Laxatives improve hyperkalemia in CKD patients but not in dialysis patients: Study

Memphis, TN: A recent study published in the Journal of the American Society of Nephrology reported that laxative use may lower the risk of hyperkalemia in patients with advanced chronic kidney disease (CKD). The findings support the therapeutic potential of laxatives for hyperkalemia management in advanced CKD and also support a putative role of constipation in potassium disarrays. 

Chronic kidney disease causes an increase in serum potassium levels is associated with decreased renal ion excretion. Laxatives are used as medications to reduce the progression of CKD and hyperkalemia. 

Keiichi Sumida, University of Tennessee Health Science Center, Memphis, Tennessee, and colleagues aimed to evaluate the effect of laxatives on chronic kidney disease patients to overcome hyperkalemia.

The study population encompassed 36,116 United States veterans transitioning to ESKD from 2007 to 2015 with greater than or equal to one plasma potassium measurement during the last 1-year period before ESKD transition. Using generalized estimating equations with adjustment for potential confounders, they examined the association of time-varying laxative use with risk of dyskalemia (i.e., hypokalemia [potassium <3.5 mEq/L] or hyperkalemia [>5.5 mEq/L]) versus normokalemia (3.5–5.5 mEq/L) over the 1-year pre-ESKD period. To avoid potential overestimation of dyskalemia risk, potassium measurements within 7 days following a dyskalemia event were disregarded in the analyses.

A total of 319,219 over the last one-year pre-ESKD period, there were repeated potassium measurements in the cohort study.

Out of these, it was found 12,787 (4.0%) represented hypokalemia, and 15,842 (5.0%) represented hyperkalemia; the time-averaged potassium measurement was 4.5 mEq/L.

The results of the study were:

• After multivariable adjustment, time-varying laxative use (compared with nonuse) was significantly associated with lower risk of hyperkalemia (adjusted odds ratio [aOR], 0.79)

• It was found that it was not associated with the risk of hypokalemia (aOR, 1.01). The results were robust to several sensitivity analyses.

Dr. Sumida and the team concluded that "Laxative use was independently associated with lower risk of hyperkalemia during the last 1-year pre-ESKD period. Our findings support a putative role of constipation in potassium disarrays and also support (with careful consideration for the risk-benefit profiles) the therapeutic potential of laxatives in hyperkalemia management in advanced CKD."

Reference:

The study titled, "Laxative Use and Risk of Dyskalemia in Patients with Advanced CKD Transitioning to Dialysis," is published in the Journal of the American Society of Nephrology.

DOI: https://jasn.asnjournals.org/content/32/4/950