ABSTRACT
The aim of this study was to determine the interaction between omeprazole and amoxicillin, being common agents used in the eradication regimen for H. pylori infection. Amoxicillin concentrations in gastric mucosa and serum were quantitatively analysed in 12 patients with non-ulcer dyspepsia following the administration of one week duration of placebo as group I and omeprazole as group II. The study was a blind, cross-over design with a one week wash out period between the two treatment groups. Six antral gastric mucosa were biopsied 90 minutes after oral administration of amoxicillin. Blood samples were collected before and after administration at intervals up to 6 hours. All samples were analysed for amoxicillin concentration using the HPLC technique. Highly intersubject variations of amoxicillin concentrations were observed. The concentration of amoxicillin in gastric mucosa ranged from 0.00-1.74 and 0.00-1.25 micrograms/mg for group I and group II, respectively, with the mean concentration of 0.25 +/- 0.48 microgram/mg for group I and 0.28 +/- 0.40 microgram/mg for group II. The difference was not statistically significant (p = 0.89). Pharmacokinetic parameters of amoxicillin in serum following regimen I and regimen II were not significantly different (p > 0.05). The mean Cmax values were 14.62 +/- 5.39 and 12.65 +/- 4.76 micrograms/ml, the Tmax were 2.3 +/- 1.0 and 2.0 +/- 0.9 hour and the AUC0-6 were 40.79 +/- 13.26 and 38.75 +/- 15.04 micrograms/ml.h in the group I and group II, respectively. From these results, we concluded that omeprazole has no effect on gastric mucosa level nor serum levels of amoxicillin. The therapeutic efficacy of using these two agents in the eradication regimen of H. pylori may be related to other factors rather than pharmacokinetic interaction.
Subject(s)
Dyspepsia/drug therapy , Gastric Mucosa/drug effects , Helicobacter Infections/drug therapy , Helicobacter pylori/drug effects , Omeprazole/administration & dosage , Adult , Amoxicillin/administration & dosage , Amoxicillin/blood , Drug Interactions , Dyspepsia/microbiology , Enzyme Inhibitors/administration & dosage , Female , Humans , Male , Middle Aged , Penicillins/administration & dosage , Penicillins/blood , Probability , Reference ValuesABSTRACT
We compared a noninvasive serological test using a commercial immunoblot assay (Helicoblot 2.0) to tissue-based methods [rapid urease test (CLO test), histology and culture] in eighty Thai patients undergoing upper endoscopy. A true positive test was defined as at least two of the biopsy-related tests being positive. The CLO test was the most accurate test with sensitivity and specificity as high as 100%, whereas histology and culture had sensitivity of 100% and 72.2%, respectively, and the specificity of 72.7% and 96%, respectively. The serological test had a high sensitivity (97.2%) but exhibited an unsatisfactory specificity (40.9%). We concluded that the rapid urease test using multiple gastric biopsies was the most appropriate method for diagnosing H. pylori status. The role of immunoblot assay as a serological screening test in our population remains doubtful, but it may identify patients who have been infected with certain strains of H. pylori.
Subject(s)
Helicobacter Infections/diagnosis , Helicobacter Infections/immunology , Helicobacter pylori , Immunoblotting/methods , Adult , Aged , Aged, 80 and over , Antibodies, Bacterial/blood , Biopsy , Female , Helicobacter Infections/complications , Helicobacter Infections/enzymology , Helicobacter pylori/immunology , Helicobacter pylori/isolation & purification , Humans , Immunoblotting/statistics & numerical data , Male , Middle Aged , Sensitivity and Specificity , Serologic Tests , Stomach Ulcer/complications , Urease/analysisABSTRACT
BACKGROUND: The aim of this study was to assess the seroprevalence of cytotoxin-associated gene A (cagA) and vacuolating cytotoxin gene A (vacA) of Helicobacter pylori in selected Thai populations with specific gastroduodenal diseases. MATERIALS AND METHODS: The immunoblot assay was used to detect serum antibodies against CagA and VacA obtained from the following patients: 87 cases of nonulcer dyspepsia (NUD), 61 cases of duodenal ulcer (DU), 49 cases of gastric ulcer (GU), and 10 cases of gastric cancer (GC). RESULTS: Serum antibodies to CagA were detected in 75.4% of all patients (70. 1% of NUD, 78.7% of DU, 77.6% of GU, and 90% of GC). Although the prevalence of CagA seropositivity in GC patients was higher than in the other three groups, the difference was not statistically significant (p >.05). CONCLUSIONS: The high seroprevalence of the CagA-positive H. pylori strain in patients with peptic ulcer, GC, and NUD indicates that this strain is common in Thai patients with gastroduodenal diseases. Furthermore, phenotypic classification of H. pylori into type 1 (CagA-positive, VacA-positive) and type 2 (CagA-negative, VacA-negative) is not a useful marker for screening patients with severe forms of gastroduodenal diseases.
