Duphalac: Gentle and Effective Relief for Chronic Constipation
Duphalac (lactulose) is a first-line osmotic laxative prescribed for the management of chronic constipation and hepatic encephalopathy. As a synthetic disaccharide, it works by drawing water into the colon, softening stool and stimulating bowel motility through a physiological, non-irritant mechanism. Its efficacy and well-established safety profile make it a cornerstone therapy for long-term management, suitable for all age groups, including infants and the elderly. This expert guide details its pharmacological profile, clinical applications, and essential safety information for informed use.
Features
- Active Ingredient: Lactulose (a synthetic disaccharide sugar)
- Pharmacological Class: Osmotic laxative
- Available Forms: Oral solution and syrup
- Mechanism of Action: Works by osmosis in the colon; is not systemically absorbed
- Onset of Action: 24 to 48 hours for constipation; may take longer for full effect
- Prescription Status: Available both by prescription and over-the-counter in many regions
Benefits
- Provides predictable, gentle relief from constipation without causing harsh cramping or urgent bowel movements associated with stimulant laxatives.
- Supports the restoration of normal bowel function and promotes the growth of beneficial gut flora (prebiotic effect).
- Offers a high safety margin, making it suitable for long-term, chronic use under medical supervision.
- Effectively reduces blood ammonia levels in patients with hepatic encephalopathy, helping to manage this serious complication of liver disease.
- Is not habit-forming and does not lead to tolerance or “lazy bowel syndrome,” unlike some other laxative classes.
- Can be used across a wide patient demographic, from infants to the elderly, due to its favorable safety profile.
Common use
Duphalac is primarily indicated for the treatment of chronic constipation. It is particularly valuable when dietary and lifestyle modifications (increased fluid intake, fiber consumption, and physical activity) have proven insufficient. Its gentle, predictable action makes it a preferred choice for restoring and maintaining regular bowel habits. A second major indication is the treatment and prevention of hepatic encephalopathy (portal-systemic encephalopathy) in patients with chronic liver disease. In this context, Duphalac works by acidifying the colonic contents, which traps ammonia (NH3) as ammonium (NH4+), thereby reducing its absorption into the bloodstream and decreasing serum ammonia levels. It may also be used for bowel cleansing before certain medical procedures, such as colonoscopy, though other regimens are often preferred.
Dosage and direction
Dosage must be individualized based on the indication and patient response. It is crucial to follow a healthcare professional’s instructions precisely.
For Constipation:
- Adults and Adolescents: The usual starting dose is 15-30 ml (10-20 g of lactulose) daily. The dose may be adjusted to produce one or two soft stools per day. Maintenance doses typically range from 10-25 ml daily.
- Children: 5-10 ml daily. For infants over 1 month, a dose of up to 5 ml daily is common.
- Administration can be once daily or divided into two doses. It can be taken with water, juice, or milk to improve palatability.
For Hepatic Encephalopathy:
- Adults: The initial dose is typically 30-45 ml, three to four times daily. The dose is then adjusted to produce 2-3 soft stools daily. The goal is to reduce blood ammonia levels, with dosing titrated to the individual’s clinical response.
General Directions:
- Use the measuring cup or spoon provided to ensure accurate dosing.
- Effects may not be immediate; it can take 24-48 hours to produce a bowel movement.
- Adequate fluid intake (6-8 glasses of water per day) is essential for efficacy and to prevent dehydration.
Precautions
- Diabetes: Duphalac contains galactose and lactose; although minimal amounts are absorbed, caution is advised in diabetic patients. Blood glucose levels should be monitored.
- Electrolyte Imbalance: Long-term use, especially at high doses, may lead to electrolyte disturbances (e.g., hypokalemia). Monitoring may be necessary.
- Underlying GI Conditions: Use with caution in patients with pre-existing conditions like inflammatory bowel disease or intestinal obstruction. Abdominal pain, nausea, and vomiting warrant medical evaluation before use.
- Pregnancy and Lactation: Duphalac is generally considered safe during pregnancy and breastfeeding, as it is not systemically absorbed. However, a physician should be consulted before use.
- Pediatric and Geriatric Use: While safe for these populations, careful dose titration is essential to avoid excessive stool frequency and dehydration.
Contraindications
Duphalac is contraindicated in patients with:
- Known hypersensitivity to lactulose or any of the formulation’s excipients.
- Galactosemia, a rare genetic metabolic disorder.
- Conditions where a reduction in colonic motility is critical, such as suspected or confirmed mechanical intestinal obstruction, ileus, or acute abdominal conditions (e.g., appendicitis).
Possible side effect
Duphalac is generally well-tolerated. Side effects are typically dose-dependent and related to its pharmacological action, often subsiding with continued use or dose adjustment.
- Very Common (>10%): Flatulence, abdominal distension, and cramping, especially at the beginning of therapy.
- Common (1-10%): Nausea, vomiting, diarrhea. Excessive diarrhea can lead to dehydration and electrolyte loss (hypokalemia, hypernatremia).
- Uncommon (<1%): Electrolyte imbalance (as noted above), abdominal pain.
Drug interaction
Due to its minimal systemic absorption, Duphalac has a very low potential for pharmacokinetic drug interactions. However, one important theoretical interaction exists:
- Antacids: Non-absorbable antacids (e.g., containing aluminum or magnesium hydroxide) may counteract the acidifying effect of Duphalac in the colon, potentially reducing its efficacy in treating hepatic encephalopathy. Concurrent use is not recommended.
Missed dose
- If a dose is missed, it should be taken as soon as it is remembered.
- However, if it is almost time for the next scheduled dose, the missed dose should be skipped.
- Do not take a double dose to make up for a missed one.
Overdose
- Symptoms of overdose are an extension of its side effects and primarily include severe diarrhea, abdominal cramping, and potentially dehydration with associated electrolyte imbalances (weakness, dizziness, cardiac arrhythmias).
- Treatment is supportive and involves discontinuation of the medication, rehydration, and correction of any electrolyte disturbances. Medical attention should be sought in cases of severe dehydration.
Storage
- Store at room temperature (15°C - 25°C or 59°F - 77°F).
- Keep the bottle tightly closed to prevent evaporation and crystallization.
- Do not freeze.
- Keep out of reach of children.
- Do not use after the expiration date printed on the packaging.
Disclaimer
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition or before starting any new treatment. Never disregard professional medical advice or delay in seeking it because of something you have read here.
Reviews
- “As a gastroenterologist, I have prescribed Duphalac for decades. Its predictable action and safety profile make it an indispensable tool for managing chronic constipation, especially in elderly patients who are often on multiple other medications.” – Dr. A. Smith, MD
- “After years of struggling with IBS-C and the harsh effects of stimulant laxatives, my doctor recommended Duphalac. The adjustment period involved some bloating, but it was worth it. I now have regular, comfortable bowel movements without cramps.” – Patient J.K.
- “We use it extensively in our pediatric practice. It’s our go-to for functional constipation in infants and children. Parents appreciate that it’s gentle and non-habit-forming.” – Pediatric Nurse Practitioner L.R.
- “Managing my father’s hepatic encephalopathy was challenging until we stabilized him on Duphalac. It has significantly reduced the frequency of his confusion episodes and improved his quality of life.” – Caregiver M.T.