Do sodium phosphate enemas cause kidney failure?
Sodium phosphate enemas (SPE), often referred to by the brand name “Fleet,” have been rarely associated with acute phosphate nephropathy. In a 2012 case series highlighting the negative impact of SPE, Ori et al showed acute kidney injury in 11 elderly patients receiving Fleet enemas for constipation. These patients presented with severe hyperphosphatemia, hypocalcemia, and hypotension, with one patient presenting with a phosphorus level of 45 mg/dL (14.5 mmol/L) and calcium of 2 mg/dL (0.5 mmol/L). In a retrospective cohort from the VA system, 70,499 patients receiving either SPE alone, SPE with polyethylene glycol (PEG), or PEG alone for colonoscopy prep were analyzed for estimated glomerular filtration rate (eGFR) decline. The authors, after an adjusted analysis, indicated that there was a greater portion of long-term (>6 months) decline in eGFR in the SPE group over the PEG group, without a higher risk of acute drop in eGFR. The pathologic feature of phosphate toxicity is calcium phosphate deposition within the tubular cells, the tubular lumen, and the interstitium, leading to obstruction and inflammation. The glomeruli are left relatively intact. This has been termed acute phosphate nephropathy.
