Electrolyte Disturbances With Sodium Picosulfate Bowel Cleansing Products

Low volume bowel preparations for colonoscopy have become increasingly popular in recent years because of the greater comfort for patients who are not required to swallow large volumes of liquid. ADRAC has previously highlighted the risk of severe electrolyte disturbances in association with the use of oral sodium phosphate solution (Fleet Phospho-Soda Buffered Saline Laxative Mixture, Kwikprep) as a bowel preparation.¹ Since then, ADRAC has received reports in association with two other products (Picolax, Picoprep) which contain sodium picosulfate. Sodium picosulfate acts similarly to sodium phosphate in that it produces its cathartic effect by osmotic action in the gut. This results in a transfer of fluid and electrolytes across the gut to the gut lumen.

ADRAC has received 16 reports implicating sodium picosulfate products. Five described convulsions associated with hyponatraemia.

Another described syncope in a patient with both hyponatraemia and hypokalaemia. There have also been single reports of unconsciousness with hyponatraemia, metabolic alkalosis with hypokalaemia, and 4 of syncope and dehydration without documented electrolyte abnormalities.

Low volume sodium phosphate and sodium picosulfate products can cause marked dehydration, hyponatraemia, other electrolyte abnormalities and associated complications. Infants, the elderly, the frail and those with congestive heart failure or compromised renal function are particularly at risk. Alternative less concentrated bowel cleansing preparations should be used in these patients.

Reference

1. ADRAC. Electrolyte disturbances with oral phosphate bowel preparations. Aust Adv Drug React Bull 1997; 16: 2.