Safest Laxatives For Kidney Patients: What's The Best Option? (2024)

Constipation is a common problem for people with chronic kidney disease, and it can be caused by several factors, including dietary restrictions, comorbidities, and medications. While laxatives are typically used to manage constipation, it is important to choose the right type of laxative for kidney patients to ensure their safety and effectiveness. Some laxatives may be beneficial for improving bowel habits and gut health, but it is always recommended to consult a nephrologist or healthcare provider to determine the most suitable option.

Laxatives to avoid

Constipation is a common issue for people with chronic kidney disease, and it's important to be aware of which laxatives to avoid in this instance.

Magnesium-containing products should be avoided, as they can accumulate in patients with kidney disease. This includes Milk of Magnesia® and magnesium citrate solution.

Bulk-forming laxatives, such as psyllium, wheat bran, polycarbophil, and methylcellulose, should be used with caution. They can cause side effects such as abdominal pain, bloating, flatulence, and nausea, especially in patients with firmer stools.

Magnesium salts, while excellent osmotic laxatives, can lead to hypermagnesemia in patients with impaired renal function.

Non-absorbable carbohydrates like sorbitol, lactulose, and lactitol are also not recommended. While lactulose has shown reno-protective effects, it is not the best option for those with advanced CKD as it can lead to fluid retention.

Stimulant laxatives like anthraquinones (aloe, senna, and cascara), surfactant laxatives (docusate and castor oil), and polyphenols (sodium picosulfate, bisacodyl, and phenolphthalein) can be helpful in the short term, but there are concerns about their long-term safety and potential for abuse.

Finally, prucalopride, a selective 5-HT4 receptor agonist, should be used with caution due to its excretion via urine. Its clearance is significantly reduced in patients with moderate or severe renal impairment.

Laxatives that are safe

Constipation is a common problem for people with chronic kidney disease. This is due to a variety of factors, including the side effects of other medications, low dietary fibre intake, water-restricted diets, and reduced physical activity.

While over-the-counter laxatives are generally safe for most people, some prescription laxatives used to clean the bowel before a colonoscopy can harm the kidneys. It is important to consult a doctor or pharmacist about which medication is best for you.

Safe laxatives for kidney patients include:

• PEG3350 (Restoralax, Miralax)
• PEG3350 with Lytes (PEGLyte, GoLytely)
• Bisacodyl (Dulcolax)
• Senna (Senokot)
• Lactulose
• Docusate (Colace) – safe but not very effective

Linaclotide and plecanatide are also considered safe for patients with chronic kidney disease, as they have very limited systemic absorption. Lubiprostone has also been shown to have reno-protective effects and is considered a relatively safe and effective drug for patients with chronic kidney disease.

The impact of constipation on kidney function

Constipation is a common problem for people with chronic kidney disease, and it can have a significant impact on kidney function. It is often caused by a combination of factors, including a sedentary lifestyle, low fibre and fluid intake, medication side effects, and other health conditions such as diabetes. The impact of constipation on kidney function is an area that requires further research, but current studies suggest a link between the two.

Constipation can negatively affect a person's quality of life and impose economic burdens. It has also been associated with an increased risk of adverse clinical outcomes, such as end-stage renal disease, cardiovascular disease, and mortality. In patients with chronic kidney disease, constipation has been linked to a higher risk of developing chronic kidney disease and kidney failure.

The gut plays a crucial role in maintaining kidney health. A healthy gut contributes to the disposal of uremic toxins and the regulation of acid-base and mineral homeostasis. Constipation can disrupt these functions and contribute to excess morbidity and mortality in individuals with chronic kidney disease.

The management of constipation in patients with chronic kidney disease is challenging due to dietary and physical activity restrictions. However, it is essential to address constipation to prevent further complications. Lifestyle modifications, such as increasing fibre and fluid intake and engaging in regular exercise, can help relieve constipation. In addition, certain medications, such as lactulose and lubiprostone, have been found to have reno-protective effects and may be beneficial for individuals with chronic kidney disease.

The gut-kidney axis

Constipation is a common issue for people with chronic kidney disease, as iron and calcium tablets can cause this side effect. It is important to ask your doctor or pharmacist about the best medication to prevent constipation if you are taking a daily medicine that may cause constipation.

There are a variety of laxatives that are safe for kidney patients, including:

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

Now, onto the gut-kidney axis.

The gut microbiota communicates with the endocrine, nervous, and immune systems to regulate host homeostasis, including blood pressure and kidney functions. The gut-kidney axis is mediated through metabolism-dependent and immune pathways.

Uremia, which is elevated in CKD, affects both the composition and metabolism of the gut microbiota. This can lead to a shift in microbial metabolism to a predominantly proteolytic fermentation pattern, resulting in the production of uremic toxins. These toxins, such as indoxyl sulfate, p-cresyl sulfate, and trimethylamine-N-oxide, have been shown to have vascular and renal toxicity.

Disruption of the epithelial barrier due to gut dysbiosis can also lead to increased exposure of the host to these toxins. Dietary restrictions and gastrointestinal dysfunctions associated with CKD can further contribute to the shift in microbial metabolism.

The brain-gut-kidney axis involves connections between these organs that are mediated by descending autonomic regulation from the brain and signals from the gut and kidney, such as immune products and microbial metabolites. This axis plays a role in the maintenance of normal homeostasis, and its dysregulation has been implicated in the pathogenesis of CKD and hypertension.

Potential therapeutic strategies for CKD and hypertension that target the gut microbiota include dietary interventions, probiotics, prebiotics, synbiotics, faecal microbiota transplant, and metabolome modulation.

Pharmacological treatment options

Constipation is a common problem for people with chronic kidney disease. It is often caused by iron and calcium tablets, as well as pain medications. While over-the-counter laxatives are generally safe for most people, some prescription laxatives used to clean the bowel before a colonoscopy can harm the kidneys.

There are a variety of laxatives that are safe for kidney patients. These include:

• PEG3350 (Restoralax, Miralax)
• PEG3350 with Lytes (PEGLyte, GoLytely)
• Bisacodyl (Dulcolax)
• Senna (Senokot)
• Lactulose
• Docusate (Colace)
• Lubiprostone
• Linaclotide
• Plecanatide
• Tenapanor
• Prucalopride

Bulk-forming laxatives, such as psyllium, wheat bran, polycarbophil, and methylcellulose, can also be used relatively safely as a first-line treatment. However, they should be used with caution in patients with reduced renal function as they require increased fluid intake.

Magnesium salts are another option with excellent osmotic effects and low costs. However, they may lead to hypermagnesemia in patients with impaired renal function, so it is important to monitor magnesium levels.

Non-absorbable carbohydrates like lactulose, lactitol, and sorbitol can also promote bowel movement by increasing intestinal osmotic pressure and acidity. Several studies have shown that lactulose, in particular, has reno-protective effects and is well-tolerated by patients with CKD.

Polyethylene glycol (PEG 3350) is another non-absorbable and non-metabolizable substance that relieves constipation by softening stools and increasing the frequency of bowel movements. It is associated with minor gastrointestinal adverse events and no serious adverse events.

Stimulant laxatives like anthraquinones (aloe, senna, and cascara), surfactant laxatives (docusate and castor oil), and polyphenols (sodium picosulfate, bisacodyl, and phenolphthalein) can also be considered rescue therapies for patients resistant to conventional laxatives. However, there are concerns about their long-term safety and abuse.

Lubiprostone is a chloride channel activator that facilitates spontaneous bowel movement by enhancing intraluminal chloride ion secretion. It has also been shown to have reno-protective effects against the progression of CKD.

Linaclotide and plecanatide are guanylate cyclase-C agonists with very limited systemic absorption, making them safe for patients with CKD. They enhance gastrointestinal fluid secretion and induce spontaneous bowel movement.

Tenapanor is a sodium/hydrogen ion exchanger-3 (NHE3) inhibitor that reduces intestinal phosphate absorption. It has been shown to be safe and effective in treating constipation in patients with CKD and hyperphosphatemia.

Prucalopride is a selective 5-hydroxytryptamine receptor 4 agonist that stimulates peristalsis and accelerates gastrointestinal transit. It has been found to improve bowel function and constipation-related symptoms in patients unresponsive to conventional laxatives. However, it should be used with caution in patients with CKD as its clearance is significantly reduced in those with moderate or severe renal impairment. A reduced dose of 1 mg once daily is recommended for patients with CKD (glomerular filtration rate less than 30 mL/min/1.73 m2).

Frequently asked questions