4.