Transient alterations in plasma sodium concentrations with NER1006 bowel preparation: an analysis of three phase III, randomized clinical trials

BACKGROUND: This analysis characterized changes in sodium levels in patients receiving the 1 L polyethylene glycol-based preparation NER1006. METHODS: Data were pooled from three phase III, randomized clinical trials. A post hoc subanalysis included adults who received a 2-day split-dose (evening/morning) NER1006 regimen, a 1-day split-dose (morning only) regimen, or evening-before regimen and had an increase in sodium concentrations from normal to above the upper limit of normal (143–148 mmol/L) at ≥ 1 of three post-treatment visits. Blood samples were collected at baseline, day of colonoscopy (visit 2), 2 ± 1 days post-colonoscopy (visit 3), and 7 ± 1 days post-colonoscopy (visit 4). RESULTS: A total of 214 of 1028 patients were included. Of the 214 patients, sodium concentration increased from a mean baseline value of 141.8 mmol/L to a mean of 147.1 mmol/L (median increase from baseline of approximately 5 mmol/L). The mean sodium concentration was within normal range at visit 3 (142.3 mmol/L) and visit 4 (142.4 mmol/L), as was the median sodium concentration. Overall, ~ 90% of patients had a normal serum concentration at visits 3 and 4. Based on day of colonoscopy test results, there were four adverse events involving hypernatremia (0.4% of 1028), which were mild and did not require medical intervention; sodium levels returned to normal range by visit 3. CONCLUSION: NER1006 was associated with small, transient increases in sodium levels that were not considered clinically significant. Trial registration NOCT (ClinicalTrials.gov: NCT02254486 [registered October 2, 2014]), MORA (ClinTrials.gov: NCT02273167 [registered October 23, 2014]; EudraCT number: 2014-002185-78 [registered August 13, 2014]), DAYB (ClinicalTrials.gov: NCT02273141 [registered October 23, 2014]; EudraCT Number: 2014-002186-30 [registered August 12, 2014]) SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12876-022-02484-7.