Laxatives And Kidney Function: Exploring The Connection

Constipation is a common issue for those with chronic kidney disease, and laxatives are often used to treat it. While over-the-counter laxatives are generally considered safe, certain prescription laxatives can be harmful to the kidneys.

There is a dearth of research on the effects of laxative use on kidney function in patients with advanced chronic kidney disease. However, one study found that laxative use was associated with a faster decline in kidney function, although the difference was minimal and may not be biologically significant.

Laxative abuse can lead to hypokalemia and volume depletion, which have been linked to renal insufficiency and, in rare cases, severe renal failure requiring hemodialysis.

Laxative use and kidney function in patients with chronic kidney disease

Constipation is a common problem for people with chronic kidney disease (CKD), with a prevalence of 29% in patients on peritoneal dialysis and 63% in those on hemodialysis. This is due in part to dietary restrictions, comorbidities, and medications. Laxatives are typically used to manage constipation, but their effect on kidney function in advanced CKD is unclear.

A study by Keiichi Sumida et al. examined the association between laxative use and longitudinal changes in kidney function among patients with advanced CKD. They found that laxative use was associated with a slightly faster decline in estimated glomerular filtration rate (eGFR) compared to non-use, but the difference was minimal and may not be clinically significant.

Another study by Ra Ri Cha et al. suggests that constipation has a negative impact on kidney function and is associated with an increased risk of developing advanced stages of CKD. They also mention that certain types of laxatives, such as magnesium salts, bulk-forming laxatives, and osmotic laxatives, may have insufficient efficacy and potential adverse effects in CKD patients.

In conclusion, while laxative use may be associated with a slightly faster decline in kidney function, the difference is negligible, suggesting the renal safety profile of laxatives in advanced CKD patients. However, certain types of laxatives may be more beneficial than others, and further research is needed to optimize laxative use in this population.

Laxative abuse and renal failure

Laxative abuse can lead to hypokalemia and volume depletion, which in turn can cause rhabdomyolysis. While laxative abuse has been associated with renal insufficiency, it is not typically severe enough to require haemodialysis. However, in rare cases, it can lead to severe renal failure, especially when combined with profound volume depletion.

A case study of a 27-year-old woman with a history of laxative abuse illustrates this point. She presented with severe renal failure associated with hypokalemia and volume depletion. Her condition worsened to the point where she required acute haemodialysis due to worsening acidosis, despite assisted ventilation.

Another case study describes a 42-year-old woman with chronic kidney disease resulting from chronic laxative abuse in the context of anorexia nervosa. She developed an anuric acute kidney injury (AKI) that required haemodialysis and experienced another mild AKI episode two months later. Both AKI episodes involved severe to moderate hypokalemia, volume depletion, and mild rhabdomyolysis.

While these cases demonstrate the potential for laxative abuse to cause severe renal issues, it is important to note that the majority of drugs used to treat constipation are generally considered safe when used appropriately, without abuse, and under medical supervision.

Safe laxatives for patients with chronic kidney disease

Constipation is a common problem for people with chronic kidney disease, and laxatives are often used for treatment. However, it is important to be cautious when selecting a laxative as some may not be suitable for those with kidney disease.

Safe Laxatives

The following laxatives are considered safe for patients with chronic kidney disease:

• PEG3350 (Restoralax®, Miralax®)
• PEG3350 with Lytes (PEGLyte®, GoLytely®)
• Bisacodyl (Dulcolax®)
• Senna (Senokot®)
• Lactulose

Laxatives to Avoid

• Milk of Magnesia®
• Magnesium citrate solution
• Fleet Phospho-Soda®
• Metamucil®

It is also important to note that while Docusate (Colace®) is considered safe, it may not be very effective.

Additionally, when taking any new medication, it is always important to consult with a doctor or pharmacist to ensure it is suitable for your individual needs.

Prevalence of laxative use in patients transitioning to dialysis

Constipation is highly prevalent in patients with chronic kidney disease (CKD), especially those with end-stage renal disease (ESRD) receiving dialysis. This is due in part to dietary restrictions, comorbidities, and medications. Laxatives are typically used to treat constipation, but little is known about their use and associated factors in patients with advanced CKD transitioning to ESRD.

A retrospective cohort study of 102,477 US veterans transitioning to dialysis between October 2007 and March 2015 examined the proportion of patients who filled a prescription for any type of laxative within each 6-month period over 36 months pre- and post-transition to ESRD. The proportion of patients prescribed laxatives increased as patients progressed to ESRD, peaking at 37.1% in the 6 months immediately following ESRD transition, then remaining fairly stable throughout the post-ESRD transition period.

Among laxative users, stool softeners were the most commonly prescribed (∼30%), followed by hyperosmotics (∼20%), stimulants (∼10%), bulk formers (∼3%), chloride channel activator (<1%) and several combinations of these. The use of anticoagulants, oral iron supplements, non-opioid analgesics, antihistamines, and opioid analgesics were among the factors independently associated with pre-ESRD laxative use.

The use of laxatives increased considerably as patients neared transition to ESRD, likely mirroring the increasing burden of drug-induced constipation during the ESRD transition period. These findings may provide novel insights into better management strategies to alleviate constipation symptoms and reduce medication requirements in patients with advanced CKD.

Factors associated with laxative use in patients transitioning to dialysis

Constipation is highly prevalent in patients with chronic kidney disease (CKD), especially in its advanced stages, due to dietary restrictions, comorbidities, and medications. Laxatives are typically used to treat constipation, but their effect on kidney function is not well understood.

A retrospective cohort study of US veterans with advanced CKD transitioning to dialysis found that laxative use within 2 years before dialysis initiation did not significantly impact the decline in estimated glomerular filtration rate (eGFR). This indicates that laxatives are safe for patients with advanced CKD transitioning to dialysis and may even be used to treat constipation, which has been linked to adverse kidney outcomes.

In another study, researchers examined the association between laxative use and the risk of dyskalemia (abnormal potassium levels in the blood) in patients with advanced CKD transitioning to dialysis. They found that laxative use was not associated with a risk of hypokalemia (low potassium levels) but was associated with a lower risk of hyperkalemia (high potassium levels). This suggests that laxatives may play a role in managing potassium levels in patients with advanced CKD.

A separate study of 102,477 US veterans transitioning to dialysis between October 2007 and March 2015 found that the use of laxatives increased as patients progressed to end-stage renal disease (ESRD), peaking at 37.1% in the 6 months immediately following the transition. The use of certain medications, such as anticoagulants, oral iron supplements, and opioid analgesics, was associated with a higher likelihood of laxative use before transitioning to ESRD.

Overall, these studies suggest that laxative use is common in patients with advanced CKD transitioning to dialysis and may be a safe and effective way to manage constipation and hyperkalemia in this population. However, further research is needed to confirm these findings and determine the optimal use of laxatives in this patient group.

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