Bowel Cleansing with Oral Sodium Phosphate is a Risk Factor for Nephropathy in Acromegaly

Abstract
Because of increased risk of colorectal carcinoma, screening by colonoscopy is recommended in patients with acromegaly. Cleansing should be vigorous in these patients due to increased bowel length and delayed colonic transit time. Recently, cases of phosphate nephropathy associated with a widely preferred purgative oral sodium phosphate (OSP) have been reported. Although main risk factors for phosphate nephropathy have been described, acromegaly has not been included as a risk factor. The present case is a 63-year old male patient, who developed transient renal failure after using three doses of OSP, which increased the serum phosphate level by 8.1 mg/dL. An acromegalic patient may have many risk factors for phosphate nephropathy after OSP administration, including having high basal serum phosphate levels, increased bowel transit time, need for high purgative dosages, increased tubular phosphate reabsorption, advanced age, and concurrent administration of angiotensin converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs), and nonsteroidal anti-inflammatory drugs (NSAIDs). Physicians should be warned against the risks of using OSP in acromegalic patients, and intensive follow-up is necessary in the hospital setting soon after OSP administration. Therefore, we suggest that acromegaly should be included as a risk factor for nephropathy due to OSP in the current guidelines.