Effectiveness and safety of lubiprostone after switching from stimulant laxatives in elderly patients with chronic constipation.

Background and Aim: Stimulant laxatives may cause electrolyte abnormalities, dehydration, and abdominal pain; their long-term use can lead to tolerance and subsequent refractory constipation. We investigated the effectiveness, safety, and quality of life after switching from stimulant laxatives to lubiprostone in elderly patients with chronic constipation (CC). Methods: This multicenter, interventional, open-label, single-arm, before-and-after comparison study enrolled 99 Japanese patients aged 65-90 years with CC who took stimulant laxatives for ≥2 weeks prior to switching to lubiprostone monotherapy. Results: The mean ± SD spontaneous defecations at Week 1 of 7.8 ± 6.2 times/week was not significantly different from that at baseline (8.3 ± 4.7). Spontaneous defecations were significantly reduced at Weeks 2 (-1.5 ± 4.0, P < 0.001) and 4 (-1.5 ± 3.7, P < 0.001). The Bristol Stool Form Scale score did not change from baseline (4.7 ± 0.9) at Weeks 1 (4.5 ± 1.3) or 4 (4.3 ± 1.3), but it did at Week 2 (4.3 ± 1.5, P < 0.05). The Patient Assessment of Constipation Quality of Life questionnaire score increased (0.36 ± 0.07, P < 0.001) after 28 days. Nausea was the only symptom that worsened from baseline and was the most frequently reported adverse drug reaction (15.2%). Conclusion: Switching to lubiprostone monotherapy for CC was not associated with significant concerns in short-term spontaneous defecation frequency and safety, but it might affect the efficacy and patient quality of life over 2 weeks. Careful treatment strategies facilitating gradual switching to lubiprostone monotherapy may be needed in patients using stimulant laxatives.

Analysis of the impact on efficacy of lubiprostone dose reduction to manage adverse events in the treatment of chronic constipation in Japan.

OBJECTIVE: To compare outcomes between two doses of lubiprostone in patients with chronic constipation (CC), to assess whether dose reduction affects efficacy. METHODS: This open-label exploratory study involved 146 patients with CC treated initially with lubiprostone 24 mcg twice daily for a planned duration of 4 weeks. Patients who experienced adverse events (AEs) had their dose reduced to 12 mcg twice daily (for 4 weeks). RESULTS: Lubiprostone dose was unchanged in 104 patients and reduced due to AEs in 42 patients. Significant differences in the mean number of bowel movements per week favored the dose-reduced group at Week 1 and end of follow-up. No between-group differences were observed over time for mean number of days per week with bowel movements or mean Bristol Stool Form Scale scores. Symptoms of abdominal bloating, strained defecation, and sensation of incomplete evacuation improved in both groups. Before dose reduction, nausea was reported by 64.3% and diarrhea by 45.2% of patients in the dose-reduced group; after dose reduction, no patients reported nausea and one patient reported diarrhea. CONCLUSION: Dose reduction of lubiprostone reduced the incidence of AEs, with no compromise to efficacy, and may be a suitable approach for patients who develop AEs during treatment.

Open-label study to evaluate the treatment continuation rate after a dose reduction of lubiprostone due to onset of adverse events.

OBJECTIVE: To investigate the continuation rate with a reduced lubiprostone dose (12 mcg twice daily, BD) after the onset of adverse events (AEs) in patients with chronic constipation (CC). METHODS: In this exploratory, open-label, multicenter study, patients with CC received lubiprostone 24 mcg BD and the dose was reduced to 12 mcg BD in subjects experiencing AEs. The primary objective was the continuation rate after dose reduction due to nausea/vomiting. Secondary objectives included the continuation rate after dose reduction due to diarrhea/any AE and efficacy, including changes in number of weekly bowel movements and Bristol Stool Form Scale. RESULTS: Of the 146 patients included in the study, 42 (28.8%) received lubiprostone 12 mcg BD (dose-reduced group) due to any AE. Thirty-six (85.7%) subjects in the dose-reduced group continued treatment and completed the study. 22/27 (81.5%) and 17/19 (89.5%) patients in whom the dose was reduced due to nausea/vomiting or diarrhea, respectively, continued treatment. There was no clinically relevant difference in efficacy after dose reduction. CONCLUSION: These results suggest that treatment withdrawal due to AEs associated with lubiprostone 24 mcg BD could be minimized in patients with CC after dose reduction to 12 mcg BD, thus resulting in improved long-term outcomes. CLINICAL TRIAL REGISTRATION: Japan Registry of Clinical Trials (https://jrct.niph.go.jp/latest-detail/jRCTs031180069).

Urocortin I is present in the enteric nervous system and exerts an excitatory effect via cholinergic and serotonergic pathways in the rat colon.

Corticotropin-releasing factor (CRF) and urocortin I (UcnI) have been shown to accelerate colonic transit after central nervous system (CNS) or peripheral administration, but the mechanism of their peripheral effect on colonic motor function has not been fully investigated. Furthermore, the localization of UcnI in the enteric nervous system (ENS) of the colon is unknown. We investigated the effect of CRF and UcnI on colonic motor function and examined the localization of CRF, UcnI, CRF receptors, choline acetyltransferase (ChAT), and 5-HT. Isometric tension of rat colonic muscle strips was measured. The effect of CRF, UcnI on phasic contractions, and electrical field stimulation (EFS)-induced off-contractions were examined. The effects of UcnI on both types of contraction were also studied in the presence of antalarmin, astressin2-B, tetrodotoxin (TTX), atropine, and 5-HT antagonists. The localizations of CRF, UcnI, CRF receptors, ChAT, and 5-HT in the colon were investigated by immunohistochemistry. CRF and UcnI increased both contractions dose dependently. UcnI exerted a more potent effect than CRF. Antalarmin, TTX, atropine, and 5-HT antagonists abolished the contractile effects of UcnI. CRF and UcnI were observed in the neuronal cells of the myenteric plexus. UcnI and ChAT, as well as UcnI and 5-HT, were colocalized in some of the neuronal cells of the myenteric plexus. This study demonstrated that CRF and UcnI act on the ENS and increase colonic contractility by enhancing cholinergic and serotonergic neurotransmission. These peptides are present in myenteric neurons. CRF and, perhaps, to a greater extent, UcnI appear to act as neuromodulators in the ENS of the rat colon.