Poloxamer 188-Coated Ammonium Methacrylate Copolymer Nanocarriers Enhance Loperamide Permeability across Pgp-Expressing Epithelia.

Loperamide is a µ-opioid agonist with poor gastrointestinal absorption, mainly because of its modest aqueous solubility and being a P-glycoprotein (Pgp) efflux substrate. Nevertheless, studies associated with therapeutic effects strongly suggest that loperamide holds potential pharmacological advantages over traditional µ-opioid agonists commonly used for analgesia. Thus, in this Communication, we assessed in MDCK-hMDR1 cell lines the effects over loperamide uptake and efflux ratio, when loaded into Eudragit RS (ERS) nanocarriers coated with poloxamer 188 (P188). ERS was chosen for enhancing loperamide aqueous dispersibility and P188 as a potential negative Pgp modulator. In uptake assays, it was observed that Pgp limited the accumulation of loperamide into cells and that preincubation with P188, but not coincubation, led to increasing loperamide uptake at a similar extent of Pgp pharmacological inhibition. On the other hand, the efflux ratio displayed no alterations when Pgp was pharmacologically inhibited, whereas ERS/P188 nanocarriers effectively enhanced loperamide uptake and absorptive transepithelial transport. The latter suggests that loperamide transport across cells is significantly influenced by the presence of the unstirred water layer (UWL), which could hinder the visualization of Pgp-efflux effects during transport assays. Thus, results in this work highlight that formulating loperamide into this nanocarrier enhances its uptake and transport permeability.

[Una mezcla de manzanilla y anís estrella con actividad antimotilidad y antidiarreica en ratones].

INTRODUCTION: Diarrhea is a serious public health problem in Mexico and other countries. An alternative widely used in the treatment of diarrhea is the use of medicinal herbs. Infusions of chamomile and star anise, which have anti-inflammatory and antimotility properties, could help alleviate gastrointestinal disorders. OBJECTIVE: The objective of this study was to determine the effect of the mixture of infusions of star anise and chamomile on the gastrointestinal activity in mice. MATERIAL AND METHOD: Ten groups were formed with 10 mice per group. The percentage of advance of the activated charcoal administered through the intestine of the animals was evaluated. The model of diarrhea was induced with castor oil. The infusions were prepared using a mixture with a 50:50 ratio of the herbs, and were administered in a mixture of 10, 20, 40 and 80 mg/kg orally. RESULTS: The results indicate that mixtures 40 and 80 decreased the percentage of advance of activated charcoal, delayed the onset of diarrhea and decreased the number of evacuations compared to the control group. CONCLUSIONS: The study suggests that the combination of chamomile and star anise can be used as an alternative antidiarrheal treatment.

INTRODUCCIÓN: La diarrea es un serio problema de salud pública en México y otros países. Una alternativa ampliamente utilizada en el tratamiento de la diarrea es el uso de hierbas medicinales. Infusiones de manzanilla y anís estrella, que poseen propiedades antiinflamatorias y antimotilidad, podrían ayudar a aliviar los trastornos gastrointestinales. OBJETIVO: El objetivo de este estudio fue determinar el efecto de la mezcla de infusiones de anís estrella y manzanilla en la actividad gastrointestinal en ratones. MATERIAL Y MÉTODO: Se formaron 10 grupos con 10 ratones por grupo. Se evaluó el porcentaje de avance del carbón activado administrado a través del intestino de los animales. El modelo de diarrea fue inducido con aceite de ricino. Las infusiones se prepararon usando una mezcla con una relación 50:50 de las hierbas, y se administraron en una mezcla de 10, 20, 40 y 80 mg/kg por vía oral. RESULTADOS: Los resultados indican que las mezclas 40 y 80 disminuyeron el porcentaje de avance del carbón activado, retrasaron la aparición de diarrea y disminuyeron el número de evacuaciones en comparación con el grupo control. CONCLUSIONES: El estudio sugiere que la combinación de manzanilla y anís estrella se puede usar como un tratamiento antidiarreico alternativo.

Antidiarrheal effects of water-soluble proteins from Plumeria pudica latex in mice.

The water-soluble protein fraction obtained from Plumeria pudica (LPPp) latex has previously been demonstrated to have anti-inflammatory and antinociceptive effects. In the present study, LPPp was tested for activity against diarrhea induced by castor oil, prostaglandin E2 (PGE2) or cholera toxin. Different doses of LPPp (10, 20 or 40mg/kg) significantly inhibited the percentage of diarrheal stools (31.18%, 42.97% and 59.70%, respectively) induced by castor oil. This event was followed by significant reduction of both intestinal fluid accumulation (31.42%; LPPp 40mg/kg) and intestinal transit (68.4%; LPPp 40mg/kg). The pretreatment of animals with LPPp (40mg/kg) prevented glutathione and malondialdehyde alterations induced by castor oil. The effects of LPPp against diarrhea induced by castor oil were lost when the fraction was submitted to protein denaturing treatment with heat. LPPp (40mg/kg) also inhibited the average volume of intestinal fluid induced by PGE2 (inhibition of 46.0%). Furthermore, LPPp (40mg/kg) prevented intestinal fluid secretion accumulation (37.7%) and chloride ion concentration (50.2%) induced by cholera toxin. In parallel, colorimetric assays demonstrated that proteinases, chitinases and proteinase inhibitors were found in LPPp. Our data suggest that the antidiarrheal effect of LPPp is due to its protein content and is probably associated with its anti-inflammatory properties.

Is it worth adding loperamide to antibiotic treatment of traveler’s diarrhea? / ¿Vale la pena agregar loperamida al tratamiento antibiótico de la diarrea del viajero?

Travelers' diarrhea is a frequent condition, especially in those traveling to high-risk areas. Although antibiotic treatment reduces the duration of diarrhea, it has been suggested adding loperamide could further reduce the symptoms. To answer this question we used Epistemonikos, the largest database of systematic reviews in health, which is maintained by screening multiple information sources, including MEDLINE, EMBASE, Cochrane, among others. We identified two systematic reviews including 28 studies overall, of which 15 were randomized trials relevant for the question of interest. We extracted data from the systematic reviews, reanalysed data of primary studies and generated a summary of findings table using the GRADE approach. We concluded adding loperamide to antibiotic treatment might accelerate resolution of symptoms in traveler’s diarrhea with minimal or no adverse effects.

La diarrea del viajero es una patología frecuente, en especial en quienes se dirigen a regiones de alto riesgo. Si bien el tratamiento antibiótico reduce la duración del cuadro, se ha planteado que la asociación de loperamida podría reducir aún más los síntomas. Para responder esta pregunta utilizamos Epistemonikos, la mayor base de datos de revisiones sistemáticas en salud, la cual es mantenida mediante búsquedas en múltiples fuentes de información, incluyendo MEDLINE, EMBASE, Cochrane, entre otras. Identificamos dos revisiones sistemáticas que en conjunto incluyen 28 estudios primarios, de los cuales 15 corresponden a ensayos aleatorizados. Extrajimos los datos desde las revisiones identificadas y preparamos tablas de resumen de los resultados utilizando el método GRADE. Concluimos que agregar loperamida al tratamiento con antibióticos podría acelerar la resolución del cuadro, sin asociarse probablemente a efectos adversos importantes.

Guía de práctica clínica para el diagnóstico y tratamiento de la enfermedad diarreica aguda en niños menores de 5 años: versión extensa / Clinical practice guideline for the diagnosis and treatment of acute diarrheal disease in children under 5 years of age: long version

Este documento abarca temas de diagnóstico y tratamiento de la enfermedad diarreica aguda en niños menores de 5 años.

Is racecadotril effective for acute diarrhea in children? -First update. / ¿Es efectivo el racecadotrilo como tratamiento para la diarrea aguda en niños? -Primera actualización.

This article updates the December 2015 Living FRISBEE (Living FRISBEE: Living FRIendly Summary of the Body of Evidence using Epistemonikos), based on the detection of two systematic reviews not identified in the previous version. Gastroenteritis or acute watery diarrhea is usually a self-limited disease, but it is still associated to substantial healthcare costs and remains a frequent demand for medical care. Racecadotril, an intestinal enkephalinase inhibitor, has been used as treatment because it would decrease the duration of acute diarrhea and fluid loss. However there is still no evidence supporting its routine use. Searching in Epistemonikos database, which is maintained by screening 30 databases, we identified five systematic reviews including nine randomized trials relevant for our question. We combined the evidence using meta-analysis and generated a summary of findings table following the GRADE approach. We concluded racecadotril probably reduces the duration of acute diarrhea in pediatric patients, without increasing adverse effects.

Este resumen Epistemonikos (Living FRISBEE: Living FRIendly Summary of the Body of Evidence using Epistemonikos) es una actualización del resumen publicado en Diciembre de 2015, basado en la detección de dos nuevas revisiones sistemáticas que no habían sido identificadas en la versión anterior. La gastroenteritis o diarrea aguda es una enfermedad habitualmente autolimitada, pero que consume recursos sanitarios y constituye un motivo de consulta frecuente en pediatría. El racecadotrilo, un inhibidor de la encefalinasa intestinal, se ha usado como tratamiento porque disminuiría la duración de la diarrea y la pérdida de líquidos, pero no hay evidencia que justifique su uso rutinario. Utilizando la base de datos Epistemonikos, la cual es mantenida mediante búsquedas en 30 bases de datos, identificamos cinco revisiones sistemáticas que en conjunto incluyen nueve estudios aleatorizados relevantes para nuestra pregunta. Realizamos un metanálisis y tablas de resumen de los resultados utilizando el método GRADE. Concluimos que el uso de racecadotrilo probablemente disminuye la duración del cuadro de diarrea aguda en población pediátrica y que no se asociaría a mayor tasa de eventos adversos.

Cissus sicyoides: Pharmacological Mechanisms Involved in the Anti-Inflammatory and Antidiarrheal Activities.

The objective of this study was to evaluate the pharmacological mechanisms involved in anti-inflammatory and antidiarrheal actions of hydroalcoholic extract obtained from the leaves of Cissus sicyoides (HECS). The anti-inflammatory effect was evaluated by oral administration of HECS against acute model of edema induced by xylene, and the mechanisms of action were analysed by involvement of arachidonic acid (AA) and prostaglandin E2 (PGE2). The antidiarrheal effect of HECS was observed and we analyzed the motility and accumulation of intestinal fluid. We also analyzed the antidiarrheal mechanisms of action of HECS by evaluating the role of the opioid receptor, α2 adrenergic receptor, muscarinic receptor, nitric oxide (NO) and PGE2. The oral administration of HECS inhibited the edema induced by xylene and AA and was also able to significantly decrease the levels of PGE2. The extract also exhibited significant anti-diarrheal activity by reducing motility and intestinal fluid accumulation. This extract significantly reduced intestinal transit stimulated by muscarinic agonist and intestinal secretion induced by PGE2. Our data demonstrate that the mechanism of action involved in the anti-inflammatory effect of HECS is related to PGE2. The antidiarrheal effect of this extract may be mediated by inhibition of contraction by acting on the intestinal smooth muscle and/or intestinal transit.

Calea zacatechichi dichloromethane extract exhibits antidiarrheal and antinociceptive effects in mouse models mimicking irritable bowel syndrome.

Calea zacatechichi Schltdl. (Asteraceae alt. Compositae) is a Mexican plant commonly used in folk medicine to treat respiratory and gastrointestinal (GI) disorders. The objective of this study is to characterize the effect of C. zacatechichi extracts in mouse models mimicking the symptoms of irritable bowel syndrome (IBS). Powdered C. zacatechichi herb (leaves, stems, and flowers) was extracted with methanol. Methanolic extract was filtered and evaporated giving methanolic fraction. The residue was extracted with dichloromethane (DCM). Methanolic and DCM (200 mg/kg, per os) extracts were screened for their effect on GI motility in several in vitro tests, and the antidiarrheal and antinociceptive effects were assessed using mouse models. The influence of the DCM extract on motoric parameters and exploratory behaviors was also assessed. Finally, the composition of C. zacatechichi DCM extract was qualitatively analyzed using liquid chromatography-mass spectrometry (LC-MS) method. C. zacatechichi DCM extract significantly inhibited the contractility of mouse colon in vitro (IC50 = 17 ± 2 µg/ml). Administration of the DCM extract in vivo (200 mg/kg, per os) significantly prolonged the time of whole GI transit (46 ± 1 vs. 117 ± 27 min for control and DCM-treated animals, respectively; P = 0.0023), inhibited hypermotility, and reduced pain in mouse models mimicking functional GI disorders. Our findings suggest that constituents of the C. zacatechichi DCM extract exhibit antidiarrheal and analgesic activity. The extract may thus become an attractive material for isolation of compounds that may be used as a supplementary treatment for pain and diarrhea associated with IBS in the future.

Antidiarrheal activity of 19-deoxyicetexone isolated from Salvia ballotiflora Benth in mice and rats.

The antidiarrheal properties of 19-deoxyicetexone, a diterpenoid isolated from Salvia ballotiflora were evaluated on castor oil-, arachidonic acid (AA)- and prostaglandin (PGE2)-induced diarrhea in rodent models. The structure of 19-deoxyicetexone was determined by X-ray crystallography, mass spectrometry (EI-MS), as well as ultraviolet (UV-Vis), infrared (FT-IR) and nuclear magnetic resonance (NMR) spectroscopies. This compound significantly and dose-dependently reduced frequency of stooling in castor oil-induced diarrhea, and at dose of 25 mg/kg it also inhibited diarrhea induced with AA, while it had no effect on PGE2-induced diarrhea. This compound at doses of 25 mg/kg also diminished castor oil-induced enteropooling and intestinal motility, and inhibited the contraction of the rats' ileum induced by carbachol chloride at a concentration of 100 µg/mL. 19-Deoxyicetexone did not present acute toxicity at doses of 625 mg/kg. Its antidiarrheal activity may be due to increased reabsorption of NaCl and water and inhibition of the release of prostaglandins, gastrointestinal motility and fluid accumulation in the intestinal tracts of rats. These findings suggest that 19-deoxyicetexone may be used in the treatment of diarrhea, although more studies must be carried out to confirm this.

Interference with P-glycoprotein improves ivermectin activity against adult resistant nematodes in sheep.

The in vivo co-administration of ivermectin (IVM) with P-glycoprotein (P-gp) modulator agents has been shown to enhance its systemic availability. However, there is no sufficient evidence on the impact that this type of drug-drug interaction may have on the in vivo efficacy against resistant nematodes in ruminant species. The current work reports on the effects of loperamide (LPM), a P-gp modulating agent, on both IVM kinetic behaviour and anthelmintic activity in infected lambs. Eighteen (18) lambs naturally infected with IVM-resistant gastrointestinal nematodes were allocated into three (3) experimental groups. Group A remained as untreated control. Animals in Groups B and C received IVM (200mug/kg, subcutaneously) either alone or co-administered with LPM (0.2 mg/kg, twice every 12h), respectively. Individual faecal samples were collected from experimental animals at days -1 and 14 post-treatment to perform the faecal eggs count reduction test (FECRT). Blood samples were collected between 0 and 14 days post-treatment and IVM plasma concentrations were determined by HPLC. Additionally, at day 14 post-treatment, lambs from all experimental groups were sacrificed and adult gastrointestinal nematode counts were performed. FECRT values increased from 78.6 (IVM alone) to 96% (IVM+LPM). Haemonchus contortus was highly resistant to IVM. The IVM alone treatment was completely ineffective (0% efficacy) against adult H. contortus. This efficacy value increased up to 72.5% in the presence of LPM. The efficacy against Trichostrongylus colubriformis increased from 77.9% (IVM alone) to 96.3% (IVM+LPM). The described favorable tendency towards improved anthelmintic efficacy was in agreement with the enhanced IVM plasma availability (P<0.05) and prolonged elimination half-life (P<0.05) induced by LPM in infected lambs. A LPM-induced P-gp modulation increases IVM systemic exposure in the host but also it may reduce P-gp efflux transport over-expressed in target resistant nematodes.

Loperamide plus azithromycin more effectively treats travelers' diarrhea in Mexico than azithromycin alone.

BACKGROUND: Because the combination of loperamide and some antimicrobials has proven to be more efficacious than the antimicrobial agent alone in the treatment of travelers' diarrhea, we set out to prove loperamide plus azithromycin was more efficacious than azithromycin alone. METHODS: During the summers of 2002 to 2003, 176 US adults recently arrived in Guadalajara, Mexico were enrolled in a prospective, double-blinded, randomized trial of the treatment of acute diarrhea. Subjects received single doses (1,000 or 500 mg) of azithromycin or a single 500 mg dose of azithromycin plus loperamide. Subjects gave a pre- and post-treatment stool sample for analysis and maintained daily diaries of symptoms and passage of stools. RESULTS: The duration of diarrhea was significantly (p=0.0002) shorter following treatment with azithromycin plus loperamide (11 h) than with either dose of azithromycin alone (34 h). In the first 24 hours, the average number of unformed stools passed was 3.4 (azithromycin alone) and 1.2 (combination) for a significant (p<0.0001) difference of 2.2 unformed stools. This difference equated with 20% of azithromycin-treated subjects continuing to pass six or more unformed stools in the first 24 hours post-treatment compared with only 1.7% of combination-treated subjects. CONCLUSIONS: For the treatment of travelers' diarrhea in an Escherichia coli predominant region of the world, a single 500 mg dose of azithromycin appeared as effective as a 1,000 mg dose. Loperamide plus 500 mg of azithromycin was safe and more effective than either dose of azithromycin. To realize the substantial clinical benefit that accrues to a subset of subjects, we feel loperamide should routinely be used in combination with an antimicrobial agent to treat travelers' diarrhea.

A study of the antidiarrheal properties of Loeselia mexicana on mice and rats.

Antidiarrheal properties of hexane, chloroform, methanol and aqueous extracts from Loeselia mexicana were studied using mice and rats as animal models. Flavones and sesquiterpenlactones were detected in the chemical screening of the aqueous extract. Diarrhea was induced by castor oil or MgSO4. The methanol extract diminished diarrhea in mice induced by MgSO4, while the aqueous extract showed an effect on castor-oil-induced. The aqueous extract also reduced castor-oil-enhanced intestinal transit and inhibited defecation of normal mice. The results obtained showed a symptomatic relief of diarrhea.

Community pharmacists' knowledge and dispensing recommendations for treatment of acute diarrhoea in Trinidad, West Indies.

Using a hypothetical case presentation of a patient with acute diarrhoea, community pharmacists in Trinidad were asked about their knowledge and dispensing recommendations to manage acute diarrhoea. Oral rehydration salts (ORS) were recommended by 86% (79), but more pharmacists would recommend ORS as the first choice therapy alone, for children (70%) than adults (33%) (p < 0.01). Antimotility agents as a first choice therapy alone or with ORS would be given to more adults (60%) than children (10%) (p < 0.01), and more adults (59%) than children (33%) would receive cotrimoxazole. Pharmacists (93%) would counsel on preparation, storage and treatment schedule for ORS, but not on discontinuing (32%) or continuing ORS (4%). Despite 51 pharmacists knowing the WHO guidelines to treat acute diarrhoea, only 23 dispensed in accordance. Educational re-enforcement to manage acute diarrhoea and dispensing practices of medications are necessary for pharmacists who are the first patient contact in Trinidad.

Intestinal anti-spasmodic effect of a phytodrug of Psidium guajava folia in the treatment of acute diarrheic disease.

Ancestral medicinal use of guava (Psidium guajava L. Fam. Myrtaceae) is today supported by numerous biomedical studies concerning the properties of leaf extracts. However, insufficient clinical studies are reported on the use of this plant resource in the treatment of gastrointestinal ailments. The present work reports a randomized, double-blinded, clinical study performed to evaluate the safety and efficacy of a phytodrug (QG-5) developed from guava leaves, standardized in its content of quercetin and orally administered to a group of adult patients with acute diarrheic disease. Capsules containing 500 mg of the product were administered to 50 patients every 8 h during 3 days. Results obtained showed that the used guava product decreased the duration of abdominal pain in these patients.

A multinational comparison of racecadotril and loperamide in the treatment of acute watery diarrhoea in adults.

BACKGROUND: Racecadotril (acetorphan) is an orally active, potent inhibitor of enkephalinase, which exerts an antihypersecretory effect without increasing intestinal transit time. The aim of this study was to compare the efficacy, safety and tolerability of racecadotril with those of loperamide by assessing their effects on the resolution of the signs and symptoms of diarrhoea in patients in developing countries who had acute watery diarrhoea of less than 5 days' duration. METHODS: 945 outpatients from 21 centres in 14 countries received racecadotril (100 mg) or loperamide (2 mg) three times daily in a single-blind study. Duration of diarrhoea was the primary measure of efficacy; secondary criteria were overall clinical response, occurrence and duration of abdominal pain and distension, and occurrence of other associated signs and symptoms. Occurrence of constipation and adverse events were the main safety assessments. RESULTS: Diarrhoea resolved rapidly with both racecadotril and loperamide (55.0 h in both groups), 92% of patients on racecadotril and 93% on loperamide being treatment successes. Racecadotril produced a significantly greater reduction in abdominal pain and distension than loperamide (P = 0.024 and 0.03, respectively). The duration of abdominal distension was significantly shorter with racecadotril (5.4 versus 24.4 h; P = 0.0001), and constipation was also significantly less frequent (16% versus 25%; P = 0.001). One-hundred-and-eighty patients (19%) experienced one or more adverse event during the study: 67 (14.2%) in the racecadotril group and 113 (23.9%) in the loperamide group (P = 0.001). CONCLUSIONS: Racecadotril resolved the symptoms of acute diarrhoea rapidly and effectively, and produced more rapid resolution of abdominal symptoms and less constipation than loperamide.

Loperamide-induced enhancement of moxidectin availability in cattle.

Moxidectin (MXD) is a milbemycin endectocide compound active at extremely low dosages against a wide variety of nematode and arthropod parasites. Different pharmacological approaches are currently being tested to delay the bile-faecal elimination and to obtain increased systemic availability for endectocide molecules in ruminants. Loperamide (LPM) is an opioid derivative, whose main pharmacological action is to abolish intestinal propulsive peristaltic waves. The influence of LPM on the pattern of faecal excretion of MXD and on its plasma disposition following intravenous (i.v.) and subcutaneous (s.c.) administrations to cattle was evaluated in the current work. Parasite-free calves were treated with MXD given either alone at 200 microg/kg by i.v. (Experiment 1) and s.c. (Experiment 2) administrations or coadministered with LPM subcutaneously injected at 0.4 mg/kg. Blood and faecal samples were collected over a period of 20 (Experiment 1) and 40 (Experiment 2) days post-treatment. The recovered plasma and faecal samples were extracted and analysed by high-performance liquid chromatography (HPLC) using fluorescence detection. Significantly higher MXD plasma concentrations were obtained after the coadministration of MXD + LPM compared with treatments with MXD alone by both routes. The higher MXD plasma concentration profiles measured after the coadministration with LPM accounted for the significantly higher AUC values obtained following the i.v. (> 46%) and s.c. (> 38%) treatments. A reduced MXD body clearance was observed in the presence of LPM. The appearance of MXD in faeces was significantly delayed after the i.v. and s.c. coadministrations of MXD with LPM (T(1/2app)=5.87 and 10.6 h, respectively) than that observed after the treatment with MXD alone (T(1/2app)=3.48 and 5.12 h). A delayed MXD peak concentration in faeces collected from MXD + LPM-treated animals compared with those receiving MXD alone, was observed. The delayed intestinal transit time caused by LPM and a potential competition between MXD and LPM for the P-glycoprotein-mediated bile/intestinal secretion processes, may account for the enhanced MXD systemic availability measured in cattle in the current work.

Antidiarrhoeal activity of Waltheria americana, Commelina coelestis and Alternanthera repens.

The antidiarrhoeal activity of the hexane, chloroform, methanol and aqueous extracts of Waltheria americana, Commelina coelestis and Alternathera repens, was tested on mice with diarrhoea induced by castor oil and MgSO4. The methanol extract of C. coelestis and A. repens and aqueous extract of A. repens, presented antidiarrhoeal effect, monitored by number of liquid feces defecated and intestinal transit of a suspension of graphite with castor oil in Wistar rats.