Influence of alpha-adrenoceptor antagonists therapy on stool form in patients with lower urinary tract symptoms suggestive of benign prostatic hyperplasia.

To evaluate the short-term efficacy and safety of two α1-adrenoceptor (AR) antagonists, tamsulosin and silodosin, in treating patients with untreated lower urinary tract symptoms suggestive of benign prostatic hyperplasia (LUTS/BPH), with a focus on stool form.This study was a non-blinded, open-label, prospective randomized comparative study. Tamsulosin or silodosin was administered to patients with untreated LUTS/BPH, and their efficacy and safety in the early stage of treatment were compared using the questionnaire of International Prostate Symptom Score (IPSS)/quality of life (QOL), the Gastrointestinal Symptom Rating Scale (GSRS), and the Bristol Stool Form Scale (BSFS).The per protocol set consisted of 22 patients in tamsulosin group (mean age, 70.15 ± 5.70 years) and 20 patients in silodosin group (73.00 ± 6.48 years). The total IPSS and QOL score improved within 2 weeks in both groups. Although the overall GSRS score showed no significant change in either group, "hard stools" score was significantly decreased in silodosin first at week 2, then in both groups at week 4. Furthermore, the subscale score for "constipation" was significantly decreased only in silodosin at week 4. BSFS was significantly increased at week 4 in silodosin alone.This study suggests that silodosin was associated with increased digestive symptoms such as diarrhea and loose stools. Therefore, oral drugs for BPH need to be selected by taking into consideration the possibility of digestive symptoms including both the state and type of stools.