Effects of β3 Agonists and Anticholinergic Drugs on Defecation in Patients With Overactive Bladder

Abstract

Background/Aim: In clinical practice, constipation is one of the most frequent adverse events caused by drugs for overactive bladder (OAB). The occurrence of constipation greatly deteriorates the patient's quality of life. The aim of the study was to evaluate and compare the effects of three commonly used β3 agonists and anticholinergic drugs on the defecation status in patients with OAB. Patients and Methods: We retrospectively reviewed the defecation status in patients who received mirabegron, solifenacin, or fesoterodine for OAB. We evaluated changes in the (a) urological parameters using the OAB symptom score (OABSS) and (b) defecation status using the Bristol Stool Form Scale (BSFS) and constipation scoring system (CSS) following 12 weeks of drug administration. Results: We analyzed data from 165 patients (mirabegron=56, fesoterodine=52, and solifenacin=57). The solifenacin group showed a significant decrease in BSFS (from 3.2±1.0 at baseline to 2.3±1.2 post-treatment) and an increase in hardened stools (p<0.001). Elimination worsened as assessed by almost all items, and the total modified CSS scores worsened significantly from 4.8±2.6 points at baseline to 8.0±4.8 points after 12 weeks of solifenacin treatment (p<0.001). The mirabegron group showed no changes in any of the CSS items. In the fesoterodine group, the CSS scores for "completeness" and "assistance" increased significantly after treatment (p<0.001 and p=0.013, respectively). Conclusion: All three drugs were effective for OAB. Mirabegron had almost no effect on constipation; fesoterodine, an anticholinergic drug, also had hardly any effect on defecation.Overactive bladder (OAB) is a symptom syndrome characterized by urinary urgency, with or without urgency incontinence (1). The prevalence of OAB increases with age, and some epidemiological surveys suggest it to be 16-19% (2, 3). β3-adrenergic receptor agonists and anticholinergic drugs are standard drug therapies for OAB worldwide. However, the persistence of drugs for OAB is lower than that of drugs for chronic diseases such as hypertension and diabetes (4). Furthermore, compared to β3-adrenergic receptor stimulants, anticholinergic drugs have a significantly lower continuation rate due to adverse events associated with them in the early phase of administration (5).The adverse events associated with anticholinergic drugs include dry mouth, constipation, dementia, and dysuria. Among them, constipation has the greatest effect on patient satisfaction (6). While there are several meta-analyses on the risk of constipation associated with β3 adrenergic receptor agonists and anticholinergic drugs (7, 8), there are no detailed studies on the changes in the defecation status before and after the administration of these drugs.This study aimed to examine the differences in defecation status before and after administration of β3 agonists and anticholinergic drugs using an established questionnaire. Patients and MethodsEthics. The study protocol was approved by the Clinical Study Review Board of the Nagasaki ...