Levolac (Lactulose)

Levolac (lactulose) acts as an osmotic laxative and ammonia‑lowering agent in the gastrointestinal tract.

• Constipation: softens stool and promotes bowel movements, relieving chronic constipation.
• Hepatic encephalopathy: lowers intestinal ammonia production, helping improve mental status in patients with liver disease.
• Prevention of hepatic encephalopathy recurrence: maintains low ammonia levels to reduce the risk of future episodes.

• Lactulose is a synthetic disaccharide that is not absorbed in the small intestine. In the colon, bacterial enzymes hydrolyze it to short‑chain fatty acids, which increase osmotic pressure and draw water into the lumen. The resulting acidification of colonic contents converts ammonia (NH₃) to ammonium (NH₄⁺), trapping it in the gut and decreasing systemic absorption. This process also promotes a favorable shift in gut microbiota that further supports ammonia reduction.

Lactulose may cause several adverse reactions, ranging from mild gastrointestinal discomfort to rare serious events.

Common Side Effects

• Bloating: sensation of abdominal fullness.
• Diarrhea: loose stools, especially at higher doses.
• Nausea: feeling of sickness.

Serious or Rare Side Effects

• Severe dehydration: excessive fluid loss requiring medical attention.
• Electrolyte imbalance: abnormal potassium or sodium levels.
• Allergic reaction: rash, itching, or swelling.

When prescribing lactulose, clinicians should consider several safety measures to minimize risks.

• Dose adjustment in renal impairment: monitor for accumulation and adjust as needed.
• Monitor electrolytes: especially potassium and sodium during prolonged therapy.
• Caution in diabetic patients: lactulose contains carbohydrate that may affect blood glucose.
• Avoid abrupt discontinuation: sudden stop can lead to rebound constipation.
• Pregnancy safety unknown: use only if potential benefit justifies risk.
• Store at room temperature: keep in original container, protect from moisture and heat.

Lactulose can interact with other medicines, altering efficacy or safety.

Major Interactions (Avoid)

• Antibiotics (e.g., rifaximin): may reduce lactulose’s ammonia‑lowering effect.
• Other laxatives: additive effect can cause severe diarrhea and dehydration.
• Insulin or oral hypoglycemics: carbohydrate content may require dose adjustment.

Moderate Interactions (Monitor Closely)

• Diuretics: monitor electrolyte status due to potential additive fluid loss.
• Mineral supplements (e.g., calcium, magnesium): may affect absorption of lactulose.
• Probiotics: may modify gut flora and influence lactulose metabolism.