Management of Constipation in End-Stage Renal Disease

Safety Profile and Efficacy

The American Association for the Study of Liver Diseases (AASLD) recommends polyethylene glycol as an alternative to lactulose for hepatic encephalopathy management in critically ill patients, particularly when ileus or abdominal distention is a concern 1, 2
No dose adjustment is required for polyethylene glycol in ESRD patients, including those on dialysis, as it is eliminated through the gastrointestinal tract 1, 2
Standard dosing of polyethylene glycol is 17 grams (one capful) dissolved in 4-8 ounces of liquid once daily 1
Standard dosing of lactulose is 15-30 mL (10-20 grams) orally 2-4 times daily, titrated to achieve 2-3 soft bowel movements per day 1, 2
For rectal administration of lactulose in severe cases: 300 mL lactulose in 700 mL water (total 1 L) as an enema 1, 2

Using both polyethylene glycol and lactulose together can be beneficial in ESRD patients with refractory constipation, as they work through different mechanisms 1, 2
Polyethylene glycol acts as an osmotic agent without fermentation, while lactulose undergoes colonic fermentation and acidifies stool 1, 2
The combination may reduce the dose requirement of each individual agent, potentially improving tolerability 1
Starting regimen for combination therapy: polyethylene glycol 17 grams once daily and lactulose 15 mL twice daily, titrated upward as needed 1, 2

Electrolytes (particularly sodium and potassium) should be monitored closely, as both agents can affect fluid and electrolyte balance 1, 2
Watch for signs of dehydration and hypernatremia, especially with aggressive lactulose dosing 1, 2
Excessive lactulose can cause severe diarrhea leading to dehydration and electrolyte disturbances, which are particularly dangerous in ESRD 1, 2

No dose adjustment is needed for docusate sodium in dialysis patients, and timing relative to dialysis sessions is not clinically relevant 3

The American Journal of Kidney Diseases recommends avoiding magnesium-containing laxatives in ESRD patients due to the risk of hypermagnesemia, and also avoiding phosphate-containing bowel preparations entirely in patients with GFR <60 mL/min/1.73 m² due to the risk of acute phosphate nephropathy 4