Effects of Lansoprazole and Amoxicillin on Uptake of [ ¹⁴ C]Clarithromycin into Gastric Tissue in Rats

Abstract

Triple therapy consisting of clarithromycin (CLR), lansoprazole (LPZ), and amoxicillin (AMZ) is effective as eradication therapy for patients with peptic ulcer disease andThe association between active gastritis and Helicobacter pylori was first reported by Warren (24) and Marshall (13), and H. pylori-associated gastritis may be the cause of gastric ulcer. Recently, clinical trials involving the use of antibiotics yielded evidence that antibiotics can eradicate H. pylori (5,6,8,17).The macrolide antibiotic clarithromycin (CLR) is, to date, one of the most active antimicrobial agents against H. pylori in vitro (4). It is relatively stable in the presence of gastric acid (15) and has a high affinity for tissue (10). The penicillin antibiotic amoxicillin (AMZ) also has strong in vitro activity against H. pylori (7) and is more stable than macrolides in gastric acid. Treatment with CLR or AMZ alone in vivo, however, is rarely effective. The eradication rate was 15 to 54% when CLR was administered alone (18) and 20 to 30% when AMZ was administered alone (7). The activities of both CLR and AMZ against H. pylori are affected by pH, as the activities are reduced under acidic conditions (1, 4) and the levels of distribution of the drugs to the gastric mucus and mucosa inhabited by H. pylori are insufficient. When a single antibiotic, CLR or AMZ, was combined with a proton pump inhibitor (lansoprazole [LPZ]) (19), the eradication rates were 57 to 77% (20, 23). H. pylori was eradicated from 84 to 95% of patients concomitantly prescribed LPZ, CLR, and AMZ (2,11,20).To better comprehend the synergism, the effects of LPZ and AMZ on the distribution of 14 C-labeled CLR in rats were investigated, with particular focus on the ability of CLR to penetrate gastric tissue.

Helicobacter Pylori Eradication - A New Look at Old Problems

“…Fourthly, many doctors still believe that anti-helicobacter drugs act by absorbing them in the small intestine and creating high concentrations in the tissues of the stomach or after eckretsii in his lumen. However, a drug such as clarithromycin, originally developed for the treatment of pneumonia, has the highest concentrations in the tissues of the lungs, while in the tissues of the stomach their concentration is four times lower [20], and the excretion in the gland does not exceed 1% from the administered dose. It follows from this that the destruction of the infective can be achieved only by directly acting with bactericidal preparations inside the stomach over the entire surface of its mucosa.…”