An overview of malaria transmission from the perspective of Amazon Anopheles vectors

In the Americas, areas with a high risk of malaria transmission are mainly located in the Amazon Forest, which extends across nine countries. One keystone step to understanding the Plasmodium life cycle in Anopheles species from the Amazon Region is to obtain experimentally infected mosquito vectors. Several attempts to colonise Ano- pheles species have been conducted, but with only short-lived success or no success at all. In this review, we review the literature on malaria transmission from the perspective of its Amazon vectors. Currently, it is possible to develop experimental Plasmodium vivax infection of the colonised and field-captured vectors in laboratories located close to Amazonian endemic areas. We are also reviewing studies related to the immune response to P. vivax infection of Anopheles aquasalis, a coastal mosquito species. Finally, we discuss the importance of the modulation of Plasmodium infection by the vector microbiota and also consider the anopheline genomes. The establishment of experimental mosquito infections with Plasmodium falciparum, Plasmodium yoelii and Plasmodium berghei parasites that could provide interesting models for studying malaria in the Amazonian scenario is important. Understanding the molecular mechanisms involved in the development of the parasites in New World vectors is crucial in order to better determine the interaction process and vectorial competence.

Validation of chromatographic methods: evaluation of detection and quantification limits in the determination of impurities in omeprazole.

To guarantee that an analytical procedure gives reliable, exact and interpretable information about a sample, it must be validated. Two ambiguous parameters are detection limit and quantification limit. The determination of these limits is still of great concern and there are still a variety of procedures described in the current literature. The fundamental objective of the present work is to apply the different recommendations suggested by official guidelines for the quantitative determination of omeprazole and its impurities (omeprazole sulphone and 5-hydroxy-omeprazole) in capsules and tablets using high performance liquid chromatography with UV detection. The importance of calibration linearity in the context of the quantification limit is considered, since one of the approaches, the estimated concentrations of this limit, are deduced from the regression line. The values of the detection limit and the quantification limit obtained show that, in chromatographic analyses, the best method is that based on the use of the parameters obtained from the analytical curve, which are statistically reliable. It was shown that smaller values of the detection limit and the quantification limit were obtained by the visual approach and by the method using the signal-to-noise ratio. However, these values may reflect a subjective evaluation, prone to error and large variations. This was confirmed by showing that these methods result in values that fall outside the linear range of the method.

Gastroprotective and ulcer-healing activity of oleanolic acid derivatives: in vitro-in vivo relationships.

The triterpene oleanolic acid 1 and its semisynthetic derivatives 2-7 were assessed for gastroprotective and ulcer-healing effect using human epithelial gastric cells (AGS) and human lung fibroblasts (MRC-5). The ability of the compounds to protect the AGS cells against the damage induced by sodium taurocholate (NaT), to stimulate the cellular reduced glutathione (GSH) and prostaglandin E(2) content, to enhance AGS and MRC-5 cell proliferation and to scavenge superoxide anion in vitro was studied. The cytotoxicity of the compounds was assessed towards MRC-5 and AGS cells. In addition, the gastroprotective activity of the compounds was assessed in vivo using the HCl/EtOH-induced ulcer model in mice. All the assayed compounds displayed a significant reduction of AGS cells damage after incubation with NaT. None of the studied compounds was active as a superoxide anion scavenger nor stimulated the GSH content in AGS cell cultures. Compounds 1, 2, 4 and 6 were able to increase the prostaglandin content in AGS cell cultures. Concerning the proliferation assays, a significant stimulating effect was observed for compounds 3 and 7 on AGS cells and for 1 and 7 on MRC-5 fibroblasts. Regarding cytotoxicity, derivatives 2, 4, 6 and 7 were less toxic than the parent compound oleanolic acid. Our results strongly support the predictive capacity of the in vitro assessment of gastroprotective activity allowing the reduction of experimental animals.

Preparation, characterization, and in vivo anti-ulcer evaluation of pantoprazole-loaded microparticles.

Pantoprazole is an important drug in the treatment of acid-related disorders. This work concerns the preparation and characterization of gastro-resistant pantoprazole-loaded microparticles prepared using an O/O emulsification/solvent evaporation technique. The in vivo activity of the pantoprazole-loaded Eudragit S100 microparticles was carried out in rats. Furthermore, tablets containing the microparticles were also investigated. Microparticles presented spherical and smooth morphologies (SEM) and they remained intact in the inner surface of tablets. DSC and IR analyses showed that pantoprazole was physically and molecularly dispersed in the polymer. In vivo anti-ulcer evaluation showed that the microparticles were able to protect rat stomachs against ulcer formation, while the drug aqueous solution did not present activity. Drug dissolution profiles from tablets demonstrated slower release than untabletted microparticles. Weibull equation was the best model for describing the drug release profiles from microparticles and tablets. As regards the acid protection, tablets showed a satisfactory drug protection in acid medium (61.05 +/- 8.09% after 30 min).

Development and validation of a dissolution test for rabeprazole sodium in coated tablets.

The aim of this work is to develop and validate a dissolution test for rabeprazole sodium coated tablets using a reverse-phase liquid chromatographic method. After test sink conditions, dissolution medium and stability of the drug, the best conditions were: paddle at 75 rotations per minute (rpm) stirring speed, HCl 0.1 M and borate buffer pH 9.0 as dissolution medium for acidic and basic steps, respectively, volume of 900 ml for both. The quantitation method was also adapted and validated. Less than 10% of the label amount was released in the acid step, while more than 95% was achieved over 30 min in the basic one. The dissolution profile for tablets was considered satisfactory. The dissolution test developed was adequate for its purpose and could be applied for quality control of rabeprazole tablets, since there is no official monograph.

Rabeprazole containing triple therapy to eradicate Helicobacter pylori infection on the Texas-Mexican border.

BACKGROUND: Antibiotic resistance and duration of therapy influence the success of proton-pump inhibitor-containing Helicobacter pylori eradication therapy. Clarithromycin resistance is associated with treatment failure. AIM: To examine the success of a 7-day rabeprazole-clarithromycin-amoxicillin therapy in the study population. METHODS: Adults from Ciudad Juarez with H. pylori infections identified by culture or histology received rabeprazole 20 mg, clarithromycin 0.5 g and amoxicillin 1 g, each b.d. for 7 days. Outcome was assessed by 13C-urea breath test carried out 4+ weeks after treatment. RESULTS: A total of 111 patients were enrolled and evaluated by urea breath test; 102 completed the full 7 days therapy. Two deviated from protocol, and five stopped because of adverse events. The cure rate (intention-to-treat) was 85% (95% CI: 78-91%); the per-protocol cure rate was 85% (95% CI: 78-91%). Side-effects were not serious and only 6.6% of those with adverse events stopped medication. Only three isolates were clarithromycin-resistant and none was cured. Compliance explained most of the successes. CONCLUSIONS: In the study population a 7-day rabeprazole triple eradication therapy was both effective and well-tolerated. Clarithromycin resistance was uncommon. We observed a slightly better outcome but consistent with results from recent large studies in US populations.

Clinical outcomes of eradication of Helicobacter pylori in nonulcer dyspepsia in a population with a high prevalence of infection: results of a 12-month randomized, double blind, placebo-controlled study.

Ninety-one Helicobacter pylori-positive patients with nonulcer dyspepsia were randomized to receive either lansoprazole, amoxicillin, and clarithromycin or lansoprazole and placebo. A validated questionnaire assessed dyspeptic symptoms at baseline and at 3, 6, and 12 months. Endoscopies and biopsies were performed at baseline and at 3 and 12 months. There was an overall trend, although not statistically significant, for a benefit of H. pylori eradication. Of the patients in the antibiotics group, 16 of 46 (35%) had symptomatic improvement, versus 9 of 43 (21%) in the control group (P = 0.164). In a secondary analysis, it was found that of the patients without endoscopic gastric erosions, 15 of 34 (44%) in the antibiotics group and 5 of 33 (15%) of controls had symptomatic improvement (P = 0.015). Helicobacter pylori eradication did not prove to be clinically beneficial, although a tendency to symptomatic benefit was detected. Further studies are necessary to confirm the implications of endoscopic gastric erosions in these patients.

Effect of pantoprazole administered subcutaneously on the healing of sutured gastric incisions in rats.

BACKGROUND: The properties of proton pump inhibitors most investigated are related to peptic diseases and upper gastrointestinal bleeding, but their influence on the healing of sutured gastric incisions has not been assessed. In the present study we evaluated the effect of subcutaneously administered pantoprazole on the healing of sutured gastric incisions in rats. METHODS: Sixty rats were divided into a pantoprazole group and a control group. All rats were submitted to gastric suture in the gastric body and in the gastric fundus and had their gastric pH measured. The pantoprazole group received 20 mg/kg pantoprazole and the control group received 0.9% isotonic NaCl, both subcutaneously t.i.d. Healing analysis was carried out using collagen picrosirius red F3BA staining, and breaking strength was measured on the 4th and 7th postoperative days in all groups. RESULTS: Gastric pH was higher in the pantoprazole group. In the fundus, the pantoprazole group had a higher measurement of breaking strength and a higher proportion of type-I over type-III collagen on the 7th postoperative day. In the body, the pantoprazole group had a higher proportion of type-I over type-III collagen on the 4th and 7th postoperative days. CONCLUSIONS: Pantoprazole given subcutaneously promoted a reduction in gastric acid secretion and was associated with improved healing of the sutured gastric incision in the fundus (squamous epithelium) of rats. These findings suggest that pantoprazole has healing properties in sutured gastric incisions with potential benefits in gastric surgery.

CagA status and Helicobacter pylori eradication among dyspeptic patients.

AIM: Triple therapy seems more effective in curing Helicobacter pylori infection in patients with peptic ulcer than in those with non-ulcer dyspepsia. It has been suggested that this difference depends on the expression of CagA protein that is more frequent in the former. The objective of this study was to investigate a potential association between serum CagA positivity, severity of gastric mucosal inflammation and eradication success among peptic ulcer and non-ulcer dyspepsia patients. MATERIAL AND METHOD: Patients undergoing upper gastrointestinal endoscopy for investigation of dyspepsia at the Department of Gastroenterology, Hospital Vera Cruz, between March, 2000 and March 2001 were screened. H. pylori positive patients, as diagnosed by rapid urease test and histology were included. Severity of gastric mucosal inflammation was determined and serum CagA positivity was assessed using a commercially available ELISA assay prior to H. pylori 7-day eradication therapy with lansoprazole, clarithromycin and amoxicillin (30 mg, 500 mg and 1 g b.i.d., respectively). Eradication success was determined 8-24 weeks following completion of therapy. RESULTS: Seventy-four patients were included in the study (mean age 40.8, range 18-67, female = 28). CagA positivity was observed in 48% of patients. Gastroduodenal peptic ulceration was found in 54% of patients. Serum CagA positivity was significantly higher among peptic ulcer patients (62.5%), while CagA negativity was significantly higher among non-ulcer dyspepsia patients (67.7%). Lymphocyte and eosinophil infiltration was significantly higher among CagA + patients, despite being comparable when distributed among peptic ulcer and non-ulcer dyspepsia patients. Eradication was successful in 93.2% of patients, regardless of CagA status on a per protocol analysis. Based on a per protocol analysis, eradication success was comparable among peptic ulcer and non-ulcer dyspepsia patients, regardless of CagA status. CONCLUSION: Our results support the concept that CagA positivity is associated to peptic ulcer disease and to a higher severity of lymphocyte and eosinophil infiltration. Efficacy of treatment eradication of H. pylori may not be affected by serum CagA status.

A flow-injection biamperometric method for determination of pantoprazole in pharmaceutical tablets.

A flow-injection biamperometric method for determination of pantoprazole (PTZ) in pharmaceutical tablets is reported for the first time. The reversible redox couples Fe3+/Fe2+, Fe(CN)6(3-)/Fe(CN)6(4-), Ce4+/Ce3+, VO3(-)NO2+, and I2/I- were tested as indicating redox systems for biamperometric determination of PTZ in a flow-injection assembly with optimized flow parameters. The best results were obtained using V03(-)NO2+, which showed to be a selective and sensitive biamperometric indicating system for PTZ even in the presence of excipients and antioxidants that typically are found in drugs. The analytical graph was linear (r = 0.99945) in the range from 10 to 100 mg/L using 25 mmol/L VO3(-) as the reagent and water as the carrier stream and applying 100 mV between the 2 platinum wire electrodes. The limits of detection and quantitation were 200 and 667 microg/L, respectively, with a sensibility of calibration of 22.6 mV/mg/L. The proposed method was successfully applied to determine PTZ in commercial pharmaceutical tablets with a mean relative error of 1.60% (n = 5) and mean relative standard deviation of 3.10%. Recoveries close to 100% showed good agreement between the expected amount of PTZ in tablets (40 mg) and the results found by the application of the proposed method and demonstrated that the formulations used in the tablet compositions do not interfere in the PTZ analysis. The system had good stability, with a relative standard deviation of 3.80% for 9 sequential injections of a 60 mg/L PTZ solution. A sampling rate of about 100 samples/h was obtained.

Validation of a capillary electrophoresis method for analysis of rabeprazole sodium in a pharmaceutical dosage form.

Rabeprazole sodium is an antisecretory agent that inhibits the enzyme H+/K+ ATPase present in the stomach parietal cells. There are few data about its quantitative determinations in laboratorial routines. Capillary electrophoresis is a method being used increasingly for analysis of pharmaceutical compounds, the main advantages of which are the simplicity of instrumentation, low consumption of sample and reagents, and fast analysis. The aim of this study was to develop and validate a capillary electrophoresis method for determination of rabeprazole sodium in coated tablets. The conditions used were a bare fused silica capillary with 48.0 cm length (39.5 cm effective) and 75 microm id; a 10mM, pH 9.0, sodium tetraborate run buffer; a diode array detector set at 291 nm; hydrodynamic injection (50 mbar/5 s); and a voltage of 20 kV. HP Chemstation CE rev. A.06.03 software was used for system control, data acquisition, and analysis. The method was demonstrated to be linear in the concentration range of 5.0-40.0 microg/mL (r = 0.9993), precise (interday relative standard deviation = 0.49), accurate (mean recovery = 103.1%), and specific. The limits of detection and quantitation were 1.29 and 3.91 microg/mL, respectively.

Helicobacter pylori eradication using tetracycline and furazolidone versus amoxicillin and azithromycin in lansoprazole based triple therapy: an open randomized clinical trial.

BACKGROUND: Optimal anti-Helicobacter pylori treatment has not yet been established. AIM: To evaluate H. pylori eradication using tetracycline and furazolidone versus amoxicillin and azithromycin in lansoprazole based triple therapy in northeastern of Brazil. PATIENTS AND METHODS: One hundred and four patients with H. pylori infection, as determined by rapid urease testing and histology, were randomly assigned to receive either: lansoprazole (30 mg q.d.), tetracycline (500 mg q.i.d.), and furazolidone (200 mg t.i.d.) for 7 days (LTF; n = 52); or lansoprazole (30 mg b.i.d.) and amoxicillin (1 g b.i.d.) for 1 week, plus azithromycin (500 mg q.d.) for the first 3 days (LAAz; n = 52). H. pylori eradication was assessed 3 months following completion of therapy by means of rapid urease testing, histology and a 14C-urea breath test. RESULTS: H. pylori eradication was achieved in 46 of 52 (88.4%, 95% CI: 77.5%-95.1%) patients in LTF group and in 14 of 52 (26.9%, 95% CI: 16.2%-40,1%) patients in LAAz group. On a per-protocol analysis, eradication rates were 91.8% (95% CI: 81.4%-97.3%) and 28.5% (95% CI: 17.2%-42.3%), respectively in LTF and LAAz groups. CONCLUSION: The LAAz regimen yielded unacceptably low eradication rates. On the other hand, the LTF scheme represents a suitable alternative for H. pylori eradication.

Gastroprotective effect of the Mapuche crude drug Araucaria araucana resin and its main constituents.

The resin from the tree Araucaria araucana (Araucariaceae) has been used since pre-columbian times by the Mapuche amerindians to treat ulcers. The gastroprotective effect of the resin was assessed in the ethanol-HCl-induced gastric ulcer in mice showing a dose-dependent gastroprotective activity at 100, 200 and 300 mg/kg per os. The main three diterpene constituents of the resin, namely imbricatolic acid, 15-hydroxyimbricatolal and 15-acetoxyimbricatolic acid were isolated and evaluated for gastroprotective effect at doses of 50, 100 and 200 mg/kg. A dose-related gastroprotective effect with highly significant activity (P<0.01) was observed at doses up to 200 mg/kg. At 100 mg/kg, the highest gastroprotective activity was provided by 15-hydroxyimbricatolal and 15-acetoxyimbricatolic acid, all of them being as active as the reference drug lansoprazole at 20 mg/kg. The cytotoxicity of the main diterpenes as well as lansoprazole was studied towards human lung fibroblasts (MRC-5) and determined by the MTT reduction assay. A concentration-dependent cell viability inhibition was found with IC50 values ranging from 125 up to 290 microM. Our results support the traditional use of the Araucaria araucana resin by the Mapuche culture.

Helicobacter pylori eradication using tetracycline and furazolidone versus amoxicillin and azithromycin in lansoprazole based triple therapy: an open randomized clinical trial

RACIONAL: Ainda não está estabelecida a melhor terapêutica anti-H. pylori. OBJETIVO: Avaliar a erradicação de H.pylori usando tetraciclina e furazolidona versus amoxicilina e azitromicina em terapia tríplice com lansoprazol no nordeste do Brasil. PACIENTES E MÉTODOS: Cento e quatro pacientes infectados por H. pylori, diagnosticado através do teste rápido da urease e histologia, foram selecionados aleatoriamente para receber: lansoprazol (30 mg q.d.), tetraciclina (500 mg q.i.d.), furazolidona (200 mg t.i.d.) por 7 dias (LTF; n = 52); ou lansoprazol (30 mg b.i.d.) e amoxicilina (1 g b.i.d.) por 1 semana, mais azitromicina (500 mg q.d.) nos primeiros 3 dias (LAAz; n = 52). A erradicação de H.pylori foi avaliada 3 meses após término da terapia através do teste da urease, histologia e teste respiratório usando uréia marcada com 14Carbono. RESULTADOS: A erradicação do H. pylori foi atingida em 46 de 52 (88.4%, 95% CI: 77.5%-95.1%) pacientes no grupo LTF e em 14 de 52 (26.9%, 95% CI: 16.2%-40,1%) pacientes no grupo LAAz. Na análise per-protocolo, a taxa de erradicação foi de 91.8% (95% CI: 81.4%-97.3%) e 28.5% (95% CI: 17.2%-42.3%), respectivamente no grupo de LTF e LAAz. CONCLUSÃO: O esquema com LAAz ofereceu taxas de erradicação inaceitáveis. Por outro lado, o esquema com LTF representa alternativa adequada para erradicação de H.pylori.

Helicobacter pylori eradication does not cause reflux oesophagitis in functional dyspeptic patients: a randomized, investigator-blinded, placebo-controlled trial.

BACKGROUND: The protective role of Helicobacter pylori in gastro-oesophageal reflux disease has been widely discussed. AIM: To assess the risk of reflux oesophagitis in patients with functional dyspepsia after treatment for H. pylori infection. METHODS: A randomized, placebo-controlled, investigator-blinded trial was carried out on 157 functional dyspeptic patients. Patients were randomized to receive lansoprazole, amoxicillin and clarithromycin (antibiotic group) or lansoprazole and identical antibiotic placebos (control group). Upper gastrointestinal endoscopy was performed at baseline, 3 and 12 months after randomization. The primary aim was to detect the presence of reflux oesophagitis. Analyses were performed on an intention-to-treat basis. RESULTS: A total of 147 patients (94%) and 133 (85%) completed 3 months and 12 months follow-up, respectively. The eradication rate of H. pylori was 90% in the antibiotic group (74 of 82) and 1% (one of 75) in the control group. At 3 months, reflux oesophagitis was diagnosed in 3.7% (three of 82) in the antibiotic group and 4% (three of 75) in the control group (P > 0.2). At 12 months, diagnosis was established in five new cases within the first group and in four within the second (P > 0.2). No difference was found in heartburn symptoms. CONCLUSIONS: H. pylori eradication does not cause reflux oesophagitis in this western population of functional dyspeptic patients.

New once-daily, highly effective rescue triple therapy after multiple Helicobacter pylori treatment failures: a pilot study.

BACKGROUND: Helicobacter pylori treatment failure is a growing problem in daily practice. AIM: To determine the efficacy of the combination of rabeprazole, levofloxacin and furazolidone as a rescue therapy. METHODS: Duodenal ulcer patients previously submitted, without success, to at least two H. pylori treatment regimens were included. Gastroscopy (urease test, histological examination and culture) and (13)C-urea breath test were performed. All patients received a combination of rabeprazole 20 mg, levofloxacin 500 mg and furazolidone 200 mg (two tablets) administered in a single dose in the morning for 10 days. Clinical examination and a new (13)C-urea breath test were performed 90 days after therapy. RESULTS: Twelve patients (eight females and four males), mean age 43 (30-58) years were included. Two patients failed to complete the treatment because of nausea and vomiting. Ten patients completed the study and took all the medications as advised. Culture was obtained in six patients: 100 and 83% of the samples were sensitive to furazolidone and levofloxacin, respectively. Per-protocol and intention-to-treat eradication rates were 100 and 83% (P = 0.019). CONCLUSIONS: the combination of rabeprazole, levofloxacin and furazolidone in a single daily dose for 10 days constitutes a highly-effective and low-cost alternative as a third-line therapy in patients infected with H. pylori.

Gastroprotective activity of a new semi-synthetic solidagenone derivative in mice.

The gastroprotective activity of the new semi-synthetic solidagenone derivative 15,16-epoxy8(9),13(16),14-labdatrien-7 beta-methoxy-6 beta-ol (ELMO) has been assessed on the model of HCl/EtOH-induced gastric lesions in mice. Human gastric epithelial cells (AGS) and fibroblasts (MRC-5) were used to determine its mode of action. The effect of ELMO on the prostaglandin E2 content, cellular reduced glutathione (GSH) and protection against damage induced by sodium taurocholate was assessed against AGS cells. The effect of ELMO on the growth of AGS and fibroblast cultures was evaluated. The superoxide anion scavenging capacity of the compound was studied also. The cytotoxicity of ELMO, expressed as cell viability, was assessed using two independent endpoints: neutral red uptake (NRU) and the reduction of 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) for MRC-5 fibroblasts and NRU for AGS cells. A single oral dose of ELMO (10 and 20 mg kg(-1)) inhibited the appearance of gastric lesions in mice displaying similar values to lansoprazole at 20 mg kg(-1). At 40 microM ELMO increased the prostaglandin E2 content but not GSH in AGS cells. The compound showed no effect on sodium taurocholate-induced damage and was devoid of superoxide anion scavenging activity. Concentrations of 0.5, 1, 2 and 4 microM stimulated fibroblast but not AGS cell proliferation. The compound showed weak cytotoxicity with values (IC50) of 411 (NRU) and 418 microM (MTT) for fibroblasts and 261 microM (NRU) for AGS cells. The results support further pharmacological study of this compound as a potential new anti-ulcerogenic drug.

Metabolism of omeprazole after two oral doses in children 1 to 9 months old.

Proton pump inhibitors (PPIs) have been used recently for gastrointestinal esophageal reflux disease (GERD) in children older than one year with good results. However, the pharmacokinetics of PPIs have not been studied in children less than two years old. The aim of our study was to evaluate the frequency of the main phenotypes of the metabolizing enzymes CYP2C19 and CYP3A4 in Mexican infants. Our results indicate no significant difference between the 0.5 and the 1.5 mg/kg doses. The percentage of CYP2C19-poor metabolizers was 17% in babies below 4 months and was not detected in children above 3 months. When a combined CYP2C19- and CYP3A4- phenotype was estimated, omeprazole levels were significantly higher in poor metabolizers than in extended metabolizers. The percentage of ultra-extensive metabolizers in children older than 3 months were 20% and 33% for CYP2C19 and CYP3A4 respectively, compared to only 6% and 9% respectively, in babies between 1 and 3 months old. In general children, under 4 months had higher omeprazole levels and an immature metabolism. Studies in children older than 2 years old have showed similar pharmacokinetics to adults. For children between 1 month old and up to 9 months, we suggest the use of the 0.5 mg/kg dose, since it prevents accumulation in poor metabolizers, caution is recommended to identify ultra-fast metabolizers, but this would require new studies.

[Efficacy of the dosing regimen of pantoprazole 40 mg, amoxicillin 1000 mg and clarithromycin 500 mg, twice daily for 7 days, in the eradication of Helicobacter pylori in patients with peptic ulcer]. / Eficácia do regime terapêutico empregando a associação de pantoprazol, claritromicina e amoxicilina, durante uma semana, na erradicação do Helicobacter pylori em pacientes com úlcera péptica.

AIM: This is an open label, multicenter trial to determine the efficacy of the association of pantoprazole, clarithromycin and amoxicillin to eradicate Helicobacter pylori in patients with peptic ulcer. MATERIAL AND METHODS: Seventy-one patients (36 females, 35 males, average age 41.9 years) from three Brazilian university centers (located in the cities of Belo Horizonte and Porto Alegre), with peptic ulcers confirmed by endoscopy, and infections by H. pylori proven by at least two diagnostic testings were admitted in the trial. An association of pantoprazole 40 mg, clarithromycin 500 mg and amoxicillin 1.0 g was administered to patients twice daily for 7 days. RESULTS: By the end of treatment all patients were examined for digestive symptoms, presence of adverse events, and treatment adherence. Sixty days after the end of the treatment a new endoscopy with biopsies and respiratory function testing with 13C-urea breath test was performed in order to determine the eradication rates of that microorganism. Patients showing negative results at least in the 13C-urea breath test and in one other test (urease or histology) were considered H. pylori-negative. By the end of the trial, 60/69 (87%, CI 95% = 78.9-94.8) patients had the H. pylori eradicated in the per protocol analysis and 60/71 (84.5%, CI 95% = 76-92.9) in the intention-to-treat analysis. One patient was withdrawn from the trial due to a diarrhea. Twelve (16.9%) patients showed adverse symptoms that were deemed as mild symptoms. CONCLUSION: Our conclusion is that the association of pantoprazole, amoxicillin and clarithromycin administered during 7 days is an effective and well-tolerated alternative as regards the eradication of H. pylori in patients with peptic ulcer in Brazil.

Open, randomized multicenter comparative trial of rabeprazole, ofloxacin and amoxicillin therapy for Helicobacter pylori eradication: 7 vs. 14 day treatment.

BACKGROUND: Because of the increasing resistance to clarithromycin and metronidazole, two of the antibiotics used for the eradication of Helicobacter pylori, new therapeutic alternatives are needed. The aim of this study was to determine the efficacy of a randomized, comparative trial of 7 vs. 14-day triple treatment with rabeprazole, ofloxacin and amoxicillin for H. pylori eradication. MATERIAL AND METHODS: The present authors studied 76 dyspeptic patients infected with H. pylori diagnosed by both histology and a rapid urease test. Patients were randomized to receive rabeprazole (20 mg b.i.d.), plus ofloxacin (400 mg b.i.d.) and amoxicillin (1000 mg b.i.d.) for 7 days (group 1) vs. 14 days (group 2) and were followed by 6 weeks. Eradication was assessed 4 weeks after completing the course of study treatment by the (14)C-urea breath test. Per protocol and intention-to-treat eradication rates were determined. RESULTS: For the intention to treat analysis, the eradication rate was 62.2% for group 1 and 92.3% for group 2 (p =.004). For the per protocol analysis, eradication rate for group 1 was 63.9% and for group 2 was 97.3% (p =.001). CONCLUSIONS: Triple therapy with rabeprazole, amoxicillin and ofloxacin by 14 days was efficient for H. pylori eradication and therefore deserves further study. The same regimen prescribed for 7 days had a significantly lower and unacceptable cure rate and should not be used.