There are several well-documented cases of acute irreversible renal failure involving renal calcium phosphate deposits after the use of bowel preparations containing sodium phosphate (e.g., Colophos®).
- Neither randomised clinical nor epidemiological studies have established an
association between sodium phosphate use and renal damage in patients without preexisting renal dysfunction.
- However, it is likely that patients with preexisting renal dysfunction and other risk factors were not sufficiently represented and analysed in these studies, and may be at increased risk of (further) renal damage through sodium phosphate.
- Recommendations for clinical practice:
1. Routine determination of renal function through GFR estimation before prescription of bowel cleansing preparations containing sodium phosphate.
2. If sodium phosphate is administered, sufficient hydration is crucial: 2 L of fluids should be consumed with each 90 ml bottle of Colophos®.
3. Sodium phosphate should not be used in patients with preexisting renal dysfunction (GFR <60 ml/min), and in those with other risk factors (heart failure, concomitant use of ACE inhibitors, angiotensin receptor blockers and diuretics, preexisting dehydration and electrolyte disorders, old age). Bowel preparations containing polyethylene glycol (e.g., Cololyt®) should be given to these patients.