Dual therapy versus triple therapy for Helicobacter pylori-associated duodenal ulcers

Polymorphisms and the Pocketbook: The Cost-Effectiveness of Cytochrome P450 2C19 Genotyping in the Eradication ofHelicobacter pyloriInfection Associated with Duodenal Ulcer

The clinical outcome of duodenal ulcer treated with proton pump inhibitor (PPI)-based, anti-Helicobacter pylori (H.p.) regimens varies according to cytochrome P450 2C19 (CYP2C19) genotype. CYP2C19 genotypes differ markedly in peoples of Pacific Rim descent compared with another ethnicity. The authors sought to determine the specific impact that these factors have on the cost-effectiveness of duodenal ulcer management. Their model consisted of two patient cohorts with Helicobacter pylori and duodenal ulcer, trichotomized into CYP2C19 homozygous extensive metabolizers (EMs), heterozygous EMs, and poor metabolizers (PMs), altering the anti-H.p. regimen in the genotyped cohort only. The authors took the perspective of a third-party payer, and the denominator was ulcer episode prevented. In the reference case, the use of CYP2C19 genotyping prior to initiating anti-H.p. therapy was dominant (costs were saved with each ulcer episode prevented) in all geographic regions of the United States. The subsequent break-even analysis showed a range of 89.20 dollars to 118.96 dollars--from Hawaii to the Midwest, respectively--required to eliminate the cost-savings from each genotype test performed. Using probabilities most unfavorable to genotyping, the variation of peoples with Pacific Rim origins from 0% to 100% altered the cost-effectiveness from 495 dollars to 2125 dollars per ulcer event prevented, respectively. The results suggest that treatment decisions for H.p. infection that are based on a patient's CYP2C19 genotype decreases expenses for health plans implementing testing. This analysis provides an economic basis to support recent calls to expand this technology into routine clinical care to prevent toxicity of narrow therapeutic index drugs.

Cost-effectiveness of Helicobacter pylori "test and treat" for patients with typical reflux symptoms in a population with a high prevalence of H. pylori infection: a Markov model analysis

OBJECTIVE

Patients with typical reflux symptoms may have underlying peptic ulcer disease (PUD) in a population with a high prevalence of Helicobacter pylori infection. In the present study we sought to compare the cost-effectiveness of the H. pylori "test and treat" strategy with that of empirical proton-pump inhibitor (PPI) therapy and endoscopy in patients with typical reflux and a high prevalence of H. pylori infection.

MATERIAL AND METHODS

A Markov model was designed to compare the outcomes of three treatment strategies over 12 months among a hypothetical cohort of patients presenting with typical reflux symptoms. There were four exclusive underlying H. pylori- and PUD-related comorbidities in the hypothetical cohort: (1) H. pylori-related PUD, (2) H. pylori infection without PUD, (3) PUD without H. pylori infection and (4) absence of both PUD and H. pylori infection. The transition probabilities and resource utilization were derived from the literature. Percentage of PUD patients treated, total number of symptom-free patient-years gained and total direct medical cost were estimated.

RESULTS

By comparing each strategy individually with the no therapy strategy, it was found that the incremental costs per ulcer treated for H. pylori "test and treat", endoscopy and empirical PPI therapy were USD 1778, USD 1797 and USD 2158, respectively. The results of the model were sensitive to the prevalence of H. pylori infection.

CONCLUSIONS

Both the H. pylori "test and treat" and initial endoscopic strategies were shown to be more cost-effective than empirical PPI therapy for treating undiagnosed PUD among patients presenting with typical reflux symptoms. The H. pylori "test and treat" strategy appeared to be only slightly more cost-effective than initial endoscopy in a population with a high prevalence of H. pylori infection.

In vitro susceptibility of Helicobacter pylori to isoquinoline alkaloids from Sanguinaria canadensis and Hydrastis canadensis

Methanol extracts of the rhizomes of Sanguinaria canadensis, and the roots and rhizomes of Hydrastis canadensis, two plants used traditionally for the treatment of gastrointestinal ailments, were screened for in vitro antibacterial activity against 15 strains of Helicobacter pylori. The rhizome extracts, as well as a methanol extract of S. canadensis suspension-cell cultures inhibited the growth of H. pylori in vitro, with a MIC50 range of 12.5-50.0 microg/ml. Three isoquinoline alkaloids were identified in the active fraction. Sanguinarine and chelerythrine, two benzophenanthridine alkaloids, inhibited the growth of the bacterium, with an MIC50 of 50.0 and 100.0 microg/ml, respectively. Protopine, a protopine alkaloid, also inhibited the growth of the bacterium, with a MIC50 of 100 microg/ml. The crude methanol extract of H. canadensis rhizomes was very active, with an MIC50 of 12.5 microg/ml. Two isoquinoline alkaloids, berberine and beta-hydrastine, were identified as the active constituents, and having an MIC50 of 12.5 and 100.0 microg/ml, respectively.

Sources of variation of Helicobacter pylori treatment success in adults worldwide: a meta-analysis

BACKGROUND

A vast number of Helicobacter pylori treatment trials have been conducted. Regimens may vary in efficacy in different patient populations.

METHODS

We identified sources of treatment effect variation from 618 treatment groups using weighted cross-classified multi-level meta-regression models. Summary effect estimates were calculated within groups that lacked identified heterogeneity.

RESULTS

Overall, treatment was less successful with shorter treatment duration and dual drug (versus triple or quadruple drug) therapies. For nitroimidazole-based regimens, treatment was less successful in populations with frequent childhood H. pylori infection or metronidazole resistance and more successful in northeastern Asia. Non-nitroimidazole treatments of longer duration and those from less recent reports were most successful. Some one-week regimens--(nitroimidazole/ tetracycline/bismuth, ranitidine bismuth citrate/amoxicillin/clarithromycin, and clarithromycin/amoxicillin/proton pump inhibitor) were highly successful in northeastern Asia regardless of metronidazole resistance. The most successful regimen in populations with both a high prevalence of metrondiazole resistance and frequent infection in children (metronidazole/furazolidone/amoxicillin) eliminated fewer than 70% of infections.

CONCLUSIONS

More effective treatments are needed for most populations of the world where H. pylori infection in children and drug resistance are common. Current treatment guidelines do not coincide with the best treatment regimens identified in this meta-analysis.

Economic analysis of four triple regimens for the treatment of Helicobacter pylori-related peptic ulcer disease in in-patient and out-patient settings in Hong Kong

BACKGROUND

One-week triple regimens have been shown to be effective for the treatment of Helicobacter pylori-related peptic ulcer disease.

AIM

To conduct an economic analysis of four triple regimens for the treatment of H. pylori-related peptic ulcer disease from the perspective of a public health organization in Hong Kong.

METHODS

Records of 200 patients with H. pylori-related peptic ulcer disease, who had previously participated in a randomized comparison of ranitidine bismuth citrate (RBC) with amoxicillin and clarithromycin (RAC), omeprazole with amoxicillin and clarithromycin (OAC), RBC with metronidazole and tetracycline (RMT), or, colloidal bismuth subcitrate with metronidazole and tetracycline (BMT) in either in-patient or out-patient setting were reviewed.

RESULTS

Fifty patients were excluded because of incomplete documentation or lack of peptic ulcer. In the out-patient group (n=72), the median direct costs of the RAC group (HK $ 5094) were lower those of the BMT (HK $ 5400), RMT (HK $ 5394), or OAC (HK $ 5440) groups, but the difference was significant only between the RAC and BMT groups (P < 0.05). In the in-patient group (n=78), the median direct costs of the RMT group (HK $ 8524) were significantly lower than those of the OAC (HK $ 13 871) and RAC (HK $ 12 092) groups (P < 0.05), but were similar to those of the BMT group (HK $ 8758).

CONCLUSIONS

RAC and RMT are the least costly regimens for out-patient and in-patient treatment, respectively, of H. pylori-related peptic ulcer disease in Hong Kong.

Pooled analysis of Helicobacter pylori eradication regimes in Asia

BACKGROUND AND AIMS

Differences in Helicobacter pylori strains and their resistance to antimicrobials between Asian and Western countries may affect the success in eradicating this bacterium. Our objective was to systematically review the regimens that have been tested in Asia.

METHODS

Data on anti-H. pylori therapies reported from Asia in a large number of publications identified up to December 1998 were pooled into a few groups based on the combination of drugs used. A comparison of different groups was made by calculating the pooled eradication rates.

RESULTS

Seventy-three studies with 134 treatment arms were reviewed. Pooled eradication rates of dual, triple and quadruple therapies were 61.0, 86.5 and 93.4%, respectively. Proton pump inhibitor (PPI)-based combinations were more widely used and effective, with overall eradication rates of 90.7% in triple therapy and 93.4% in quadruple therapy. Bismuth combined with tetracycline and metronidazole also showed a high eradication rate of 92.0%.

CONCLUSIONS

Proton pump inhibitor-based triple therapy with either clarithromycin, amoxycillin or metronidazole was one of the most commonly used and effective anti-H. pylori triple therapy regimens in Asia. The classical triple therapy with a bismuth, tetracycline and metronidazole combination has a similar efficacy. The results of anti-H. pylori treatment in Asia are not different from those in Western countries.

Observation and experiment on the cusp of collaboration: a parallel examination of clinical pharmacology and pharmacoepidemiology

Despite a common interest in the effect of drugs in humans, clinical pharmacologists and pharmacoepidemiologists often operate in isolation since the knowledge base underlying the respective parent disciplines of pharmacology and epidemiology is quite distinct. This lack of communication may lead to a potential for lost opportunities that would otherwise be mutually beneficial. Accordingly, this article juxtaposes the two disciplines to emphasize common areas of interest despite differences in methodology. In addition, weaknesses and strengths are contrasted in an effort to document the mirror image nature of both clinical pharmacology and pharmacoepidemiology in this regard. Specific examples underlying the complementary nature of the two disciplines are also offered that may help to stimulate collaboration. The possibility of greater formal cooperation between societies representing the two disciplines is also suggested to cross-educate both clinical pharmacologists and pharmacoepidemiologists as a means to foster collaboration.

Cure of Helicobacter pylori-positive active duodenal ulcer patients: a double-blind, multicentre, 12-month study comparing a two-week dual vs a one-week triple therapy. GISU (Interdisciplinary Group for Ulcer Study)

AIMS

To compare a two-week dual therapy to a one-week triple therapy for the healing of duodenal ulcer and the eradication of the Helicobacter pylori infection.

PATIENTS AND METHODS

A total of 165 patients with active duodenal ulcer were enrolled in the study. At entry, endoscopy, clinical examination and laboratory tests were performed. Histology and the rapid urease test were used to diagnose Helicobacter pylori infection. Patients received either lansoprazole 30 mg plus amoxycillin 1 g bid for two weeks (two-week, dual therapy) or lansoprazole 30 mg plus amoxycillin 1 g plus tinidazole 500 mg bid for one week plus lansoprazole qd for an additional week (one-week, triple therapy). Two and twelve months after cessation of therapy, endoscopy and clinical assessments were repeated.

RESULTS

Duodenal ulcer healing and Helicobacter pylori eradication were both significantly greater (p<0.0001) in the triple therapy group (healing: 98.6%; Helicobacter pylori cure rate: 72.6%) than in the dual therapy group (healing: 77.3%; Helicobacter pylori cure rate: 33.3%). Ulcers healed more frequently in Helicobacter pyloricured than in Helicobacter pylori-not cured patients (94.9% vs. 77.2%; p<0.0022). After one year, Helicobacter pylori eradication was re-confirmed in 46/58 patients previously treated with the triple therapy and in 10/40 patients treated with the dual therapy [p<0.0001]. Only three duodenal ulcer relapses were observed throughout follow-up: all were in Helicobacter pylori-not cured patients.

CONCLUSIONS

Triple therapy was more effective than dual both in curing Helicobacter pylori infection and healing active duodenal ulcers. The speed of ulcer healing obtained after only 7 days of antibiotics and 14 days of proton pump inhibitors confirmed that longer periods of anti ulcer therapy were not necessary. Helicobacter pylori -not cured patients had more slowly healing ulcers which were more apt to relapse when left untreated.

Spiramycin is comparable to oxytetracycline in eradicating H. pylori when given with ranitidine bismuth citrate and metronidazole

BACKGROUND

We have consistently achieved about 90% eradication of H. pylori with liquid bismuth, metronidazole and oxytetracycline.

AIM

To test eradication and adverse events of ranitidine bismuth citrate (RBC) when given with metronidazole and either oxytetracycline or spiramycin.

METHODS

One hundred and eighty-three patients were randomized to one of four 10-day regimens: RBC400OM: RBC 400 mg b.d., oxytetracycline 500 mg q.d.s.; RBC400SM: RBC 400 mg b.d., spiramycin 1 g q.d.s.; RBC200OM: RBC 200 mg q.d.s., oxytetracycline 500 mg q.d.s.; RBC200SM: RBC 200 mg q.d.s., spiramycin 1 g q.d.s. Additionally, all patients received metronidazole 400 mg q.d.s. A 14C-urea breath test was performed at 8 weeks.

RESULTS

Intention-to-treat eradication rates were 94%, 91%, 94% and 89% with RBC400OM, RBC400SM, RBC200OM and RBC200SM, respectively (P = 0.81). Eradication was significantly higher in ulcer patients (97%) than in those with diagnoses other than ulcer (86%) (P = 0.009). There was a strong tendency to better eradication among those who had never smoked (100%) compared with ex-smokers (93%) and smokers (89%) (P = 0.06). Fifty-three per cent experienced at least one moderate or severe adverse event, and women had more adverse events than men (P = 0.0002).

CONCLUSIONS

All four regimens had comparable efficacy and adverse events. Eradication was significantly better in ulcer patients but there was a trend to better eradication in those who smoked less, used less alcohol and exercised more. Adverse events were frequent, perhaps because of the large dose of metronidazole used, but few patients stopped treatment.

Discontinuation rates of Helicobacter pylori treatment regimens: a meta-analysis

We conducted a meta-analysis to determine what factors in treatment regimens for Helicobacter pylori are associated with increased discontinuation rates. Studies were selected from the 1990-1996 MEDLINE data base, and references in published articles and reviews were obtained. Each article was uniformally abstracted for factors that could potentially affect dropout rates. Drug regimens with high numbers of doses per day had highest dropout rates (p=0.0001). The total dropout rate was lowest for regimens containing a proton pump inhibitor (OR = 0.75, CI 0.57, 0.98). The rate was high in regimens containing a bismuth compound due to side effects (OR = 2.79, CI 1.78, 4.36). The main finding was that drug regimens for eradication of H. pylori that have a high number of doses per day result in higher discontinuation rates than regimens with fewer doses per day.

Omeprazole. A review of its use in Helicobacter pylori infection, gastro-oesophageal reflux disease and peptic ulcers induced by nonsteroidal anti-inflammatory drugs

Omeprazole is a well studied proton pump inhibitor that reduces gastric acid secretion. This review examines its use in Helicobacter pylori infection, gastro-oesophageal reflux disease (GORD) with or without oesophagitis and gastrointestinal damage caused by nonsteroidal anti-inflammatory drugs (NSAIDs). Optimal omeprazole regimens for anti-H. pylori therapy are those that administer the drug at a dosage of 40 mg/day (in 1 or 2 divided doses) for 7, 10 or 14 days in combination with 2 antibacterial agents. As a component of 3-drug regimens in direct comparative studies, omeprazole was at least as effective as lansoprazole, pantoprazole, bismuth compounds and ranitidine. However, a meta-analysis suggests that triple therapies with omeprazole are more effective than comparable regimens containing ranitidine, lansoprazole or bismuth. Omeprazole also appears to be successful in triple therapy regimens used in children with H. pylori infection. In patients with acute GORD with oesophagitis, omeprazole is at least as effective as lansoprazole or pantoprazole in promoting healing, and superior to ranitidine, cimetidine or cisapride in oesophagitis healing and symptom relief. Omeprazole was similar to lansoprazole and superior to ranitidine in preventing oesophagitis relapse in patients with all grades of oesophagitis, but may be superior to lansoprazole or pantoprazole in patients with more severe disease. More patients with symptomatic GORD without oesophagitis experienced symptom relief after short term treatment with omeprazole than with ranitidine, cisapride or placebo, and symptoms were more readily prevented by omeprazole than by cimetidine or placebo. Omeprazole was effective in healing and relieving symptoms of reflux oesophagitis in children with oesophagitis refractory to histamine H2 receptor antagonists. Omeprazole is superior to placebo in preventing NSAID-induced gastrointestinal damage in patients who must continue to take NSAIDs. It is also similar to misoprostol and superior to ranitidine in its ability to heal NSAID-induced peptic ulcers and erosions, and superior to misoprostol, ranitidine or placebo in its ability to prevent relapse. In long and short term studies, omeprazole was well tolerated, with diarrhoea, headache, dizziness, flatulence, abdominal pain and constipation being the most commonly reported adverse events. Usual omeprazole dosages, alone or combined with other agents, are 10 to 40 mg/day for adults and 10 to 20 mg/day for children.

CONCLUSIONS

Omeprazole is a well studied and well tolerated agent effective in adults or children as a component in regimens aimed at eradicating H. pylori infections or as monotherapy in the treatment and prophylaxis of GORD with or without oesophagitis or NSAID-induced gastrointestinal damage.

The impact of Helicobacter pylori eradication on peptic ulcer healing

OBJECTIVE

Current literature was reviewed analyzing the outcome of peptic ulcer healing in relation to the results of the posttherapeutic Helicobacter pylori (HP) status.

METHODS

Literature was reviewed along with an analysis of 60 studies, comprising a total of 4329 patients.

RESULTS

Successful Helicobacter pylori eradication was found to induce a better response in peptic ulcer healing, regardless of diagnosis: gastric ulcer 88% vs 73% (odds ratio [OR] 2.7, p < 0.01), duodenal ulcer 95% vs 76% (OR 5.6, p < 0.0001), and peptic ulcer 95% vs 76% (OR 6.6, p < 0.0001), for patients having their HP infection successfully cured versus those remaining HP-positive, respectively (Fisher's exact test). For all evaluated time points (< or = 6, 7-8, and 10-12 wk after beginning treatment), HP-negative patients had higher healing rates than HP-positive patients (95% vs 82%, 94% vs 69%, and 96% vs 78% with corresponding OR of 4.2, 6.5, and 7.4, all p < 0.0001, Fisher's exact test). The use of concomitant acid suppression therapy during initial HP eradication provided a benefit on peptic ulcer healing only for patients with persistent HP infection (improved healing rates of 78% vs 67%; otherwise rates were 94-96%). Likewise, prolonged acid inhibition in HP treatment failures after the initial HP treatment phase resulted in 7-20% improved healing rates, whereas patients becoming HP-negative did not profit.

CONCLUSION

Successful HP eradication therapy accelerates peptic ulcer healing even without concomitant acid suppression.

Doubling the omeprazole dose (40 mg b.d. vs. 20 mg b.d.) in dual therapy with amoxycillin increases the cure rate of Helicobacter pylori infection in duodenal ulcer patients

BACKGROUND

Several studies have shown that dual therapy with omeprazole and amoxycillin may cure Helicobacter pylori infection. However, the optimum dose of omeprazole has still to be established.

METHODS

An international, randomized, double-blind multicentre trial was conducted in patients with duodenal ulcers to compare the H. pylori cure rates obtained by dual therapy consisting of either omeprazole 20 mg b.d. plus amoxycillin 750 mg b.d. or omeprazole 40 mg b.d. plus amoxycillin 750 mg b.d. for 2 weeks. Dual therapy was followed by omeprazole 20 mg once daily for 2 weeks. Before entering the trial and 4 weeks after cessation of treatment H. pylori infection was assessed by histology and a 13C-urea breath test.

RESULTS

381 patients were randomized into the study, of whom 345 were evaluable for the all-patients-treated analysis of efficacy and 378 were valid for the evaluation of safety. Histology results showed that H. pylori infection was cured in 64 out 174 patients treated with omeprazole 20 mg b.d. plus amoxycillin and in 102 out of 171 patients treated with omeprazole 40 mg b.d. plus amoxycillin (37% vs. 60%; P < 0.001). Both treatment regimens were well tolerated, with adverse events reported by 29 (15.2%) and 35 patients (18.7%), respectively.

CONCLUSIONS

This study has shown that dual therapy with amoxycillin 750 mg b.d. and omeprazole 40 mg b.d. is superior to dual therapy with amoxycillin and omeprazole 20 mg b.d. in patients with H. pylori-positive duodenal ulcers. Thus, a true dose-response relationship exists between omeprazole and treatment success. However, a combination of omeprazole with two of amoxycillin, clarithromycin and nitroimidazole is a preferable alternative for routine clinical use.