Prevacid
Anodic voltammetric assay of lansoprazole and omeprazole on a carbon paste electrode.

Radi A.

Department of Chemistry, Faculty of Science, Mansoura University, 34517 Dumyat, Egypt. abdradi yahoo.com

The electrochemical oxidations of lansoprazole and omeprazole have been studied at a carbon paste electrode by cyclic and differential-pulse voltammetry in Britton-Robinson buffer solutions (0.04 M; pH 6.0-10.0). The drug produced a single oxidation step. By differential-pulse voltammetry, a linear response was obtained in B-R buffer pH 6.0 in a concentration range from 2.0 x 10(-7) to 5.0 x 10(-5) M for lansoprazole or omeprazole. The detection limits were 1.0 x 10(-8) and 2.5 x 10(-8) M for lansoprazole and omeprazole, respectively. The method was successfully applied for the analysis of omeprazole and lansoprazole in capsules. The results were comparable to those obtained by spectrophotometry. Copyright 2003 Elsevier Science B.V.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12684113&dopt=Abstract lansoprazole Prevacid



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A summary of Food and Drug Administration-reported adverse events and drug interactions occurring during therapy with omeprazole, lansoprazole and pantoprazole.

Labenz J, Petersen KU, Rosch W, Koelz HR.

Department of Medicine, Jung-Stilling Hospital, Siegen, Germany. J.Labenz t-online.de

BACKGROUND: Pantoprazole is claimed to have a lower potential for drug interaction than other proton pump inhibitors. AIM: To estimate the frequency of adverse events and drug interactions reported to the Food and Drug Administration in patients receiving omeprazole, lansoprazole or pantoprazole. METHODS: The study involved a search of the Food and Drug Administration's database for adverse events and drug interactions with omeprazole, lansoprazole or pantoprazole as primary or secondary suspect drug. An estimate of the amount of drug dispensed during the adverse event collection period (from US drug launch) was obtained from the International Medical Statistics health database. RESULTS: Of the suspected drug interactions recorded, vitamin K antagonist interactions, although rare, were the most common. The frequency of vitamin K antagonist interactions was 0.09 per million packages for omeprazole and 0.11 per million packages for lansoprazole and pantoprazole. Interactions with benzodiazepines or phenytoin were even rarer, being reported in less than 10 patients on each proton pump inhibitor. CONCLUSION: The frequency of reported drug interactions was low for omeprazole, lansoprazole and pantoprazole and vitamin K antagonist interactions were by far the most common. These potentially important drug interactions, although rare, were no less frequent on pantoprazole than on omeprazole or lansoprazole, suggesting a class effect.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12694083&dopt=Abstract lansoprazole Prevacid



Prevacid
Lansoprazole overutilization: methods for step-down therapy.

Pohland CJ, Scavnicky SA, Lasky SS, Good CB.

Veterans Affairs Pittsburgh Healthcare System, Pittsburgh, Penn 15240, USA.

OBJECTIVE: To identify the documented indications for long-term therapy with lansoprazole 30 mg twice daily at the Veterans Affairs Pittsburgh Healthcare System, assess compliance with appropriate use criteria, evaluate patients eligible for step-down therapy, and recommend appropriate step-down therapy in order to improve patient care, decrease overprescribing, and reduce medication costs. STUDY DESIGN: Prospective intervention. METHODS: The records of all patients with prescriptions for lansoprazole 30 mg twice daily as of June 2000 were reviewed. Patients were interviewed to assess medication compliance and symptom control and to provide education on lifestyle modifications. Interventions with the providers were completed to encourage step-down therapy in appropriate patients. RESULTS: Two hundred forty-eight patients with active prescriptions for twice-daily lansoprazole were reviewed. Of these patients, 66% (n = 163) did not have an indication compliant with the medical center's guidelines for use of lansoprazole 30 mg twice daily. Of these, 88% (n = 143) had no documented attempt at step-down therapy and 49% (n = 80) had no documented gastrointestinal workup. Interventions for step-down therapy were recommended for 48% (n = 120) of the 248 patients. Forty-six percent (n = 60) of recommendations were accepted, resulting in a cost savings of dollars 85000 per year. CONCLUSIONS: A high rate of clinician noncompliance with the guidelines for appropriate use of lansoprazole 30 mg twice daily was found. These prescribing patterns resulted in significant cost concerns. Our review and interventions led to step-down therapy for almost half of the patients receiving twice-daily lansoprazole. This review of patient records and intervention with primary care providers resulted in cost reduction and offered an opportunity to educate patients on beneficial lifestyle modifications.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12744297&dopt=Abstract lansoprazole Prevacid



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Localization of [14C]amoxicillin in rat gastric tissue when administered with lansoprazole and clarithromycin.

Endo H, Yoshida H, Ohmi N, Ohta K, Higuchi S.

Department of Drug Metabolism, Research Center, Taisho Pharmaceutical Co., Ltd, 403 Yoshino-cho 1-chome, Saitama-shi, Saitama 330-8530, Japan. hiromi.endou po.rd.taisho.co.jp

The gastric mucosal distribution of [14C]amoxicillin when administered to rats with or without lansoprazole and clarithromycin was investigated. After oral administration, the amount found in the gastric mucosa was higher than after iv administration. Co-administration of lansoprazole and clarithromycin had no apparent effect on the distribution pattern of [14C]amoxicillin within the deeper stomach layers. About 50-60% of the radioactivity in the gastric tissue was present in the mucosal layer, irrespective of the route of administration. Microautoradiograms of the gastric mucosa indicated that [14C]amoxicillin was distributed in both the mucous layer and surface epithelial cells following oral administration. [14C]amoxicillin was secreted mainly by surface epithelial cells after iv administration, although only in small quantities.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11733481&dopt=Abstract lansoprazole Prevacid



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Formulation study for lansoprazole fast-disintegrating tablet. I. Effect of compression on dissolution behavior.

Shimizu T, Nakano Y, Morimoto S, Tabata T, Hamaguchi N, Igari Y.

Pharmaceutical Development Laboratories, Pharmaceutical Production Division, Takeda Chemical Industries, Ltd. Shimizu_Toshihiro takeda.co.jp

Lansoprazole fast-disintegrating tablet (LFDT) is a new patient-friendly formulation of lansoprazole. Since lansoprazole is an antiulcer agent and is unstable under acidic conditions, we have developed LFDT as an orally disintegrating tablet containing enteric-coated microgranules. The effect of compression on dissolution behavior was investigated, as compression affected cleavage and crushing of the enteric layer. To decrease cleavage and crushing of the enteric layer, the effects of the combined ratio of methacrylic acid copolymer dispersion to ethyl acrylate-methyl methacrylate copolymer dispersion and the concentration of triethyl citrate on the dissolution in the acid stage and the dissolution in the buffer stage were evaluated. By adjusting the ratio of methacrylic acid copolymer dispersion to ethyl acrylate-methyl methacrylate copolymer dispersion to 9 : 1 and adding a 20% triethyl citrate concentration, sufficient flexibility of the enteric layer and sufficient stability against compression forces were achieved. Agglomeration of enteric-coated microgranules during the coating process was decreased at the optimized concentration of triethyl citrate and glyceryl monostearate. We compared the absorption properties of LFDT and lansoprazole capsules in dogs. The absorption profiles of LFDT were similar to those of lansoprazole capsules.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12913232&dopt=Abstract lansoprazole Prevacid