Prevacid
One-week triple therapy with lansoprazole, clarithromycin, and metronidazole to cure Helicobacter pylori infection in peptic ulcer disease in Korea.

Perng CL, Kim JG, El-Zimaity HM, Osato MS, Graham DY.

Department of Medicine, Veterans Affairs Medical Center and Baylor College of Medicine, Houston, Texas 77030, USA.

The efficacy and acceptability of classical bismuth triple therapy may be limited by poor patient compliance and adverse effects. It is widely agreed that improved, simpler, and reliable therapies are needed to cure Helicobacter pylori infection and foster patient compliance. We evaluated the efficacy and side effects of a Bazzoli triple therapy substituting lansoprazole for omeprazole for H. pylori infection in active peptic ulcer in Korea (30 mg of lansoprazole, 250 mg of clarithromycin, and 400 mg of metronidazole, all twice daily). H. pylori status was evaluated by rapid urease test, histology, and culture at entry and four or more weeks after ending antimicrobial therapy. Fifty-eight patients (mean age: 43 years) with gastric (N = 30) or duodenal ulcer (N = 28) and H. pylori infection were studied. H. pylori was cured in 47 (81%, 95% CI = 69-90%). Mild side effects, including vomiting, diarrhea, and itching, were observed in four patients (7%). Compliance averaged 95%. Fifty-five ulcers (95%) were healed. Pretreatment pylorobulbar deformity was observed in 49 patients (85%), and in 43 (88%) the deformity disappeared after treatment. Pretreatment metronidazole and clarithromycin resistance was observed in 87% and 2% of patients, respectively. The cure rate of H. pylori infection was significantly higher in patients >50 years of age than those <50. Treatment with low-dose one-week lansoprazole, clarithromycin, and metronidazole resulted in a relatively low cure rate, but was well tolerated. Studies to define the optimal duration, dose, and dosing interval of this combination therapy in Korea are needed.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9539638&dopt=Abstract lansoprazole Prevacid



Prevacid
Growth inhibitory and bactericidal activities of lansoprazole compared with those of omeprazole and pantoprazole against Helicobacter pylori.

Nakao M, Malfertheiner P.

Pharmaceutical Research Laboratories III, Takeda Chemical Industries Ltd., Osaka, Japan.

BACKGROUND: Helicobacter pylori plays a role in the pathogenesis of both duodenal and gastric ulcers. The aim of this study was to evaluate the effect of the proton pump inhibitor (PPI), lansoprazole, commonly used in eradication regimens, on growth, bactericidal activity and morphology of H. pylori in vitro in comparison with other PPIs. MATERIALS AND METHODS: Growth inhibitory activity of each of the PPIs was evaluated by determining minimum inhibitory concentrations using an agar dilution method. Bactericidal activity was determined by analysis of the viable cells in culture at various time points after incubation with different concentrations of the PPIs. Bacterial morphology was examined using scanning electron microscopy of fixed cells after exposure to the test substances. Urease activity in cell extracts of H. pylori that had been incubated with increasing concentrations of the PPIs was determined by colorimetry. RESULTS: The growth inhibitory activity of lansoprazole was significantly more potent than that of omeprazole or pantoprazole (MIC90 6.25 vs. 25 and 100 micrograms/ml, respectively). Exposure of H. pylori to lansoprazole produced loss of viability and an aberrant bacterial morphology, which was more extensive than seen with omeprazole or pantoprazole. Lansoprazole dose dependently inhibited urease activity; its effectiveness was comparable with omeprazole but more potent than pantoprazole. CONCLUSIONS: The mechanism of action that leads to loss of viability of H. pylori cells appears to differ between the three PPIs investigated; lansoprazole was the most potent of the three agents in terms of growth inhibition and disruption of bacterial morphology.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9546114&dopt=Abstract lansoprazole Prevacid



Prevacid
Assessment of a new triple agent regimen for the eradication of Helicobacter pylori and the nature of H. pylori resistance to this therapy in Japan.

Suzuki J, Mine T, Kobayasi I, Fujita T.

Department of Internal Medicine IV, University of Tokyo School of Medicine, Japan.

BACKGROUND: Multiple regimens for the eradication of Helicobacter pylori have been tested, but the best therapy has not been determined yet. To determine the efficacy of a new triple agent regimen using a combination of lansoprazole, amoxicillin, and clarithromycin against Helicobacter pylori (H. pylori), and to examine H. pylori resistance to this therapy in ineffective cases. METHODS: We studied a total of 71 patients infected with H. pylori who had gastric ulcer (n = 37) or duodenal ulcer (n = 34) as confirmed by endoscopy. Patients received 1500 mg amoxicillin, 400 mg clarithromycin and 30 mg lansoprazole for 2 weeks followed by 30 mg lansoprazole for 6 weeks in patients with gastric ulcer or for 4 weeks in those with duodenal ulcer. Endoscopic examination was performed before treatment and at 1 month, 2 months, and 5 months after initiating treatment to check the status of ulceration and H. pylori infection. RESULTS: The eradication rate of H. pylori was 92% (CI, 83-100%) in the gastric ulcer group and 94% (CI, 86-100%) in the duodenal ulcer group at 5 months, as determined by per-protocol analysis. Resistance to clarithromycin was present in 1 of 71 (1%) patients before treatment and in 2 of 5 (40%) patients after treatment. No resistance to amoxicillin and lansoprazole was found in patients before or after treatment. The resistance to clarithromycin changed during the observation period. CONCLUSIONS: The new triple agent regimen was effective against H. pylori. Resistance to clarithromycin may not be permanent and it might be one of the risk factors which affect the efficacy of a clarithromycin-based therapy.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9546120&dopt=Abstract lansoprazole Prevacid



Prevacid
Synergic interactions of macrolides and proton-pump inhibitors against Helicobacter pylori: a comparative in-vitro study.

Malizia T, Tejada M, Marchetti F, Favini P, Pizzarelli G, Campa M, Senesi S.

Dipartimento di Biomedicina Sperimentale, Infettiva e Pubblica, Universita degli Studi di Pisa, Italy.

Thirty-eight clinical strains of Helicobacter pylori were isolated from patients with chronic gastritis and gastroduodenal ulceration, and their susceptibility to macrolide antibiotics (roxithromycin, flurithromycin, azithromycin, erythromycin) in combination with proton-pump inhibitors (lansoprazole and omeprazole) and bismuth subcitrate was assayed. Chequerboard titration was used to analyse the results of antimicrobial interactions and showed that the activity of macrolides was enhanced by combining them with lansoprazole, omeprazole or, to a lesser extent, bismuth subcitrate. While the interactions between erythromycin and the proton-pump inhibitors or bismuth subcitrate were always additive, the combinations of roxithromycin-lansoprazole, flurithromycin-omeprazole and azithromycin-lansoprazole acted synergically on 82%, 60% and 60% of H. pylori strains, respectively. These results may, in part, account for the enhanced clinical efficacy of macrolides administered with proton-pump inhibitors in the treatment of H. pylori-associated diseases.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9579710&dopt=Abstract lansoprazole Prevacid



Prevacid
[Sensitivity of Helicobacter pylori to amoxicillin and clarythromycin with special reference to eradication therapy]

[Article in Japanese]

Tsuneoka H, Takaba M, Nagatomi Y, Mori K, Matsumoto T, Honda T.

Department of Clinical Laboratory, Yamaguchi-ken Kouseiren Nagato General Hospital.

We isolated strains of Helicobacter pylori from gastric mucosa of patients with peptic ulcer before and after eradication therapy, and studied their sensitivity to amoxicillin (AMPC) and clarythromycin (CAM). Of 85 strains of H. pylori isolated before therapy, MIC90 was 0.025 microgram/ml and no strains were resistant to AMPC. On the other hand, MIC90 of CAM was 0.05 microgram/ml and seven (8.2%) were already resistant to CAM. The H. pylori strains from eight cases of failed eradication therapy with lansoprazole + AMPC remained AMPC sensitive. However H. pylori strains from nineteen cases (82.6%) out of 23 of failed eradication therapy with lansoprazole + CAM became CAM resistant. The situation was similar for the cases of failed eradication therapy with lansoprazole + AMPC + CAM. Drug sensitivity tests prior to eradication therapy are to be recommended. A disc method may be used as a simple alternative to MIC measurement.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9621560&dopt=Abstract lansoprazole Prevacid