Metabolic profile and ruminal and abomasal pH in sheep subjected to intravenous ranitidine / Perfil metabólico ruminal e pH abomasal em ovinos tratados com ranitidina por via intravenosa

Brazilian sheep production has intensified, predisposing sheep to an increased incidence of digestive disorders, such as abomasal ulcers. Ranitidine is used to prevent and treat this disease; however, there is little information on the parenteral use of this drug in adult ruminants. Few data exist on the concomitant metabolic changes and the behavior of the digestive system associated with its use. For this study, five healthy male sheep with ruminal and abomasal cannulas were used. A 5x5 Latin square experiment with a 2x2+1 factorial arrangement of the treatments was performed. Sheep treated with drug doses of 1 or 2mg/kg ranitidine administered intravenously every 8 or 12 hours were compared with the control group, was treated intravenously with 1 mL of physiological solution per 25 kg every 12 hours. Higher total protein concentrations, hemoglobin levels, as well as increased aspartate aminotransferase activity and increased abomasal pH for up to 150 min following drug administration were observed in all animals that received the drug, regardless of dose and frequency. The animals treated every 12 hours showed a decrease in leukocyte number compared with the control group and with the animals treated every 8 hours. Increased serum creatinine concentrations were observed in the animals treated every 8 hours. Treatments of 1mg/kg every 8 hours and 2mg/kg every 12 hours increased the red blood cell count and decreased the serum pepsinogen. All protocols studied were safe for healthy sheep, but 1mg/kg ranitidine every 8 hours and 2mg/kg ranitidine every 12 hours were the most effective protocols for gastric protection.(AU)

A ovinocultura brasileira tem se intensificado, o que predispõe os animais à maior incidência de transtornos digestivos, como a úlcera de abomaso. A ranitidina é utilizada na prevenção e tratamento desta afecção, no entanto há pouca informação sobre a indicação parenteral deste fármaco para ruminantes adultos. São escassas as informações a respeito das alterações metabólicas e do comportamento do sistema digestório associados ao seu uso. Para este estudo foram utilizados cinco ovinos, machos, hígidos, providos de cânula ruminal e abomasal. O delineamento foi Quadrado Latino 5x5 com arranjo fatorial de tratamentos 2x2+1. Os ovinos tratados com as doses de 1 e 2mg/kg de ranitidina administrada por via intravenosa a cada 8 ou 12 horas foram comparados aos animais do grupo controle, tratados por via intravenosa com 1mL de solução fisiológica por 25 kg a cada 12 horas. Maiores concentrações de proteína total e hemoglobina, maiores atividades de AST e aumento do pH abomasal por até 150 minutos foram observados em todos os animais que receberam o fármaco, independentemente de dose e frequência. Os animais tratados a cada 12 horas mostraram diminuição do número de leucócitos comparados aos animais tratados a cada 8 horas e aos animais do grupo controle. Observou-se aumento das concentrações de creatinina nos animais tratados a cada 8 horas. Os tratamentos 1mg/kg a cada 8 horas e 2mg/kg a cada 12 horas aumentaram o número de hemácias e diminuíram as concentrações séricas de pepsinogênio. Todos os protocolos estudados foram seguros para ovinos sadios, porém 1mg/kg de ranitidina a cada 8 horas e 2mg/kg a cada 12 horas mostraram-se mais eficientes quanto à proteção gástrica.

Comparison of Serum Prolactin Level between I.V. Ranitidne and I.V Cimetidine Administration in Albino Rabbits and Possible Role of Histamine 1 and 2 Receptors in Prolactin Secretion.

The serum prolactin levels of eighteen normal rabbits are measured by using method of RIA. The values before drug treatment are taken as the control values of each group. Prolactin levels after 15, 30 and 45 minutes of i.v. Ranitidine treated group, when compared to its own control values, are not significantly raised whereas those levels after i.v. cimetidine are raised significantly in the paired t-test. Prolactin levels of i.v.cimetidine group , when compared with iv ranitidine group by unpaired t-test, are significantly raised [t = 2.737, 4.215 and 2.834 at 10,15, 45 minutes intervals respectively, at 10 degree of freedom, (p < 0.05)]. In the comparison between i.v. cimetidine and i.v. cimetidine pretreated with i.v. diphenhydramine groups (by unpaired t- test), presence of diphenhydramine HCl can cause statistically significant reduction at 30,45 minutes (at 10 degree of freedom. t- 2.666 and 2.440 respectively, (p < 0.05). The result shows that i.v.cimetidine can significantly liberate prolactin from the Ant. Pituitary, unlike i.v. ranitidine. Central H1 and H2 receptors contribute in prolactin secretion.

Controlled delivery of ranitidine in the stomach using magnetic field / Administración controlada de ranitidina en el estómago usando campos magnéticos

An attempt has been made to localize ranitidine loaded microspheres in the stomach by magnetic means. Since ranitidine undergoes metabolism by microbial enzymes in the intestine, it is ideal to localize the controlled drug delivery system within the stomach to get uniform release and absorption of the drug for the desired period. Gelatin magnetic microspheres loaded with 9.1, 17.9, 26.3 and 33.3% w/w of ranitidine hydrochloride were prepared by emulsification-cross linking technique. The formulated microspheres were characterized by magnetite content, particle size and in vitro drug release. The efficiency of microspheres to be localized in the stomach is tested in vivo in rats. The prepared microspheres were spherical and had a size distribution from 10 to 105 µm. The in vitro study revealed the capability of microspheres to release the drug over a period of 8 to 12 hours, depending on drug loading. The release was found to be diffusion controlled and followed fickian diffusion principle. The in vivo study showed the efficiency of microspheres to be retained in the stomach over a period of 8 hours.

Se ha hecho el intento por localizar las microesferas cargadas de ranitidina en el estómago mediante medios magnéticos. Como que la ranitidina experimenta metabolismo mediante enzimas microbianas en el intestino, resulta ideal localizar el sistema de administración del medicamento controlado dentro del estómago para alcanzar la liberación y absorción uniformes del medicamento por el período deseado. Microesferas de gelatina magnética cargadas con 9.1, 17.9, 26.3 y 33.3% p/p de hidrocloruro de ranitidina, fueron preparadas mediante una técnica de emulsificación-entrecruzamiento. Las microesferas formuladas se caracterizaron por su contenido de magnetita, el tamaño de las partículas y la liberación del medicamento in vitro. La eficiencia de las microesferas a ser localizadas en el estómago se prueba in vivo en ratas. Las microesferas preparadas eran esféricas y tenían una distribución de tamaño de 10 a 105 µm. El estudio in vitro reveló la capacidad de las microesferas para liberar la droga en un período de 8 a 12 horas, en dependencia de la carga de la droga. Se halló que la liberación estaba sujeta difusión controlada y seguía la ley de Fick para la difusión. El estudio in vivo mostró la eficiencia de las microesferas para ser retenidas en el estómago por un período de 8 horas.

Poor efficacy of ranitidine bismuth citrate-based triple therapies for Helicobacter pylori eradication.

BACKGROUND: Helicobacter pylori eradication rates have tended to decrease recently possibly related with increasing antibiotic resistance. The present study investigated the efficacy of three different ranitidine bismuth citrate (RBC) based triple regimens in a population with high prevalence of H. pylori. METHODS: 300 consecutive H. pylori positive patients with non-ulcer dyspepsia were randomized into three regimens: (1) RBC 400 mg, amoxicillin 1000 mg and tetracycline 500 mg [RBC-AT], (2) RBC 400 mg, amoxicillin 1000 mg and clarithromycin 500 mg [RBC-AC], (3) RBC 400 mg, metronidazole 500 mg and tetracycline 500 mg [RBC-MT]. Tetracycline was given q.i.d, all other drugs were given b.i.d. for 14 days. Gastroscopy and (14)C-Urea breath test (UBT) were performed before enrollment and UBT only was repeated 6 weeks after the end of treatment. RESULTS: 274 patients completed the protocols. The overall 'intention to treat' and 'per protocol' H. pylori eradication rates in all subjects were 57.6% (95% CI: 52-63) and 63.1% (95% CI: 57-68), respectively. The eradication rates achieved in the groups (RBC-AT, RBC-AC and RBC-MT) were 64.4% (95% CI: 54-74), 66.2% (95% CI: 56-76), and 58.9% (95% CI: 49-68) on 'per protocol' analyses, respectively. There was no difference in eradication rates, compliance and major side effects between the groups. CONCLUSION: The current RBC-based H. pylori eradication therapy is not adequately effective.

Effects of a single low dose of ranitidine and effervescent antacids on intragastric acidity in healthy volunteers / Efectos de bajas dosis de ranitidina y antiácidos efervescentes sobre la acidez intragástrica en voluntarios sanos

Introduction/aims: We hypothesized that a combination of an effervescent antacid and ranitidine could allow immediate and long-lasting increase intragastric acidity. Our aim was to determine the effect of the combined intake of both, of a low dose ranitidine (OTC) and 5g of antacid on gastric pH. Material and methods: Twenty healthy Helicobacter pylori negative volunteers were enrolled. The study consisted in a fasting 6-hour gastric ph-metric procedure performed in two different periods: baseline (1-hour before drug) and post-drug (5-hours) after oral administration of a single dose of ranitidine (75 mg) plus 5 g of a commercial composed alkaline (sodium bicarbonate, citric acid, sodium carbonate). Results: While two subjects did not complete the pH-metry analysis due to technical reasons, 18 volunteers were finally assessed. Baseline intragastric pH (1.3±0.1) (mean±SD) rose significantly after administration of the drug (mean pH value for the whole period: 5.1±0.3; p<0.00001). The pH increased after administration of the study combination and values higher than pH 3 and pH 4 were reached immediately (median time: 27 sec, range: 0- 189 and 54 sec, range 27-3,600 sec, respectively). Gastric pH was initially maintained above 4 for 23.0±5 minutes. The mean time lapsed with pH<4 during the post-drug period was 96±17 min (32% of the total time). Conclusion: Our study confirms the fast and persistent effect produced by the administration of a combination of antacid salts plus low dose of ranitidine. We suggest that the given combination could be effeceffective, fast and safe for sporadic pyrosis or mild grastroesophageal reflux symptoms.

Introducción/objetivos: la combinación de un antiácido efervescente y ranitidina podría brindar un descenso inmediato y prolongado de la acidez intragástrica. Nuestro objetivo fue determinar el efecto de la ingesta conjunta de ambos (75 mg de ranitidina y 5 g de antiácidos) sobre el pH gástrico. Material y métodos: se incluyeron 20 voluntarios sanos, con anticuerpos anti- Helicobacter pylori negativos. Se realizó, en condiciones de ayuno, una pH-metría gástrica de 6 horas en dos períodos: basal (1 hora antes del medicamento) y post-droga (5 horas) luego de la administración oral de una dosis única de ranitidina (75 mg) + 5 g de antiácidos efervescentes (bicarbonato sódico, ácido cítrico, carbonato sódico). Resultados: dado que dos pacientes no completaron el estudio de pH por razones técnicas, se analizaron los resultados de 18 voluntarios. El pH intragástrico basal fue de 1.33±0.12 (promedio ± DS) y se elevó a 5.1±0.3 como promedio de todo el período post-droga (p<0.00001). El incremento de pH fue inmediato; así los valores de pH=3 y pH=4 fueron alcanzados en 27 seg, rango: 0-189 y 54 seg, rango 27- 3.600, respectivamente (mediana, rango). El pH se mantuvo inicialmente por encima de 4 durante 23.0±5 minutos. El tiempo con pH < 4 durante las 5 horas post-droga fue de 96± 17 minutos (32% del tiempo total). Conclusión: nuestro estudio confirma el efecto rápido y persistente determinado por la combinación de sales antiácidas y bajas dosis de ranitidina. De este modo esta asociación podría ser efectiva, rápida y segura frente a pirosis esporádica o síntomas de reflujo gastro-esofágico leve.

14-day quadruple therapy with ranitidine bismuth citrate after Helicobacter pylori treatment failure in Thailand.

BACKGROUND: A quadruple therapy with a proton pump inhibitor, bismuth, metronidazole and tetracycline is recommended as a second line therapy after Helicobacter pylori treatment failure. OBJECTIVE: To evaluate the efficacy of 14-day ranitidine bismuth citrate (RBC) base quadruple therapy after H. pylori treatment failure in Thai patients. METHOD AND MATERIAL: Between June 2003-May 2005, thirty-four patients who were H. pylori positive after first line (Omeprazole, Amoxicillin, Clarithromycin or Metronidazole) treatment failure received 14-day quadruple therapy with RBC (400 mg bid), Rabeprazole (20 mg bid), Metronidazole (500 mg tid) and Tetracycline (500 mg qid). Four weeks after completion of treatment, eradication was confirmed with 14C-urea breath test. RESULTS: There were 18 males (52.9%) and 16 females (47.1%) with a mean age of 47.3 +/- 14.6 years. Four patients dropped out due to side effects. Per-protocol eradication rate was 86.7% and the intention-to-treat eradication rate was 76.5%. Adverse effects were found in 38.2% with a bitter taste, nausea, and dizziness. The mean age in the treatment failure group was younger than that in the successful group (35.3 +/- 13.9 vs 51.1 +/- 13.9 years, p = 0.046, 95%CI, 0.3-31.5%). The abdominal symptoms were improved after eradication (82.4%). CONCLUSION: The 14-day quadruple therapy with ranitidine bismuth citrate is effective and well tolerated for the patients who failed with the Helicobacterpylori treatment. The patients with older age may receive a more favorable outcome of the treatment.

Effects of Metoclopramide and Ranitidine on Preoperative Gastric Contents in Day-Case Surgery

This prospective, randomized, double-blinded study was performed to evaluate the effects of intravenous metoclopramide and ranitidine on preoperative gastric contents in outpatients receiving intravenous anesthesia for laparoscopic gynecologic surgery. Fifteen minutes before the induction of anesthesia, the Z-M group (n=20) received 50mg ranitidine and 10mg metoclopramide intravenously and the control group (n=20) received the same volume of normal saline. Before the surgery, a 14-F multiorifice nasogastric tube was inserted to aspirate the gastric contents of patients under sedation with propofol and midazolam. The mean pH values of the gastric fluid were 2.7+/-2.0 (SD) [median 1.6 (range: 1.2-7.2)] in the control group, and 6.1+/-1.9 [median 6.8 (range 1.4-7.8)] in the Z-M group. The mean aspirated volumes (mL) were 15.3+/-10.4 (SD) [median 11.0 (range: 5.0-44.0)] in the control group, and 6.9+/-10.0 (SD) [median 4.5 (range: 0-38.0)] in the Z-M group. There were significantly more high-risk (gastric fluid volumes > 25mL and pH < 2.5) patients in the control group (4/20, 20%) than in the Z-M group (1/20, 5%). In conclusion, intravenous prophylactic ranitidine and metoclopramide may be an easy and useful method to decrease the volume while increasing the pH of gastric contents, and therefore may reduce the number of patients at risk for aspiration pneumonitis in ambulatory laparoscopic procedures who receive an anesthesia.

Effects of Metoclopramide and Ranitidine on Preoperative Gastric Contents in Day-Case Surgery

This prospective, randomized, double-blinded study was performed to evaluate the effects of intravenous metoclopramide and ranitidine on preoperative gastric contents in outpatients receiving intravenous anesthesia for laparoscopic gynecologic surgery. Fifteen minutes before the induction of anesthesia, the Z-M group (n=20) received 50mg ranitidine and 10mg metoclopramide intravenously and the control group (n=20) received the same volume of normal saline. Before the surgery, a 14-F multiorifice nasogastric tube was inserted to aspirate the gastric contents of patients under sedation with propofol and midazolam. The mean pH values of the gastric fluid were 2.7+/-2.0 (SD) [median 1.6 (range: 1.2-7.2)] in the control group, and 6.1+/-1.9 [median 6.8 (range 1.4-7.8)] in the Z-M group. The mean aspirated volumes (mL) were 15.3+/-10.4 (SD) [median 11.0 (range: 5.0-44.0)] in the control group, and 6.9+/-10.0 (SD) [median 4.5 (range: 0-38.0)] in the Z-M group. There were significantly more high-risk (gastric fluid volumes > 25mL and pH < 2.5) patients in the control group (4/20, 20%) than in the Z-M group (1/20, 5%). In conclusion, intravenous prophylactic ranitidine and metoclopramide may be an easy and useful method to decrease the volume while increasing the pH of gastric contents, and therefore may reduce the number of patients at risk for aspiration pneumonitis in ambulatory laparoscopic procedures who receive an anesthesia.

Small vocal cord polyps: completely resolved with conservative treatment.

Vocal fold polyps usually occur on the anterior or middle part of the membranous vocal fold and are the commonest laryngeal pathology requiring surgical removal. We report on six cases of small vocal polyps (4 cases angiomatous polyps and 2 gelatinous) that completely resolved using conservative treatment. Not every case of polyps requires surgical removal.

Therapeutic Effect of Low-Dose Omeprazole vs. Standard-Dose Ranitidine in Mild to Moderate Reflux Esophagitis / 대한소화기학회지

BACKGROUND/AIMS: Proton pump inhibitors (PPI) and H2-receptor antagonists (H2RA) are commonly prescribed for the treatment of mild to moderate reflux esophagitis (MMRE). There remains great controversy in their usefulness as the first choice and the appropriateness. We prospectively compared the efficacy and safety of the 8-week low-dose PPI vs. standard-dose H2RA in MMRE. METHODS: One hundred patients with MMRE were randomized to receive either low-dose of omeprazole (L-OMP: 10 mg, q.d.) or standard-dose of ranitidine (S-H2RA: 150 mg, b.i.d.) for 8 weeks. The H. pylori status using rapid urease test, histological examination and culture, reflux esophagitis (RE) grading, gastrointestinal symptoms using 4-point scale, adverse event and the standard laboratory examination were assessed at baseline and 8-week end point of therapy. RESULTS: Improvement rate of RE [intention to treat (n=82)/per protocol (n=72)] were shown in 69.1%/63.9% for L-OMP and 65.0%/63.9% for S-H2RA group (p=0.697, p=1.000). Complete healing rates of RE were 54.7%/50.0% for L-OMP and 42.5%/41.7% for S-H2RA. No significant difference in healing rate, the rapidity of symptom resolution, adverse events, and laboratory monitoring was found between the two groups. CONCLUSIONS: The low-dose omeprazole therapy produced similar healing rates and safety in the treatment of MMRE. In addition, L-OMP is advantageous in its once-a-day dosing and might be an alternative to S-H2RA, especially in Korean patients with MMRE.

comparative study of bolus administration and continuous infusion of ranitidine on gastric PH with intragastric PH-probe

The high mortality rate associated with significant bleeding from stress ulceration has promoted efforts to prevent this complication in critically ill patients. Gastric pH is a key factor in the pathogenesis of stress ulceration and maintaining a pH of 4 or greater reduces the risk for development of the gastric ulceration. Our aim was to compare effects of intravenous bolus administration and continuous intravenous infusion of ranitidine on gastric pH in critically ill patients at the intensive care unit [ICU]. Twenty patients who met the inclusion criteria were entered this prospective, randomized, cross over study. A total of 1500 gastric pH measurement was obtained for each phase of the study. Continuous infusion of ranitidine maintained a gastric pH greater than 4 over a longer period than that of bolus administration [22.1 hrs vs. 14.2 hrs, respectively; P<0.001]. The pH-monitoring device which was made locally, was comparable to a standard international device. This study showed that continuous infusion of ranitidine was more effective than administration of an equivalent dose of the drug by bolus in maintaining the appropriate gastric pH required for the prevention of stress ulceration

Menetrier's disease.

An 8-year-old girl presented with persistent vomiting, pain abdomen and generalized edema. Barium studies and gastroscopy suggested hypertrophic gastropathy. Histopathological examination pointed the diagnosis towards Menetrier's Disease. There was spontaneous remission and the child required only supportive therapy.

Eficacia de la terapia cuádruple en la erradicación del Helicobacter pylori y la prevención de la úlcera duodenal recidivante / Efficacy of quadruple therapy for eradication of Helicobacter pylori and prevention of recurring duodenal ulcer

Objetivo. El objetivo de nuestro estudio fue evaluar la eficacia del tratamiento con ranitidina asociada a tres antibióticos para la erradicación del Helicobacter pylori (Hp) contra el tratamiento de mantenimiento con ranitidina en la prevención de la recidiva de la úlcera duodenal (UD) durante un seguimiento de 12 meses. Antecedentes. Se han efectuado numerosos estudios sobre la erradicación del Hp en la mucosa gástrica y la prevención de la UD recidivante, sin embargo, no se ha establecido aún un tratamiento óptimo. Métodos. Nosotros efectuamos un estudio prospectivo y comparativo con 51 pacientes portadores de UD activa diagnosticada por endoscopía y que fueron distribuidos al azar en dos grupos. El grupo A (26 pacientes) recibió ranitidina 300 mg/día + metronidazol 1.5 g/día + furoxona 300 mg/día por cinco días durante 12 meses. En ambos grupos efectuamos endoscopía de control a las ocho semanas de iniciado el tratamiento, así como a los seis y 12 meses de su inclusión en el protocolo o antes en caso de presentar manifestaciones clínicas de recidiva de la UD. En cada endoscopía se tomaron dos biopsias del antro gástrico para la detección histológica del Hp mediante tinción de Giemsa así como de hematoxilina y eosina. Todos los pacientes dieron su consentimiento para participar en la investigación ésta fue aprobada por el Comité de Etica de nuestro hospital. El análisis estadístico se efectuó mediante X2. Resultados. Después de ocho semanas, las ulceras de todos los pacientes se encontraban cicatrizadas. El porcentaje de erradicación del Hp fue de 24/26 (92 por ciento) en el grupo A y ninguno en el grupo B(p<0.001). La reubfeccuñib por Hp ocurrió en 9/24 (37.5) durante el periodo control de 12 meses (grupo A) y de éstos un paciente tuvo recidiva de la UD. Por el contrario, los 25 pacientes del grupo B fueron persistentes positivos para el Hp y siete sufrieron recidiva de la UD (p<0.05). Ambos tratamientos fueron bien tolerados. Conclusiones. La terapia combinada de amoxicilina, metronizadol, furoxona y ranitidina es altamente efectiva para la erradicación del Hp y la prevención de la recidiva de la UD. Nuestros resultados son similares a los reportados con otros esquemas terapéuticos

Superioridad clínical del pantoprazol sobre la ranitidina en la curación de la esofagitis por reflujo grado II y III. Estudio prospectivo, doble ciego, doble pacebo. Experiencia clínica mexicana / Clinical superiority of pantoprazol over ranitidine in the treatment of reflux esophagitis grade II and III. Prospective, double blind and double placebo study. Mexican clinical experience

Objetivo. Comparar y contrastar la eficacia y tolerabilidad de un inhibidor de bomba de protones, pantoprazol, con un antagonista de los receptores H2, ranitidina, en el tratamiento de pacientes con esofagitis por reflujo moderada y severa. Antecedentes. La esofagitis por reflujo es una enfermedad común que afecta del 5 al 10 por ciento de la población mundial. El reflujo ácido juega un papel importante en el desarrollo de la enfermedad, así como las alteraciones en la motilidad del esófago y estómago. Pacientes y métodos. 315 pacientes (intento de tratamiento) con esofagitis por reflujo (Savary-Miller (SM) grados II y III) confirmada endoscópicamente fueron reclutados en este estudio por 46 investigadores mexicanos en nueve centros. Los pacientes recibieron ya sea pantoprazol 40 mg una vez al día o 150 mg de ranitidina dos veces al día en este estudio doble ciego, aleatorizado, con comparación de grupos paralelos. Los pacientes que no alcanzaron una cicatrización endoscópica completa después de cuatro semanas de tratamiento recibieron cuatro semanas adicionales. La tolerabilidad a los medicamentos fue valorada a través del informe de eventos adversos durante el estudio. Resultados. Después de cuatro semanas de tratamiento con pantoprazol el 81 por ciento de los pacientes con SMII y 67 por ciento de los pacientes con SM III habían cicatrizado; en contraste en el grupo tratado con ranitidina cicatrizaron solamente 67 y 30 por ciento respectivamente, todos los resultados están expresados en pacientes protocolo correcto. Después de ocho semanas de tratamiento los índices de cicatrización para el grupo pantoprazol se incrementaron a 94 por ciento y en el grupo de ranitidina 74 por ciento (p=0.001). La incidencia de eventos adversos fue menor del 2 por ciento en ambos grupos de tratamiento, por lo tanto encontramos que ambas terapias fueron bien toleradas. Conclusiones. El pantoprazol es superior a la ranitidina en el tratamiento de esofagitis por reflujo moderada y severa y ambos tratamientos son igualmente bien tolerados

Ranitidina, inhibidor de la permeabilidad vascular en la rata / Inhibitory effects of ranitidine on the vascular permeability in rat

La alta afinidad de la ranitidina hacia el receptor histaminérgico H2 y la sospecha de su participación en cambios de permeabilidad vascular, nos motivo a investigar si la ranitidina tiene efectos inhibitorios sobre los cambios en la permeabilidad provocados por la histamina. Para lograr este objetivo, se utilizaron 3 lotes de ratas variedad Wistar: Lote control, lote histamina y lote ranitidina + histamina. Se determinaron las concentraciones de proteínas totales, albúmina, sodio y cloro como indicadores de cambios en la permeabilidad vascular. Nuestros resultados demuestran parcialmente, que la ranitidina inhibe los incrementos de permeabilidad provocados por la histamina. Aunque clásicamente se ha atribuido al receptor H1, la regulación de la permeabilidad inducida por histamina, es probable que el receptor H2 también este involucrado tal como se demostró en este trabajo al bloquear su activación con ranitidina

Efficacy of triple therapy with PPI or H2 antagonist versus the elimination of helicobacter pylori

O Helicobacter pylori tem sido considerado importante fator nas doencas gastroduodenais e o esquema chamado triplice e o que mais se aceita no momento para a sua terapeutica. Neste estudo incluiram-se 14 pacientes portadores de gastrite cronica, 30 com ulcera gastrica e 16 com ulcera duodenal. Foram divididos em 2 grupos homogeneos para tratamento clinico, cada um com esquema bem definido: grupo A - claritromicina 250mg/2, tinidazol 250mg/2 e omeprazole 20mg em caso de gastrite e 40mg em caso de ulcera; grupo B - mesmos antibioticos e ranitidina respectivamente nas doses de 150 e 300mg. O periodo de tratamento foi de 7 dias para gastrites e 4 semanas para ulceras. Atraves de endoscopia e biopsia realizadas 30 dias depois do termino do tratamento, os 30 casos do grupo A tiveram erradicacao completa do Helicobacter pylori e cicatrizacao das ulceras. No grupo B, apenas 3 casos nao tiveram eliminacao do Helicobacter pylori. Concluiu-se que o uso de bloqueadores H2 no lugar de inibidores da bomba protonica tambem permite a obtencao de sucesso terapeutico