Lactulose

Indications

Lactulose is used for: Constipation, Hepatic encephalopathy

Adult Dose

Constipation Solution: 15-30 mL (10-20 g) PO once daily; may be increased to 60 mL (40 g) once daily Portal Systemic Encephalopathy Prophylaxis 30-45 mL (20-30 g) PO q6-8hr, adjusted until 2-3 soft stools/day; if acute, may be given q1-2hr until 2-3 soft stools/day Treatment 20-30 g (30-45 mL) PO q1hr to induce rapid defecation; reduced to 20-30 g q6-8hr after defecation achieved; titrated to produce 2-3 soft stools/day

Child Dose

Constipation 0.7-2 g/kg/day (1-3 mL/kg/day) PO in divided doses; not to exceed 40 g/day (60 mL/day) Portal Systemic Encephalopathy Prophylaxis Infants: 2.5-10 mL/day (1.7-6.67 g/day) PO in divided doses; titrated to produce 2-3 soft stools/day Children and adolescents: 40-90 mL/day (26.7-60 g/day) PO in divided doses; titrated to produce 2-3 soft stools/day

Renal Dose

Administration

Contra Indications

Lactulose is contraindicated in patients with galactosaemia and intestinal obstruction.

Precautions

It should be used with caution in patients with lactose intolerance and diabetes. Lactation: Unknown whether drug is distributed into milk; use with caution

Pregnancy-Lactation

Interactions

May prevent release of mesalazine in the colon. Decreased effect with oral neomycin, antacids.

Adverse Effects

Side effects of Lactulose : Initial dosing may produce flatulence and intestinal cramps, which are usually transient. Excessive dosage can lead to diarrhoea, dehydration, nusea, vomiting, hypokalemia.

Mechanism of Action

Lactulose promotes peristalsis by producing an osmotic effect in the colon with resultant distention. In hepatic encephalopathy, it reduces absorption of ammonium ions and toxic nitrogenous compounds, resulting in reduced blood ammonia concentrations.