Prevacid
Preformulation investigation of the novel proton pump inhibitor lansoprazole.

Kristl A, Vrecer F.

University of Ljubljana, Faculty of Pharmacy, Slovenia.

Some technologically important physicochemical properties of lansoprazole were investigated. This compound is very unstable, especially in aqueous solutions with low pH. It has one acidic and two basic dissociation constants. Lansoprazole has relatively high solubility in solutions with high pH and is well partitioned from aqueous to n-octanol phase. Under conditions examined in this study, lansoprazole was not hydroscopic and did not decompose at higher relative humidities.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10872099&dopt=Abstract lansoprazole Prevacid



Prevacid
Proton pump inhibitor therapy: preliminary results of a therapeutic interchange program.

Amidon PB, Jankovich R, Stoukides CA, Kaul AF.

Gastroenterology Section, Veteran's Administration Medical Center, Togus, ME 04330, USA.

OBJECTIVE: To analyze the experience of one Department of Veterans Affairs hospital in treating with lansoprazole all patients with acid-peptic disease requiring proton pump inhibitor therapy, including newly diagnosed patients and those who were previously stabilized on omeprazole. STUDY DESIGN: Retrospective analysis. PATIENTS AND METHODS: We evaluated the charts of 78 patients seen between March 17, 1997, and November 1998 by the Gastroenterology Section at the Togus Veterans Administration Hospital who were diagnosed with acid-peptic disease. RESULTS: Overall, side effects necessitated discontinuation of therapy in 10 (13%) of the lansoprazole-treated patients and none of the omeprazole-treated patients. Nine patients on lansoprazole suffered from persistent diarrhea and were placed on omeprazole, and one had lower back pain and was switched to cimetidine therapy. Additionally, 12 patients (15%) had their lansoprazole therapy discontinued because of lack of efficacy. Of the 78 lansoprazole-treated patients, 22 (28%) failed to respond to treatment. CONCLUSIONS: Although this study represents preliminary findings and the statistics are observational in nature, important lessons can be learned. At this particular institution, the potential 12% savings from a mandated therapeutic interchange program were quickly offset by the overall lansoprazole-associated failure rate of 28%. The reproducibility of these preliminary results from an omeprazole-to-lansoprazole therapeutic interchange program in other institutions is unknown but warrants further consideration and additional studies, including those evaluating cost efficacy.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10977467&dopt=Abstract lansoprazole Prevacid



Prevacid
Clinical and humanistic outcomes in patients with gastroesophageal reflux disease converted from omeprazole to lansoprazole.

Nelson WW, Vermeulen LC, Geurkink EA, Ehlert DA, Reichelderfer M.

Center for Drug Policy and Clinical Economics, University of Wisconsin Hospital and Clinics, 600 Highland Ave, 1530, CSC F6/133, Madison, WI 53792, USA. lc.vermeulen hosp.wisc.edu

BACKGROUND: Omeprazole and lansoprazole are 2 proton pump inhibitors (PPIs) currently available in the United States. Both PPIs are approved for the treatment of gastroesophageal reflux disease (GERD) and are commonly converted in therapeutic interchange programs. OBJECTIVE: To measure clinical and humanistic outcomes in patients with GERD converted from treatment with omeprazole to treatment with lansoprazole through a managed care plan policy. METHODS: Patients with heartburn or GERD receiving omeprazole covered by a local health plan were surveyed by telephone. Data collected included symptom frequency, severity, over-the-counter heartburn preparation use, diet, lifestyle, and overall satisfaction. Patients were then converted to therapy with lansoprazole and again interviewed after at least 30-day use of the new PPI. Demographic data were obtained from the health plan database for analysis. RESULTS: A total of 105 patients completed both telephone surveys. After the conversion, 37% of the patients experienced more frequent symptoms while awake. Symptom severity score was significantly higher (more severe) after conversion (mean score of 1.34 vs 2.26). Thirty-three percent of study patients consumed more over-the-counter heartburn preparations, and 13% changed their diet more frequently due to heartburn symptoms after conversion. Overall patient satisfaction score decreased significantly (less satisfied) after conversion (mean score of 9.0 vs 7.2). There were no significant differences in alcohol and tobacco consumption before and after conversion, while patients consumed significantly less caffeine after conversion. CONCLUSIONS: After the PPI therapeutic interchange from omeprazole to lansoprazole, patients with GERD or heartburn previously stabilized while receiving omeprazole experienced more severe symptoms and expressed decreased patient satisfaction. These results suggest a need to monitor symptoms after similar interchange programs.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10979061&dopt=Abstract lansoprazole Prevacid



Prevacid
The rates of common adverse events reported during treatment with proton pump inhibitors used in general practice in England: cohort studies.

Martin RM, Dunn NR, Freemantle S, Shakir S.

University of Bristol, Department of Social Medicine, Canynge Hall, Whiteladies Road, Bristol, UK. richard.martin bristol.ac.uk

AIMS: To estimate the rates of common adverse events in patients treated with the proton pump inhibitors omeprazole, lansoprazole and pantoprazole in general practice in England. METHODS: In prescription-event monitoring cohort studies, data on dispensed prescriptions prescribed by general practitioners in England soon after each drug was launched were linked to subsequent clinical events recorded by the prescriber. 16 205 patients prescribed omeprazole between June 1989 and June 1990, 17 329 patients prescribed lansoprazole between May and November 1994, and 11 541 patients prescribed pantoprazole between December 1996 and June 1997 were studied. RESULTS: The commonest adverse events in the omeprazole, lansoprazole and pantoprazole cohorts were diarrhoea (incidence: 0. 18, 0.39 and 0.23 per 1000 days of exposure, respectively); nausea/vomiting (incidence: 0.16, 0.22 and 0.18 per 1000 days of exposure, respectively); abdominal pain (incidence: 0.17, 0.21 and 0. 17 per 1000 days of exposure, respectively); and headache (incidence rates: 0.10, 0.17 and 0.15 per 1000 days of exposure, respectively). The remaining adverse events occurred at rates of less than 0.11 per 1000 days of exposure. There were little absolute differences in the rates of most events between the three proton pump inhibitors. However, diarrhoea was more commonly associated with lansoprazole compared with omeprazole (rate difference: 0.21 per 1000 days of exposure; 95% CI 0.17, 0.25; rate ratio: 2.11; 1.78, 2.51), and there was a clear age-response relationship. CONCLUSIONS: Adverse events occurred relatively infrequently in all three cohorts. There were only small absolute differences in event rates between the three drugs, although these data suggest the hypothesis that lansoprazole is associated with more frequent occurrence of diarrhoea, particularly in the elderly.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11012560&dopt=Abstract lansoprazole Prevacid



Prevacid
Helicobacter pylori effects on gastritis, gastrin and enterochromaffin-like cells in Zollinger-Ellison syndrome and non-Zollinger-Ellison syndrome acid hypersecretors treated long-term with lansoprazole.

Hirschowitz BI, Haber MM.

Division of Gastroenterology and Hepatology, The University of Alabama at Birmingham, 35294, USA. bhirschowitz gihep.uab.edu

BACKGROUND: Helicobacter pylori is said to cause atrophy of the gastric corpus and enterochromaffin-like cell proliferation in gastro-oesophageal reflux disease (GERD) patients treated long-term with a proton pump inhibitor. AIMS: To determine the effect of H. pylori infection on gastritis, enterochromaffin-like cell density and hyperplasia, mucosal atrophy and serum gastrin in patients with gastric hypersecretion (basal acid output gt; 15 mmol/h) with either hypergastrinemia (Zollinger-Ellison syndrome) or normal gastrin (non-Zollinger-Ellison syndrome) before and during long-term treatment with lansoprazole. METHODS: Lansoprazole was individually titrated to reduce basal acid output to < 5 mmol/h (< 1 mmol/h in post-surgical Zollinger-Ellison syndrome). Gastric corpus biopsies were obtained every 6 months before treatment and up to 8 years later. RESULTS: H. pylori was present in corpus biopsies in approximately 50%, causing active gastritis which resolved rapidly in 15 subjects after elimination of H. pylori. Patchy mild/moderate corpus atrophy was present at entry in two and at the end in four out of 60 patients, one being H. pylori-positive. Intestinal metaplasia (< 10%) was seen in six isolated biopsies (1% of total). H. pylori did not affect serum gastrin, enterochromaffin-like cell density or hyperplasia. Enterochromaffin-like cell density was twice as high in Zollinger-Ellison syndrome as in non-Zollinger-Ellison syndrome patients (241 vs. 126 cells/mm2, P < 0.001). Enterochromaffin-like cells remained normal in the non-Zollinger-Ellison syndrome hypersecretors regardless of H. pylori status. CONCLUSION: Corpus enterochromaffin-like cell increases were related to serum gastrin elevation, but neither H. pylori nor long-term treatment with lansoprazole alone or together had any effect on enterochromaffin-like cell density or hyperplasia. Corpus acute gastritis resulted from H. pylori infection, but did not result in mucosal atrophy despite long-term proton pump inhibitor treatment and promptly resolved with loss of H. pylori.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11136282&dopt=Abstract lansoprazole Prevacid