Systematic review with meta-analysis: lubiprostone efficacy on the treatment of patients with constipation / Revisão sistemática com metanálise: eficácia da lubiprostona no tratamento de pacientes com constipação

ABSTRACT BACKGROUND: Lubiprostone is a type 2 chloride channel activator that has been shown to be efficacious and safe in the treatment for chronic constipation. OBJECTIVE: To systematically review randomized clinical trials (RCTs) assessing efficacy of lubiprostone for patients with chronic idiopathic constipation (CIC), irritable bowel syndrome with predominant constipation (IBS-C) and opioid-induced constipation (OIC). METHODS: Searches were conducted in PubMed, LILACS, Cochrane Collaboration Database, and Centre for Reviews and Dissemination. Lubiprostone RCTs reporting outcomes of spontaneous bowel movements (SBM) and abdominal pain or discomfort were deemed eligible. Meta-analysis was performed calculating risk ratios and 95% confidence intervals, using the Mantel-Haenszel method and random effects model. RESULTS: Searches yielded 109 records representing 93 non-duplicate publications, and 11 RCTs (978 CIC, 1,366 IBS-C, 1,300 OIC, total = 3,644) met inclusion criteria. Qualitative synthesis showed that for CIC patients, lubiprostone is superior to placebo in terms of SBM outcomes. Meta-analysis for CIC was feasible for full responder and SBM within 24h rates, indicating superiority of lubiprostone over placebo. For IBS-C, lubiprostone was significantly superior for all SBM outcomes in follow-ups ranging from 1 week-3 months. In terms of abdominal pain, lubiprostone provided significantly better symptoms relief, particularly after 1 month of treatment. For OIC, lubiprostone was more effective than placebo for both SBM and discomfort measures. CONCLUSION: Our findings demonstrated that lubiprostone is superior to placebo in terms of SBM frequency for CIC, IBS-C and OIC. In terms of abdominal symptoms, the most pronounced effect was seen for abdominal pain in IBS-C patients.

RESUMO CONTEXTO: Lubiprostona é um ativador de canal de cloreto tipo 2 que tem se demonstrado eficaz e seguro no tratamento da constipação crônica. OBJETIVO: Revisar sistematicamente ensaios clínicos randomizados (ECRs) avaliando a eficácia da lubiprostona para pacientes com constipação idiopática crônica (CIC), síndrome do intestino irritável com constipação predominante (IBS-C) e constipação induzida por opioide (OIC). MÉTODOS: Buscas foram conduzidas no PubMed, LILACS, Cochrane Collaboration Database e Centre for Reviews and Dissemination. ECRs de lubiprostona relatando desfechos de movimentos intestinais espontâneos (SBM) e dor ou desconforto abdominal foram considerados elegíveis. Metanálise foi realizada calculando razão de riscos e intervalos de confiança de 95%, utilizando o método de Mantel-Haenszel e modelo de efeitos aleatórios. RESULTADOS: As buscas identificaram 109 registros representando 93 publicações não-duplicadas e 11 ECRs (978 pacientes de CIC, 1366 de IBS-C e 1300 OIC, total = 3644) preencheram os critérios de inclusão. Síntese qualitativa mostrou que, para pacientes com CIC, a lubiprostona foi superior ao placebo em termos de desfechos SBM. Metanálise para CIC foi possível para os desfechos de responder completo e taxa de SBM em 24 horas, indicando superioridade da lubiprostona sobre o placebo. Para IBS-C, lubiprostona foi significativamente superior para todos os desfechos de SBM em tempos de seguimento variando de 1 semana a 3 meses. Em termos de dor abdominal, lubiprostona proporciono alívio dos sintomas significativamente melhor, particularmente após 1 mês de tratamento. Para OIC, lubiprostona foi mais efetiva do que placebo tanto para medidas de SBM quando de desconforto abdominal. CONCLUSÃO: Nossos achados demonstraram que lubiprostona é superior ao placebo em termos de frequência de SBM para CIC, IBS-C e OIC. Em termos de sintomas abdominais, o efeito mais pronunciado foi visto para dor abdominal em pacientes com IBS-C.

Pharmacotherapy in Patients with Chronic Constipation / 대한소화기학회지

Chronic constipation is one of the most common digestive diseases frequently observed in a clinical setting. It has been known to cause considerable damage to the quality of life of patients. Despite recent developments, there are considerable limitations in the use of constipation-modulating agents in Korea. Chloride channel inhibitors, such as lubiprostone and linaclotide, have not been introduced in Korea yet, and prucalopride and several kinds of polyethylene glycol are not covered under medical insurance. This article assesses medicines that are clinically available for the management of constipation in Korea, with a brief review of agents that have recently developed around the world.

New Generation Laxatives / 대한내과학회지

A significant proportion of chronic constipation patients are dissatisfied with their treatment. Recently, a number of new medications have been introduced for patients refractory to conventional laxatives, such as prucalopride, lubiprostone, linaclotide, and elobixibat. Prucalopride is a novel gastrointestinal prokinetic agent that acts as a 5-hydroxytryptamine type 4 (5-HT4) agonist. Compared with older nonselective 5-HT4 agonists, the higher selectivity of prucalopride for 5-HT4 receptors can reduce the risk of significant adverse cardiovascular events. Prucalopride improves stool frequency and consistency, and reduces the need for rescue medications. Lubiprostone, a chloride channel activator, increases the secretion of intestinal fluid, improves the stool frequency and consistency, and reduces straining. Linaclotide, a guanylate cyclase-C agonist, is effective in treating patients with chronic constipation and its effect on visceral sensitivity, as shown mainly in animal studies, provides an attractive pharmaceutical option for patients with irritable bowel syndrome with constipation. Elobixibat is an ileal sodium-dependent bile acid transporter inhibitor that blocks the enterohepatic circulation of bile acids, increasing the bile acid concentration in the intestine, which accelerates colonic transit and softens the stool. A phase III trial of the treatment of chronic constipation and irritable bowel syndrome with constipation is underway. The clinical application of new-generation laxatives will contribute to the management of chronic constipation refractory to conventional laxatives.

Effects of Lubiprostone on Pacemaker Activity of Interstitial Cells of Cajal from the Mouse Colon

Lubiprostone is a chloride (Cl-) channel activator derived from prostaglandin E1 and used for managing constipation. In addition, lubiprostone affects the activity of gastrointestinal smooth muscles. Interstitial cells of Cajal (ICCs) are pacemaker cells that generate slow-wave activity in smooth muscles. We studied the effects of lubiprostone on the pacemaker potentials of colonic ICCs. We used the whole-cell patch-clamp technique to determine the pacemaker activity in cultured colonic ICCs obtained from mice. Lubiprostone hyperpolarized the membrane and inhibited the generation of pacemaker potentials. Prostanoid EP1, EP2, EP3, and EP4 antagonists (SC-19220, PF-04418948, 6-methoxypyridine-2-boronc acid N-phenyldiethanolamine ester, and GW627368, respectively) did not block the response to lubiprostone. L-NG-nitroarginine methyl ester (L-NAME, an inhibitor of nitric oxide synthase) and 1H-[1,2,4]oxadiazolo[4,3,-a]quinoxalin-1-one (ODQ, an inhibitor of guanylate cyclase) did not block the response to lubiprostone. In addition, tetraethylammonium (TEA, a voltage-dependent potassium [K+] channel blocker) and apamin (a calcium [Ca2+]-dependent K+ channel blocker) did not block the response to lubiprostone. However, glibenclamide (an ATP-sensitive K+ channel blocker) blocked the response to lubiprostone. Similar to lubiprostone, pinacidil (an opener of ATP-sensitive K+ channel) hyperpolarized the membrane and inhibited the generation of pacemaker potentials, and these effects were inhibited by glibenclamide. These results suggest that lubiprostone can modulate the pacemaker potentials of colonic ICCs via activation of ATP-sensitive K+ channel through a prostanoid EP receptor-independent mechanism.

Current Issues on the Treatment of Chronic Constipation / 대한소화기학회지

Chronic constipation is a very common clinical problem with its prevalence of up to 14% in the general population. It is not a life-threatening disease, but since patient's satisfaction to the treatment is known to be as low as 50%, chronic constipation still remains a clinically challenging problem. Fortunately, many new treatments have been introduced or are to be introduced in the near future. This article will review the basic concepts and the results of recent studies on the new treatments for chronic constipation.

Lubiprostone Increases Small Intestinal Smooth Muscle Contractions Through a Prostaglandin E Receptor 1 (EP1)-mediated Pathway

BACKGROUND/AIMS: Lubiprostone, a chloride channel type 2 (ClC-2) activator, was thought to treat constipation by enhancing intestinal secretion. It has been associated with increased intestinal transit and delayed gastric emptying. Structurally similar to prostones with up to 54% prostaglandin E2 activity on prostaglandin E receptor 1 (EP1), lubiprostone may also exert EP1-mediated procontractile effect on intestinal smooth muscles. We investigated lubiprostone's effects on intestinal smooth muscle contractions and pyloric sphincter tone. METHODS: Isolated murine small intestinal (longitudinal and circular) and pyloric tissues were mounted in organ baths with modified Krebs solution for isometric recording. Basal muscle tension and response to electrical field stimulation (EFS; 2 ms pulses/10 V/6 Hz/30 sec train) were measured with lubiprostone (10(-10)-10(-5) M) +/- EP1 antagonist. Significance was established using Student t test and P < 0.05. RESULTS: Lubiprostone had no effect on the basal tension or EFS-induced contractions of longitudinal muscles. With circular muscles, lubiprostone caused a dose-dependent increase in EFS-induced contractions (2.11 +/- 0.88 to 4.43 +/- 1.38 N/g, P = 0.020) that was inhibited by pretreatment with EP1 antagonist (1.69 +/- 0.70 vs. 4.43 +/- 1.38 N/g, P = 0.030). Lubiprostone had no effect on circular muscle basal tension, but it induced a dose-dependent increase in pyloric basal tone (1.07 +/- 0.01 to 1.97 +/- 0.86 fold increase, P < 0.05) that was inhibited by EP1 antagonist. CONCLUSIONS: In mice, lubiprostone caused a dose-dependent and EP1-mediated increase in contractility of circular but not longitudinal small intestinal smooth muscles, and in basal tone of the pylorus. These findings suggest another mechanism for lubiprostone's observed clinical effects on gastrointestinal motility.