Sucralfate is well tolerated by the broader population because it passes through the digestive tract largely unabsorbed. Less than 5% of the drug enters the bloodstream, where it is cleared by healthy kidneys. However, the aluminum hydroxide component creates specific physiological complications that demand attention.
The most widespread adverse reaction is constipation, documented in roughly 2% to 4% of patients in clinical trials, though real-world community reports suggest higher frequencies during intensive multi-week courses. As highlighted in a detailed Medical News Today Report, aluminum ions exert an astringent and relaxant effect on the smooth muscle of the intestinal walls. This action slows colonic transit time, dehydrates passing stool, and leads to uncomfortable impaction.
Patients dealing with sucralfate-induced constipation are advised to increase daily water intake, incorporate soluble fiber, or utilize osmotic stool softeners such as polyethylene glycol under medical supervision.
A far more dangerous risk applies to individuals with chronic kidney disease (CKD) or end-stage renal disease (ESRD). While healthy kidneys easily clear the small amounts of absorbed aluminum, impaired renal filtration leads to gradual aluminum accumulation in tissues.
Over weeks or months, this buildup can trigger aluminum toxicity, secondary osteomalacia by interfering with bone mineralization, and dialysis-related encephalopathy. Patients with a glomerular filtration rate (GFR) under 30 mL/min should avoid regular sucralfate use unless monitored closely by a nephrologist.
