Assessment of the pharmacokinetics, removal rate of hemodialysis, and safety of lactulose in hemodialysis patients

Pharmacologic Treatment of Chronic Constipation

Chronic constipation is a common disease that can impair the quality of life, with a prevalence of 14% globally and 16.5% in South Korea. Straining, hard stools, the sensation of incomplete evacuation, the sensation of anorectal blockage, and manual maneuvers to facilitate defecation are the related symptoms of chronic constipation. On the other hand, medications commonly referred to as laxatives are the essentials of treatment for constipation compared to non-pharmacological treatment, such as lifestyle modifications, biofeedback, or surgery. Unfortunately, there is still an unmet need to determine if pharmacological treatment for constipation is being administered appropriately. Therefore, there are many disadvantages as to whether the indications and side effects of laxatives are adequately considered and prescribed as the primary treatment modality for constipation in a real clinical situation in Korea. Laxatives are generally recommended as the next step for patients in whom organic causes have been excluded and have not responded to initial non-pharmacologic therapies such as dietary fiber intake and exercise. Laxatives can be classified as bulk-forming laxatives, osmotic laxatives, stimulant laxatives, and other novel laxatives. On the other hand, there are distinct mechanisms underlying constipation, and appropriate administration is the most decisive. Therefore, the present investigators prepared this review to discuss appropriate pharmacological strategies for chronic constipation in Korea. Moreover, this paper also includes suggestions for appropriate pharmacological treatment options for special patient populations.

Constipation in Patients With Chronic Kidney Disease

Constipation is a frequent symptom in patients with chronic kidney disease (CKD). This review outlines the mechanisms and management of constipation in patients with CKD from a physician's perspective. Common causes of constipation in patients with CKD include concomitant medications, low dietary fiber intake, water-restricted diet, lack of physical activity, altered gut microbiota, and reduced gastrointestinal motility. Constipation has a negative impact on overall health, and, in particular, the presence of constipation has been associated with worsening kidney function and increased risk of developing advanced stages of CKD. Although lifestyle and dietary modifications may not always be practical for patients with CKD, they are recommended because they are beneficial as they lower mortality in patients with CKD. The use of laxatives containing magnesium salts, bulking agents, and osmotic laxatives may have insufficient efficacy and may be associated with adverse effects. In contrast, lactulose and lubiprostone have been shown to exhibit reno-protective effects. Linaclotide and plecanatide have very limited systemic absorption and appear safe in patients with CKD. Tenapanor reduces paracellular intestinal phosphate absorption in addition to blocking sodium uptake by enterocytes, and provides additional benefit in patients patients with CKD who have hyperphosphatemia and constipation. Prucalopride leads to improvements in bowel function and constipation-related symptoms in cases in which response to conventional laxatives are inadequate. However, the dose of prucalopride should be reduced to 1 mg once daily for patients with CKD. In conclusion, there are important advances on the impact and treatment of constipation in patients with CKD.

The Impact of Renal Function on Hepatic Encephalopathy Following TIPS Placement for Refractory Ascites

BACKGROUND

The impact of renal function on hepatic encephalopathy (HE) following transjugular intrahepatic portosystemic shunt (TIPS) placement for refractory ascites is poorly understood. We investigated the role of renal function on HE following TIPS placement.

METHODS

A retrospective study was performed for patients undergoing TIPS for refractory ascites from 2007-2019. Patients were stratified by GFR at time of TIPS placement and by whether they were on hemodialysis (HD). Chronic kidney disease (CKD) stage 3 or higher was defined as pre-TIPS GFR < 60 for at least 3 months. Logistic regression analyses were used to identify the role of GFR and CKD at time of TIPS placement on HE within 60 days post TIPS placement.

RESULTS

Among 201 TIPS patients for refractory ascites (61% male; mean age 59.1), 78 (39%) patients were in CKD, and 16 (21%) were on HD. Mean GFR at time of TIPS placement was 62.7 ± 28.2 for all non-HD patients (n = 185). Compared with the GFR ≥ 90 group, GFR < 30 or HD (OR, 3.56; 95%CI, 1.19-10.7; p = 0.023) and CKD (OR, 2.52; 95%CI, 1.40-4.53; p = 0.002) at time of TIPS placement were significant predictors of post-TIPS placement HE within 60 days. GFRs between 30-60 and 60-90 were not significant predictors.

CONCLUSIONS

In TIPS patients for recurrent ascites, patients with acutely impaired renal function or chronic renal dysfunction were at an increased risk for HE after TIPS.