Polyethylene glycol-electrolyte solution is routinely prescribed for bowel cleansing.
Sodium phosphate may be an effective but potentially hazardous alternative.
Dr Mathus-Vliegen investigated the safety of prescription of either agent, without being informed of the patient's medical history.
The investigative team randomly allocated 100 consecutive patients to polyethylene glycol-electrolyte solution or sodium phosphate.
Prior to and after the bowel cleansing, blood was sampled for renal function and electrolytes.
Patients answered questionnaires about complaints and ease of intake, and endoscopists rated the quality of bowel preparation.
| Hyperphosphatemia developed in 39%, and hypocalcemia in 5% with sodium phosphate|
|Alimentary Pharmacology & Therapeutics|
The investigators identified 11 patients with a theoretical contraindication for sodium phosphate.
Of these, 9 should have been discovered by taking a detailed clinical history.
Actually, the team noted that 6 of them received sodium phosphate, with a doubling of serum phosphate levels or hypokalemia in 4.
In subjects without a contraindication to the use of sodium phosphate, hyperphosphatemia developed in 39% and hypocalcemia in 5%.
The investigators observed that patients tolerated sodium phosphate better and completed the preparation more often.
Endoscopists rated the quality of bowel preparation equivalent, except for a better cleansed ascending colon with polyethylene glycol-electrolyte solution.
Dr Mathus-Vliegen's team concludes, “The 11% potentially hazardous allocation to sodium phosphate, and the 39% incidence of hyperphosphatemia with sodium phosphate do not justify an 'over-the-counter' prescription.”
“Taking a detailed history and, when in doubt, using polyethylene glycol-electrolyte solution will safeguard against inappropriate administration of sodium phosphate.”