Lansoprazole. A reappraisal of its pharmacodynamic and pharmacokinetic properties, and its therapeutic efficacy in acid-related disorders

Prescription ranitidine use and population exposure in 6 Canadian provinces, 1996 to 2019: a serial cross-sectional analysis

BACKGROUND

Ranitidine was the most prescribed histamine-2 receptor antagonist (H2RA) in Canada when recalled in 2019 because of potential carcinogenicity. We sought to compare geographic and temporal patterns in use of prescription ranitidine and 3 other HRAs and estimated population exposure to ranitidine in 6 provinces between 1996 and 2019.

METHODS

This population-based serial cross-sectional study used prescription claims for H2RAs dispensed from community pharmacies in Nova Scotia, Ontario, Manitoba, Saskatchewan, Alberta and British Columbia. We estimated the period prevalence of ranitidine use per 100 population by province, age category and sex. We estimated exposure to ranitidine between 2015 and 2019 using defined daily doses (DDDs).

RESULTS

Overall, 2.4 million ranitidine prescriptions were dispensed to patients aged 65 years and older, and 1.7 million were dispensed to younger adults. Among older adults, the median period prevalence of ranitidine use among females was 16% (interquartile range [IQR] 13%-27%) higher than among males. Among younger adults, the median prevalence was 50% (IQR 37%-70%) higher among females. Among older adults, between 1996 and 1999, use was highest in Nova Scotia (33%) and Ontario (30%), lower in the prairies (Manitoba [18%], Saskatchewan [26%], Alberta [17%]) and lowest in BC (11%). By 2015-2019, use of ranitidine among older adults dropped by at least 50% in all provinces except BC. We estimate that at least 142 million DDDs of prescribed ranitidine were consumed annually in 6 provinces (2015-2019).

INTERPRETATION

Over the 24-year period in 6 provinces, patients aged 65 years and older were dispensed 2.4 million prescriptions of ranitidine and younger adults were dispensed 1.7 million prescriptions of ranitidine. These estimates of ranitidine exposure can be used for planning studies of cancer risk and identifying target populations for cancer surveillance.

Effects of caffeine, tea polyphenol and daidzein on the pharmacokinetics of lansoprazole and its metabolites in rats

abstract The aim of this study was to evaluate the effects of caffeine, tea polyphenol and daidzein on the pharmacokinetics of lansoprazole and its metabolites. Rats were intragastrically administered caffeine (30 mg·kg-1, once per day), tea polyphenol (400 mg·kg-1, once per day) or daidzein (13.5 mg·kg-1, once per day) for 14 days, followed by an intragastric administration of lansoprazole (8 mg·kg-1) on the 15th day. The plasma concentrations of lansoprazole and its two primary metabolites, 5-hydroxylansoprazole and lansoprazole sulfone, were determined by high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS). Tea polyphenol significantly elevated the Area Under the Curve (AUC) of lansoprazole from 680.29 ± 285.99 to 949.76 ± 155.18 μg/L.h and reduced that of lansoprazole sulfone from 268.82 ± 82.37 to 177.72 ± 29.73 μg/L.h. Daidzein increased the AUC of lansoprazole from 680.29 ± 285.99 to 1130.44 ± 97.6 μg/L.h and decreased that of lansoprazole sulfone from 268.82 ± 82.37 to 116.23 ± 40.14 μg/L.h. The pharmacokinetics of 5-hydroxylansoprazole remained intact in the presence of tea polyphenol or daidzein. Caffeine did not affect the pharmacokinetics of lansoprazole and its metabolites. The results imply that tea polyphenol and daidzein may inhibit the in vivo metabolism of lansoprazole by suppressing CYP3A.

Novel role of Zn(II)-curcumin in enhancing cell proliferation and adjusting proinflammatory cytokine-mediated oxidative damage of ethanol-induced acute gastric ulcers

Alcohol consumption can induce gastric ulcers and zinc deficiency. Zinc complexes were reported to have anti-ulcer activity as it acts as an anti-inflammatory and antioxidant. Zn(II)-curcumin complex and its solid dispersions (SDs) were synthesized and evaluated for its gastroprotective activity and mechanism against ethanol-induced ulcer. The Swiss murine fibroblast cell line (3T3) was used as an alternative in vitro model to evaluate the effects of Zn(II)-curcumin on cell proliferation. Zn(II)-curcumin were administered orally for seven consecutive days prior to induction of ulcers using ethanol. Gross and microscopic lesions, immunological and biochemical parameters were taken into consideration. The results showed that solid dispersions (SDs) of Zn(II)-curcumin (2.5-20 μM) enhanced the proliferation of 3T3 cells more significantly than curcumin at the same concentrations (P<0.01). Oral administration of Zn(II)-curcumin (12, 24 and 48 mg/kg) SDs dose-dependently prevented formation of ulcer lesions induced by ethanol. The levels of proinflammatory cytokines tumor necrosis factor-α (TNF-α), interleukin 6 (IL-6), and oxidative stress superoxide dismutase (SOD), glutathione peroxidase (GPX-Px), malonaldehyde (MDA) and H(+)-K(+)-ATPase were in the rats exposed to ethanol in ulceration have been altered. Zn(II)-curcumin prevented formation of ulcer lesions, significantly inhibited TNF-α and IL-6 mRNA expression, increased the activity of SOD and GSH-Px, reduced MDA levels and H(+)-K(+)-ATPase in mucosa of rats compared to controls (P<0.05). These findings suggest that the gastroprotective activity of Zn(II)-curcumin complex might contribute in stimulating cell proliferation and adjusting the proinflammatory cytokine-mediated oxidative damage to the gastric mucosa.

Ligand-based design of a potent and selective inhibitor of cytochrome P450 2C19

A series of omeprazole-based analogues was synthesized and assessed for inhibitory activity against CYP2C19. The data was used to build a CYP2C19 inhibition pharmacophore model for the series. The model was employed to design additional analogues with inhibitory potency against CYP2C19. Upon identifying inhibitors of CYP2C19, ligand-based design shifted to attenuating the rapid clearance observed for many of the inhibitors. While most analogues underwent metabolism on their aliphatic side chain, metabolite identification indicated that for analogues such as compound 30 which contain a heterocycle adjacent to the sulfur moiety, metabolism primarily occurred on the benzimidazole moiety. Compound 30 exhibited improved metabolic stability (Cl(int) = 12.4 mL/min/nmol) and was selective in regard to inhibition of CYP2C19-catalyzed (S)-mephenytoin hydroxylation in human liver microsomes. Finally, representative compounds were docked into a homology model of CYP2C19 in an effort to understand the enzyme-ligand interactions that may lead to favorable inhibition or metabolism properties.

Lansoprazole-induced improvement of esophageal submucosal injury

The proton pumpvinhibitor, lansoprazole, is reported to have acid secretion inhibiting effect as well as anti-inflammatory effects such as inhibition of cytokine secretion from inflammatory cells. Clinically, excellent efficacy of lansoprazole is reported for not only gastric ulcer but also gastroesophageal reflux disease (GERD). Since GERD is categorized endoscopically into erosive esophagitis and non-erosive reflux disease, it is important to make accurate assessment of any improvement in the inflammatory process when using endoscopic ultrasonography (EUS) capable of visualizing the submucosal structure. We report here our experience in assessing the effect of treatment with lansoprazole on esophageal wall structure using EUS in patients with GERD. At baseline (before treatment), EUS showed abnormalities in the mucosa, submucosa and muscularis propria caused by inflammation, thickening of the entire esophageal wall and changes in the contractile properties of esophageal smooth muscles reflecting the effects of inflammation on the entire wall of the lower esophagus in reflux esophagitis regardless of whether it is erosive or endoscopically-negative. Treatment with lansoprazole resulted in normalization of esophageal wall structure and improvement of motility, suggesting that lansoprazole improves not only mucosal inflammation but also submucosal inflammation in GERD.

Safety of the long-term use of proton pump inhibitors

The proton pump inhibitors (PPIs) as a class are remarkably safe and effective for persons with peptic ulcer disorders. Serious adverse events are extremely rare for PPIs, with case reports of interstitial nephritis with omeprazole, hepatitis with omeprazole and lansoprazole, and disputed visual disturbances with pantoprazole and omeprazole. PPI use is associated with the development of fundic gland polyps (FGP); stopping PPIs is associated with regression of FGP. In the absence of Helicobacter pylori infection, the long-term use of PPIs has not been convincingly proven to cause or be associated with the progression of pre-existing chronic gastritis or gastric atrophy or intestinal metaplasia. Mild/modest hypergastrinemia is a physiological response to the reduction in gastric acid secretion due to any cause. The long-term use of PPIs has not been convincingly proven to cause enterochromaffin-like cell hyperplasia or carcinoid tumors. PPIs increase the risk of community acquired pneumonia, but not of hospital acquired (nosocomial) pneumonia. There is no data to support particular care in prescribing PPI therapy due to concerns about risk of hip fracture with the long-term use of PPIs. Long-term use of PPIs does not lead to vitamin B12 deficiencies, except possibly in the elderly, or in persons with Zollinger-Ellison Syndrome who are on high doses of PPI for prolonged periods of time. There is no convincingly proven data that PPIs increase the risk of Clostridium difficile-associated diarrhea in persons in the community. The discontinuation of PPIs may result in rebound symptoms requiring further and even continuous PPI use for suppression of symptoms. As with all medications, the key is to use PPIs only when clearly indicated, and to reassess continued use so that long-term therapy is used judiciously. Thus, in summary, the PPIs are a safe class of medications to use long-term in persons in whom there is a clear need for the maintenance of extensive acid inhibition.

The role and limitations of H2-receptor antagonists in the treatment of gastro-oesophageal reflux disease

Gastro-oesophageal reflux disease (GERD) occurs in up to 44% of adults in the USA. Most individuals do not seek medical help, self-medicating with antacids. Manifestations of GERD range from symptoms without oesophagitis, which constitute the bulk of patients who self-medicate, to active oesophagitis and then to complications such as stricture and ulceration. It is the more severe cases who tend to come to the gastroenterologist, but it must be remembered that reflux symptoms are probably around 5-10 times more common than actual oesophagitis. Since acid in the refluxate is responsible for the bulk of the symptoms and mucosal damage, antacids are often used for quick relief--which of course may not be sustained. More prolonged suppression of acid secretion, such as by a histamine H2-receptor antagonist (H2RA) or a proton pump inhibitor (PPI), is required to give long-lasting symptomatic relief and heal any inflammatory change. H2-receptor antagonists inhibit acid secretion with an effect that lasts for 4-8 h with a single dose, decreasing stimulated acid secretion by around 70%. When treating oesophagitis, the H2RAs suffer from the disadvantage of their relatively short duration of action (compared with PPIs), development of tolerance, and incomplete inhibition of acid secretion in response to a meal. Therefore, it is not easy for the H2RAs to achieve optimum conditions for healing the more severe forms of oesophagitis--even very high doses may fail. In mild GERD the H2RAs have been shown to be effective in relieving symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of the proton pump inhibitor lansoprazole on the pharmacokinetics and pharmacodynamics of prasugrel and clopidogrel

Prasugrel and clopidogrel, thienopyridine prodrugs, are each metabolized to an active metabolite that inhibits the platelet P2Y(12) ADP receptor. In this open-label, 4-period crossover study, the effects of the proton pump inhibitor lansoprazole on the pharmacokinetics and pharmacodynamics of prasugrel and clopidogrel were assessed in healthy subjects given single doses of prasugrel 60 mg and clopidogrel 300 mg with and without concurrent lansoprazole 30 mg qd. C(max) and AUC(0-tlast) of prasugrel's active metabolite, R-138727, and clopidogrel's inactive carboxylic acid metabolite, SR26334, were assessed. Inhibition of platelet aggregation (IPA) was measured by turbidimetric aggregometry 4 to 24 hours after each treatment. Lansoprazole (1) decreased R-138727 AUC(0-tlast) and C(max) by 13% and 29%, respectively, but did not affect IPA after the prasugrel dose, and (2) did not affect SR62334 exposure but tended to lower IPA after a clopidogrel dose. A retrospective tertile analysis showed in subjects with high IPA after a clopidogrel dose alone that lansoprazole decreased IPA, whereas IPA was unaffected in these same subjects after a prasugrel dose. The overall data suggest that a prasugrel dose adjustment is not likely warranted in an individual taking prasugrel with a proton pump inhibitor such as lansoprazole.

Identification of a Single Time-point for Plasma Lansoprazole Measurement That Adequately Reflects Area Under the Concentration-Time Curve

The objective of this study was to identify a single time-point for plasma lansoprazole measurement that adequately reflects area under the plasma lansoprazole concentration-time curve (AUC) after administration of lansoprazole alone or together with coadministration with CYP mediators. A randomized double-blind placebo-controlled crossover study design in 3 phases was conducted at intervals of 2 weeks. Eighteen healthy Japanese volunteers, comprising 3 CYP2C19 genotype groups, took a single oral 60-mg dose of lansoprazole after three 6-day pretreatments, that is, clarithromycin 800 mg/d, fluvoxamine 50 mg/d, and placebo. Blood samplings (10 mL each) for determination of lansoprazole were taken up to 24 hours after the administration of lansoprazole. Correlation between plasma lansoprazole concentrations at various time points and AUC0-24 were analyzed. Although there were significant differences in the pharmacokinetic parameters of lansoprazole during clarithromycin and placebo among CYP2C19 genotypes, the differences were not found during fluvoxamine. The plasma concentrations 3, 4, 6, and 8 hours after administration (C3, C4, C6, and C8, respectively) were highly correlated with AUC0-24 in coadministration with placebo, clarithromycin, and fluvoxamine (r>0.8, P<0.001). In particular, C6 showed a correlation coefficient of 0.940, 0.992, and 0.953 in coadministration with placebo, clarithromycin, and fluvoxamine, respectively, and was the most appropriate for estimating AUC0-24. The present study demonstrates that AUC of lansoprazole can be estimated by using a single time-point at C6. This method of plasma concentration monitoring at one time-point might be more suitable for AUC estimation than reference to CYP2C19 genotypes, particularly in coadministration of CYP mediators.

Effects of D-002, a product isolated from beeswax, on gastric symptoms of patients with osteoarthritis treated with piroxicam: a pilot study

Non-steroidal anti-inflammatory drugs (NSAIDs) are indicated for treatment of rheumatoid arthritis and osteoarthritis, but often induce gastric adverse experiences (AE), including gastric ulcers and complications. Inhibitors of proton pump and H(2) antagonists are very effective for duodenal ulcer; meanwhile, cytoprotective drugs are more effective for gastric ulcer. D-002 is a mixture of higher aliphatic alcohols obtained from beeswax, wherein triacontanol is the most abundant. D-002 induces anti-ulcer effects through a cytoprotective mechanism, being more effective in protecting against ethanol- and NSAID-induced ulcers. The present double-blind, placebo-controlled clinical study was undertaken to investigate the effects of D-002 on gastric symptoms associated to piroxicam use on patients suffering osteoarthritis. Fifty-nine patients, all taking piroxicam, 20 mg/day, were randomized to placebo or D-002 (40 or 100 mg/day) for 14 days. The primary efficacy variable was the reduction on the frequency of patients with gastric AE compared with placebo. Pain evolution was investigated to discard any influence on D-002 on the analgesic effect of piroxicam. The frequency of patients treated with D-002, 40 and 100 mg/day, reporting acidity [0 of 18 (0%) and 1 of 21 (4.8%), respectively] was lower (P < .05) than in placebo [6 of 20 (30%)]. Also, the frequency of patients treated with 100 mg/day reporting some gastric AE [5 of 21 (23.8%)] was lower (P < .05) than in placebo [13 of 20 (65.0%)]. The analgesic effect of piroxicam was unaffected with D-002. Treatment was well tolerated. Two patients discontinued from the study because of gastrointestinal AE: one in the placebo group and the other treated with D-002, 40 mg/day. Other three patients discontinued because of other AE: mildly uncontrolled hypertension (one in the placebo group, one treated with D-002, 40 mg/day) and headache (one treated with D-200, 100 mg/day). It is concluded that D-002 could be useful for controlling gastric AE of patients treated with NSAIDs, although further studies with a larger sample size and longer follow-up are needed for definitive conclusions.

Pharmacokinetics of proton pump inhibitors in children

The use of proton pump inhibitors (PPIs) has become widespread in children and infants for the management of paediatric acid-related disease. Pharmacokinetic profiles of only omeprazole and lansoprazole have been well characterised in children over 2 years of age with acid-related diseases. Few data have been recently published regarding the pharmacokinetics of pantoprazole in children, and none are available for rabeprazole or esomeprazole. The metabolism of PPI enantiomers has never been studied in the paediatric population. A one-compartment model best describes the pharmacokinetic behaviour of omeprazole, lansoprazole and pantoprazole in children, with important interindividual variability for each pharmacokinetic parameter. Like adults, PPIs are rapidly absorbed in children following oral administration; the mean time to reach maximum plasma concentration varies from 1 to 3 hours. Since these agents are acid labile, their oral formulations consist of capsules containing enteric-coated granules. No liquid formulation is available for any of the PPIs. Thus, for those patients unable to swallow capsules, extemporaneous liquid preparations for omeprazole and lansoprazole have been reported; however, neither the absolute nor the relative bioavailabilities of these oral formulations have been studied in children. Intravenous formulations are available for omeprazole (in Europe), lansoprazole and pantoprazole. PPIs are rapidly metabolised in children, with short elimination half-lives of around 1 hour, similar to that reported for adults. All PPIs are extensively metabolised by the liver, primarily by cytochrome P450 (CYP) isoforms CYP2C19 and CYP3A4, to inactive metabolites, with little unchanged drug excreted in the urine. Similar to that seen in adults, the absolute bioavailability of omeprazole increases with repeated dosing in children; this phenomenon is thought to be due to a combination of decreased first-pass elimination and reduced systemic clearance. The apparent clearance (CL/F) of omeprazole, lansoprazole and pantoprazole appears to be faster for children than for adults. A higher metabolic capacity in children as well as differences in the extent of PPI bioavailability are most likely responsible for this finding. This may partly account for the need in children for variable and sometimes considerably greater doses of PPIs, on a per kilogram basis, than for adults to achieve similar plasma concentrations. Furthermore, no studies have been able to demonstrate a statistically significant correlation between age and pharmacokinetic parameters among children. Despite the small number of very young infants studied, there is some evidence for reduced PPI metabolism in newborns. The limited paediatric data regarding the impact of CYP2C19 genetic polymorphism on PPI metabolism are similar to those reported for adults, with poor metabolisers having 6- to 10-fold higher area under the concentration-time curve values compared with extensive metabolisers. Finally, because a pharmacokinetic/pharmacodynamic relationship exists for PPIs, the significant interindividual variability in their disposition may partly explain the wide range of therapeutic doses used in children. Further studies are needed to better define the pharmacokinetics of PPIs in children <2 years of age.

Effects of clarithromycin on lansoprazole pharmacokinetics between CYP2C19 genotypes

AIMS

Lansoprazole is a substrate of CYP2C19 and CYP3A. The aim of this study was to compare the inhibitory effects of clarithromycin, an inhibitor of CYP3A on the metabolism of lansoprazole between CYP2C19 genotypes.

METHODS

A two-way randomized double-blind, placebo-controlled crossover study was performed. Eighteen volunteers, of whom six were homozygous extensive metabolizers (EMs), six were heterozygous EMs and six were poor metabolizers (PMs) for CYP2C19, received two 6-day courses of either clarithromycin 800 mg or placebo daily in a randomized fashion with a single oral dose of lansoprazole 60 mg on day 6 in all cases. Plasma concentrations of lansoprazole and its metabolites, 5-hydroxylansoprazole and lansoprazole sulphone were monitored up to 24 h after dosing.

RESULTS

During placebo administration, the mean AUC0, infinity of lansoprazole in homozygous EMs, heterozygous EMs and PMs were 4652 (95% CI, 2294, 7009) ng ml(-1) h, 8299 (4784, 11814) ng ml(-1) h and 25293 (17643, 32943) ng ml(-1) h (P < 0.001), respectively. Clarithromycin treatment significantly increased Cmax by 1.47-fold, 1.71-fold and 1.52-fold and AUC0, infinity of lansoprazole by 1.55-fold, 1.74-fold, and 1.80-fold in these genotype groups, respectively, whereas elimination half-life was prolonged only in PMs. The clarithromycin-mediated percent increase in pharmacokinetic parameters such as Cmax, AUC0, infinity or elimination half-life did not differ between the three CYP2C19 genotypes.

CONCLUSIONS

The present study indicates that there are significant drug interactions between lansoprazole and clarithromycin in all CYP2C19 genotype groups probably through CYP3A inhibition. The bioavailability of lansoprazole might, to some extent, be increased through inhibition of P-glycoprotein during clarithromycin treatment.

Effect of water intake on pharmacokinetics of lansoprazole from fast disintegrating tablet in human subjects

Lansoprazole fast disintegrating tablet (LFDT) has been developed as a multiple unit formulation to increase the QOL of patients, i.e., easy intake without water. However, there is a possibility that patients intake LFDT in accordance with clarithromycin and amoxicillin with water. To study the effect of water on the absorption of lansoprazole (LPZ), the study was carried out using human volunteers. After selected by phenotype of LPZ metabolism, extensive metabolizers (EMs) of LPZ were used in this study. Twelve healthy male EMs intook LFDT containing 30 mg LPZ with 150 mL of water and without-water, i.e., with saliva, to study the pharmacokinetics of LPZ from the gastrointestinal tract by a cross-over manner with one-week washout period under fasted condition in the morning. The mean AUC(0-24s) were 2004.4+/-973.6 ng.h/mL in without-water experiment and 2018.5+/-1159.6 ng.h/mL in the case of with-water experiment. Mean C(maxs) were 851.9+/-450.8 ng/mL in without-water experiment and 830.8+/-456.8 ng/mL in with-water experiment, respectively. ANOVA was applied to the log-transformed AUC(0-24) and C(max) values. The 90% two sided confidence intervals for log-transformed AUC(0-24) was 0.78-1.22 and that for log-transformed C(max) was 0.67-1.37, respectively. By comparing these pharmacokinetic parameters, we may state that there was no significant difference between the two administration modes.

Effects of fluvoxamine on lansoprazole pharmacokinetics in relation to CYP2C19 genotypes

Lansoprazole is a substrate of CYP2C19 and CYP3A4. The aim of this study was to compare the inhibitory effects of fluvoxamine, an inhibitor of CYP2C19, on the metabolism of lansoprazole between CYP2C19 genotypes. Eighteen volunteers--of whom 6 were homozygous extensive metabolizers (EMs), 6 were heterozygous EMs, and 6 were poor metabolizers (PMs) for CYP2C19--received three 6-day courses of either daily 50 mg fluvoxamine or placebo in a randomized fashion with a single oral 60-mg dose of lansoprazole on day 6 in all cases. Plasma concentrations of lansoprazole and its metabolites, 5-hydroxylansoprazole and lansoprazole sulfone, were monitored up to 24 hours after the dosing. During placebo administration, there was a significant difference in the area under the plasma concentration-time curve from time 0 to infinity (AUC(0-infinity)) of lansoprazole between CYP2C19 genotypes. Fluvoxamine treatment increased AUC(0-infinity) of lansoprazole by 3.8-fold (P < .01) in homozygous EMs and by 2.5-fold (P < .05) in heterozygous EMs, whereas no difference in any pharmacokinetic parameters was found in PMs. There was a significant difference in the fluvoxamine-mediated percentage increase in the AUC(0-infinity) of lansoprazole between CYP2C19 genotypes. The present study indicates that there are significant drug interactions between lansoprazole and fluvoxamine in EMs. CYP2C19 is predominantly involved in lansoprazole metabolism in EMs.

Determination of lansoprazole in pharmaceutical capsules by flow injection analysis using UV-detection

The direct determination of lansoprazole by using a flow injection analysis (FIA) with UV-detection and its application to the pharmaceutical capsules is described, in this study. The best carrier solvent was found to be 0.01 M NaOH and it was determined at optimum conditions such as flow rate of 1 ml min(-1) and wavelength of 292 nm. Examining the repeatability of the method that was found to be 1.72% for intra-day and 2.13% for inter-day precision using the 8.01 x 10(-6) M lansoprazole concentration has validated the method. The linear range of the method was 5.4 x 10(-6) to 5.4 x 10(-5) M. The limit of detection and quantification was found to be 5.8 x 10(-7) and 1.7 x 10(-6) M, respectively. The proposed method was applied to the pharmaceutical capsules and very good results obtained. Thus, the FIA method for the quantification of lansoprazole can be proposed as a cheap, rapid, easy, accurate, and precise method for the routine determination in pharmaceutical preparations.

The Role of Proton Pump Inhibitors in Gastro-oesophageal Reflux Disease

The proton pump inhibitors (PPIs) are the most successful class of drugs that have been introduced for the treatment of gastro-oesophageal reflux disease (GORD) because of their profound and consistent effect on gastric acid secretion. The PPIs have demonstrated an excellent adverse effect profile after approximately 18 years of clinical use. Healing rates in erosive oesophagitis surpass 90%. Complete symptom resolution is achievable in close to 80% of patients with Barrett's oesophagus. Complications of these conditions, such as oesophageal stricture, ulceration and others, are becoming less frequent because of PPI treatment. In non-erosive reflux disease, PPIs provide 50-65% symptom response rate, which is the highest amongst all currently available anti-reflux interventions. PPIs have also helped to improve success rates in treating patients with atypical/extra-oesophageal manifestations of GORD. The use of PPI treatment as a diagnostic tool for GORD is well accepted. However, PPIs have changed the face of GORD in the new millennium as the focus in gastroenterology practice has shifted to primarily treating patients who fail PPI therapy.

Evaluation of Fast Disintegrating Lansoprazole Tablet in Human Subjects

Fast disintegrating lansoprazole tablet (LFDT) has been developed as a multiple unit formulation and evaluated using human subjects as compared to the conventional lansoprazole (LPZ) capsule containing enteric coated granules. Twelve healthy male volunteers, who were confirmed as extensive metabolizers (EMs) based on the plasma levels of LPZ sulphone metabolite, were enrolled into the study and genotype of CYP2C19 was confirmed. They kept 30 mg LFDT in their mouths for 2 min and the saliva was recovered without swallow. Eight subjects did not show LPZ in their serum after intake. Although LPZ was detected in 4 subjects' serum, their concentrations were less than 5 ng/mL. LPZ was thought to be not absorbed from the oral cavity. LFDT was orally administered to 12 healthy male EMs at two doses, 15 mg and 30 mg, and serum LPZ concentrations were measured. The mean C(max) and AUC(0-24) were 474.1+/-254.0 ng/mL and 1105.3+/-1101.4 ng.h/mL (15 mg) and 992.8+/-384.3 ng/mL and 2216.5+/-1270.1 ng.h/mL (30 mg). By comparing to that obtained after oral administration of the same doses of LPZ capsule, serum LPZ concentration vs. time curve was almost the same level, i.e., C(max) and AUC(0-24) did not have significant differences. From these results, LFDT has been shown to be equivalent to LPZ capsule and will show the same acid suppressing effects in the clinical situation.

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

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.

Gastroesophageal reflux in children: pathogenesis, prevalence, diagnosis, and role of proton pump inhibitors in treatment

A substantial percentage of infants, children and adolescents experience gastroesophageal reflux disease (GERD) and its accompanying symptoms, as well as disease complications. The diagnosis of GERD in children is made based upon the child's history, and data derived primarily from pH monitoring tests and endoscopy. In those children with confirmed reflux disease, the options for management parallel those recommended in adult patients, with the first step consisting of lifestyle changes. Surgical procedures may also be performed; however, these are rarely recommended prior to an adequate course of pharmacologic therapy, and appropriate case selection is important. Among the current pharmacotherapeutic options available in the US, the prokinetic agents and the acid-inhibitory agents (histamine-2 receptor antagonists, proton pump inhibitors) are the most widely used. The clinical utility of the prokinetic agents has been limited by the recent withdrawal of cisapride from the US marketplace and the potential for irreversible central nervous system complications with metoclopramide. Numerous clinical studies performed in adults, and several studies involving children, have demonstrated that the proton pump inhibitors are more effective than the histamine-2 receptor antagonists in the relief of GERD symptoms and healing of erosive esophagitis. In children, omeprazole and lansoprazole may be administered as the intact oral capsule, or in those who are unable or unwilling to swallow, the granule contents of the capsule may be mixed with soft foods (e.g. apple sauce) or fruit drinks/liquid dietary supplements prior to oral administration with no detrimental effects on pharmacokinetics, bioavailability, or pharmacodynamics. Studies performed with omeprazole and lansoprazole in children have shown pharmacokinetic parameters that closely resemble those observed in adults. In over a decade of use in adults, the proton pump inhibitor class of agents has been found to have a good safety profile. Studies involving children have also shown these agents to be well tolerated. In numerous drug-drug interaction studies performed with these two proton pump inhibitors, relatively few clinically significant interactions have been observed.

Esomeprazole: a review of its use in the management of acid-related disorders

Esomeprazole (S-isomer of omeprazole), the first single optical isomer proton pump inhibitor, generally provides better acid control than current racemic proton pump inhibitors and has a favourable pharmacokinetic profile relative to omeprazole. In a large well designed 8-week trial in patients (n >5000) with erosive oesophagitis, esomeprazole recipients achieved significantly higher rates of endoscopically confirmed healed oesophagitis than those receiving lansoprazole. Respective healed oesophagitis rates with once-daily esomeprazole 40mg or lansoprazole 30mg were 92.6 and 88.8%. Overall, esomeprazole was also better than omeprazole, although these differences were not always statistically significance. Ninety-two to 94% of esomeprazole recipients (40mg once daily) achieved healed oesophagitis versus 84 to 90% of omeprazole recipients (20mg once daily). Esomeprazole was effective across all baseline grades of oesophagitis; notably, relative to lansoprazole, as baseline severity of disease increased, the difference in rates of healed oesophagitis also increased in favour of esomeprazole. Resolution of heartburn was also significantly better with esomeprazole 40mg than with these racemic proton pump inhibitors. Long-term (up to 12 months) therapy with esomeprazole effectively maintained healing in these patients. Once-daily esomeprazole 20 or 40mg for 4 weeks resolved symptoms in patients with symptomatic gastro-oesophageal reflux disease (GORD) without oesophagitis. Symptoms were effectively managed in the long-term with symptom-driven on-demand esomeprazole (20 or 40mg once daily). Eradicating Helicobacter pylori infection is considered pivotal to successfully managing duodenal ulcer disease. Seven days' treatment (twice-daily esomeprazole 20mg plus amoxicillin 1g and clarithromycin 500mg) eradicated H. pylori in >/=86% of patients (intention-to-treat), a rate that was similar to equivalent omeprazole-based regimens. Esomeprazole is generally well tolerated, both as monotherapy and in combination with antimicrobial agents, with a tolerability profile similar to that of other proton pump inhibitors. Few patients discontinued therapy because of treatment-emergent adverse events (<3% of patients), with very few (<1%) drug-related serious adverse events reported.

CONCLUSIONS

Esomeprazole is an effective, well tolerated treatment for managing GORD and for eradicating H. pylori infection in patients with duodenal ulcer disease. In 8-week double-blind trials, esomeprazole healed oesophagitis and resolved symptoms in patients with endoscopically confirmed erosive oesophagitis and overall, provided better efficacy than omeprazole. Notably, in a large (n >5000 patients) double-blind trial, esomeprazole 40mg provided significantly better efficacy than lansoprazole in terms of healing rates and resolution of symptoms. Long-term therapy with esomeprazole maintained healed oesophagitis in these patients. Esomeprazole also proved beneficial in patients with symptomatic GORD without oesophagitis. Thus, esomeprazole has emerged as an option for first-line therapy in the management of acid-related disorders.

Esomeprazole: a review of its use in the management of acid-related disorders in the US

Esomeprazole, the S-isomer of omeprazole, is the first proton pump inhibitor to be developed as a single optical isomer. It provides better acid control than current racemic proton pump inhibitors and has a favourable pharmacokinetic profile relative to omeprazole. In large well designed 8-week trials in patients with erosive oesophagitis, esomeprazole recipients achieved significantly higher rates of endoscopically confirmed healed oesophagitis than those receiving omeprazole or lansoprazole. Esomeprazole was effective across all baseline grades of oesophagitis; notably, relative to lansoprazole, as the baseline severity of disease increased, the difference in rates of healed oesophagitis also increased in favour of esomeprazole. In two trials, 94% of patients receiving esomeprazole 40mg once daily achieved healed oesophagitis versus 84 to 87% of omeprazole recipients (20mg once daily). In a study in >5000 patients, respective healed oesophagitis rates with once-daily esomeprazole 40mg or lansoprazole 30mg were 92.6 and 88.8%. Resolution of heartburn was also significantly better with esomeprazole than with these racemic proton pump inhibitors. Long-term (up to 12 months) therapy with esomeprazole effectively maintained healed oesophagitis in these patients. Esomeprazole 20 or 40mg once daily for 4 weeks proved effective in patients with symptomatic gastro-oesophageal reflux disease (GORD) without oesophagitis. Eradicating Helicobacter pylori infection is considered pivotal to successfully managing duodenal ulcer disease. Ten days' triple therapy (esomeprazole 40mg once daily, plus twice-daily amoxicillin 1g and clarithromycin 500mg) eradicated H. pylori in 77 to 78% of patients (intention-to-treat) with endoscopically confirmed duodenal ulcer disease. Esomeprazole is generally well tolerated, both as monotherapy and in combination with antimicrobial agents. The tolerability profile is similar to that of other proton pump inhibitors. Few patients discontinued therapy because of treatment-emergent adverse events (<3% of patients) and very few (<1%) drug-related serious adverse events were reported.

CONCLUSIONS

Esomeprazole is an effective and well tolerated treatment for managing GORD and for eradicating H. pylori infection in patients with duodenal ulcer disease. In 8-week double-blind trials, esomeprazole effectively healed oesophagitis and resolved symptoms in patients with endoscopically confirmed erosive oesophagitis. Notably, in large (n >1900 patients) double-blind trials, esomeprazole provided significantly better efficacy than omeprazole or lansoprazole in terms of both healing rates and resolution of symptoms. Long-term therapy with esomeprazole effectively maintained healed oesophagitis in these patients. Esomeprazole was also effective in patients with symptomatic GORD. Thus, esomeprazole has emerged as an effective option for first-line therapy in the management of acid-related disorders.

Lansoprazole: an update of its place in the management of acid-related disorders

Lansoprazole is an inhibitor of gastric acid secretion and also exhibits antibacterial activity against Helicobacter pylori in vitro. Current therapy for peptic ulcer disease focuses on the eradication of H. pylori infection with maintenance therapy indicated in those patients who are not cured of H. pylori and those with ulcers resistant to healing. Lansoprazole 30 mg combined with amoxicillin 1g, clarithromycin 250 or 500mg, or metronidazole 400 mg twice daily was associated with eradication rates ranging from 71 to 94%, and ulcer healing rates were generally >80% in well designed studies. In addition, it was as effective as omeprazole- or rabeprazole-based regimens which included these antimicrobial agents. Maintenance therapy with lansoprazole 30 mg/day was significantly more effective than either placebo or ranitidine in preventing ulcer relapse. Importantly, preliminary data suggest that lansoprazole-based eradication therapy is effective in children and the elderly. In the short-term treatment of patients with gastro-oesophageal reflux disease (GORD), lansoprazole 15, 30 or 60 mg/day was significantly more effective than placebo, ranitidine 300 mg/day or cisapride 40 mg/day and similar in efficacy to pantoprazole 40 mg/day in terms of healing of oesophagitis. Lansoprazole 30 mg/day, omeprazole 20 mg/day and pantoprazole 40 mg/day all provided similar symptom relief in these patients. In patients with healed oesophagitis. 12-month maintenance therapy with lansoprazole 15 or 30 mg/day prevented recurrence and was similar to or more effective than omeprazole 10 or 20 mg/day. Available data in patients with NSAID-related disorders or acid-related dyspepsia suggest that lansoprazole is effective in these patients in terms of the prevention of NSAID-related gastrointestinal complications, ulcer healing and symptom relief. Meta-analytic data and postmarketing surveillance in >30,000 patients indicate that lansoprazole is well tolerated both as monotherapy and in combination with antimicrobial agents. After lansoprazole monotherapy commonly reported adverse events included dose-dependent diarrhoea, nausea/vomiting, headache and abdominal pain. After short-term treatment in patients with peptic ulcer, GORD, dyspepsia and gastritis the incidence of adverse events associated with lansoprazole was generally < or = 5%. Similar adverse events were seen in long-term trials, although the incidence was generally higher (< or = 10%). When lansoprazole was administered in combination with amoxicillin, clarithromycin or metronidazole adverse events included diarrhoea, headache and taste disturbance. In conclusion, lansoprazole-based triple therapy is an effective treatment option for the eradication of H. pylori infection in patients with peptic ulcer disease. Preliminary data suggest it may have an important role in the management of this infection in children and the elderly. In the short-term management of GORD, lansoprazole monotherapy offers a more effective alternative to histamine H2-receptor antagonists and initial data indicate that it is an effective short-term treatment option in children and adolescents. In adults lansoprazole maintenance therapy is also an established treatment option for the long-term management of this chronic disease. Lansoprazole has a role in the treatment and prevention of NSAID-related ulcers and the treatment of acid-related dyspepsia; however, further studies are needed to confirm its place in these indications. Lansoprazole has emerged as a useful and well tolerated treatment option in the management of acid-related disorders.

Bioequivalence evaluation of lansoprazole 30-mg capsules (Lanfast and Lanzor) in healthy volunteers

The bioequivalence of two lansoprazole 30-mg capsules was determined in healthy human, adult volunteers after a single dose in a randomized cross-over study. The study was conducted at Pharmaconsult, Flemington Pharmaceutical Corp., New Jersey, USA. Reference (Lanzor, Laboratoires Houde, Paris, France) and test (Lanfast, Julphar, UAE) were administered to volunteers with 240 ml water after overnight fasting. Blood samples were collected at specified time intervals, plasma was separated and analyzed for lansoprazole using a validated HPLC method. The pharmacokinetic parameters AUC(0-t), AUC(0-~), C(max), T(max), T(1/2) and elimination rate constant were determined from plasma concentration-time profile of both formulations and found to be in good agreement with previously reported values. The calculated pharmacokinetic parameters were compared statistically to evaluate bioequivalence between the two brands, using the statistical modules recommended by the Food and Drug Administration. The analysis of variance (ANOVA) did not show any significant difference between the two formulations and 90% confidence intervals fell within the acceptable range (80-120%) for bioequivalence. Based on these statistical inferences it was concluded that the two formulations exhibited comparable pharmacokinetic profiles and that Julphar's Lanfast is bioequivalent to Lanzor of Lab. Houde.

Lansoprazole in the treatment of gastro-oesophageal reflux disease in childhood

BACKGROUND

Acid suppressive therapy is the mainstay of pharmacologic treatment of gastro-oesophageal reflux disease. Use of proton pump inhibitors in children is still limited and has only included omeprazole in a few controlled studies.

AIM

To determine efficacy of lansoprazole, a relatively new proton pump inhibitor, on symptoms and oesophagitis in a group of children with gastro-oesophageal reflux disease refractory to H2 receptor antagonists. The required dose of the drug for inhibiting gastric acidity was also determined.

PATIENTS AND METHODS

A series of 35 children (median age: 7.6 years, range: 3-15) with oesophagitis refractory to H2 receptor antagonists received a 12-week therapeutic course with lansoprazole. Prior to the study children underwent symptomatic and endoscopic assessment, oesophageal manometry and 24-hour intragastric and intra-oesophageal pH test. The latter was repeated after one week of therapy while patients were on treatment in order to monitor the degree of acid suppression and adjust the dose of the drug. Symptomatic assessment and endoscopy were repeated at the end of the trial

RESULTS AND CONCLUSIONS

In 12 patients (group A), the initial dose of the drug was efficacious (1.3 to 1.5 mg/kg/day), whereas in 23 [group B) the initial dose (0.8 to 1.0 mg/kg/day) was increased by half because of insufficient inhibition of intragastric acidity (i.e., when the intra-gastric pH remained below 4.0 for more than 50% of the recording time). Nine patients in group A (75%) and 8 in group B (53.5%) healed (chi2: 3.6, p<0.05); 1 patient in group A [8.3%) and 7 in group B (30.5%) remained unchanged (chi2: 6.9, p<0.01); 2 patients in group A and 8 in group B improved and underwent a further month of therapy. The two groups did not differ as far as concerns baseline pH, endoscopic and clinical variables. In both groups, those patients failing to respond at the end of the trial showed a more impaired oesophageal motility than improved or healed patients. The drug was well tolerated and no significant laboratory abnormalities occurred. In children with gastro-oesophageal reflux disease refractory to H2 receptor antagonists, a 12-week course of lansoprazole is effective both in healing oesophagitis and improving symptoms. An initial dose of 1.5 mg/kg/day of the drug is suggested. However, if during treatment, patients remain symptomatic the dose should be increased and a prolonged intra-gastric and intra-oesophageal pH test performed to evaluate the acid suppression efficacy of the adjusted dose. A short course of lansoprazole appears to be safe and well tolerated in paediatric age.

Review article: comparison of the pharmacokinetics, acid suppression and efficacy of proton pump inhibitors

Proton pump inhibitors have dramatically influenced the management of acid-peptic disorders in recent years. They all have a broadly similar mechanism of action and are extensively metabolized in the liver via cytochromes P450 2C19 and 3A4. There is some variation in their potential for drug interactions due to differences in enzyme inhibition. Relatively few serious adverse effects have been reported for the proton pump inhibitors. Comparative studies of acid suppression suggest that lansoprazole and pantoprazole have a potency similar to that of omeprazole on a mg for mg basis; however, rabeprazole may have a greater potency than omeprazole. Lansoprazole and rabeprazole display a more rapid onset of maximal acid suppression than the other proton pump inhibitors. Comparative studies using proton pump inhibitors for the treatment of reflux oesophagitis, duodenal ulcer healing and Helicobacter pylori eradication show little overall difference in outcome between the proton pump inhibitors when used in their standard doses. Lansoprazole and rabeprazole provide earlier and better symptom relief than the other proton pump inhibitors in some studies of peptic ulcer treatment. The few studies of gastric ulcer treatment suggest that there is an advantage in using the proton pump inhibitors that have a higher standard daily dose.

Oral pharmacokinetics of omeprazole and lansoprazole after single and repeated doses as intact capsules or as suspensions in sodium bicarbonate

BACKGROUND

Omeprazole and lansoprazole can be given in sodium bicarbonate as, respectively, simplified omeprazole suspension and simplified lansoprazole suspension. We previously found the antisecretory effect of omeprazole 20 mg given as simplified omeprazole suspension to be lower than with intact capsules. However, lansoprazole 30 mg as simplified lansoprazole suspension produced an effect similar to that seen with intact capsules.

AIM

To evaluate the absorption of both drugs when given orally as capsules or as suspensions in sodium bicarbonate.

METHODS

In random order, we gave 5-day courses of omeprazole 20 mg and lansoprazole 30 mg as capsules and as suspensions in sodium bicarbonate to 12 healthy women. Serial blood samples were taken on days 1 and 5 of each course for pharmacokinetic measurements.

RESULTS

There was impairment of omeprazole absorption when given as simplified omeprazole suspension. Maximum plasma concentration and area under the concentration/time curve were lower with simplified omeprazole suspension than with omeprazole capsules (P=0.034 and 0.013, respectively, on day 5). No differences were found in lansoprazole absorption when simplified lansoprazole suspension was compared with its standard capsule formulation. Relative bioavailability of omeprazole from simplified omeprazole suspension compared to the capsule was 58.4% on day 5. The corresponding value for lansoprazole was 84.7%.

CONCLUSIONS

Simplified omeprazole suspension 20 mg does not supply adequate omeprazole for systemic absorption. Lansoprazole absorption from simplified lansoprazole suspension is maintained.

Pharmacokinetic considerations in the eradication of Helicobacter pylori

As Helicobacter pylori plays an important role in the aetiopathogenesis of peptic ulcer, therapeutic strategies aimed at maintaining long term remission have shifted from the control of intragastric pH to targeting H. pylori. According to recent international guidelines the clinical goals--rapid ulcer healing and prevention of relapse--can be best accomplished by combination therapy consisting of an antisecretory drug (proton pump inhibitor or ranitidine) and 2 antimicrobial agents (preferable amoxicillin, clarithromycin or metronidazole). When applying such multidrug regimens, possible synergy between the agents suggests that pharmacokinetic considerations might help to improve H. pylori eradication rates, which should be above 85 to 90% on an intention-to-treat basis. The present review summarises the pharmacokinetic properties and interaction potential of all drugs presently used in the various H. pylori eradication regimens, with emphasis on particular patient populations such as the elderly and those with renal impairment. The drugs considered are omeprazole, lansoprazole, pantoprazole, rabeprazole, ranitidine and ranitidine bismutrex, bismuth salts, amoxicillin, clarithromycin, azithromycin, roxithromycin, metronidazole, tinidazole and tetracycline. When addressing the clinically important questions of the efficacy, safety and costs of the recommended regimens, the impact of drug disposition on H. pylori eradication should not be neglected.

Ultrasonographic evaluation of lansoprazole-induced improvement of submucosal injury in patients with gastroesophageal reflux

OBJECTIVE

Endoscopic ultrasonographic (EUS) changes in gastroesophageal reflux disease (GERD) after treatment with proton pump inhibitor have been poorly evaluated. We conducted a randomized, double-blind 12-wk clinical trial to compare the EUS effects of lansoprazole to histamine H2-receptor antagonist therapy in GERD.

METHODS

Seventeen patients with reflux-related symptoms received 40 mg of famotidine for 6 wk or 30 mg of lansoprazole for 6 wk followed by 40 mg of famotidine or 30 mg of lansoprazole for another 6 wk, respectively. Patients underwent EUS before and at 6 and 12 wk after treatment.

RESULTS

Before treatment, a variable degree of wall thickening was noted on EUS in the lower esophagus, compared with 20 normal subjects. After 6 wk of therapy, esophageal wall was significantly thicker in the famotidine group compared with the lansoprazole group (p<0.01). Surprisingly, thickening of esophageal wall and abnormal architecture were also detected in endoscopically negative reflux disease. Lansoprazole was superior to famotidine in reducing the thickness of esophageal wall.

CONCLUSIONS

EUS was very useful for evaluation of submucosal injury in patients with GERD. EUS showed that a 6-wk course of lansoprazole therapy reduced thickening of esophageal wall, which was resistant to histamine H2-receptor antagonist therapy. Our results also suggest that inflammatory damage to the submucosal and muscle layers of the lower esophagus is the underlying mechanism of heartburn and associated symptoms in patients with endoscopically negative reflux disease.

Lack of pharmacokinetic interaction between lansoprazole and intravenously administered phenytoin

The objective of this randomized, double-blind, two-period crossover study was to investigate whether concomitant steady-state lansoprazole influences the pharmacokinetics of CYP2C9 substrates using single intravenously dosed phenytoin as a model substrate. In addition, the safety of concomitant administration of these two drugs was evaluated. Twelve healthy, nonsmoking, adult male subjects received 60 mg lansoprazole or placebo once daily for 9 days during each study period. On the morning of day 7, each subject received a single 250 mg intravenous phenytoin dose. There were no statistically significant differences between the two regimens for mean phenytoin Cmax or tmax. There was a minor (< 3%) but statistically significant difference between the two regimens for phenytoin AUC resulting from a very low intrasubject coefficient of variation (2.3%). The treatment and control mean plasma concentration phenytoin profiles were virtually super-imposable. In conclusion, concomitant multidose lansoprazole administration is unlikely to have any clinically significant effect on the pharmacokinetics of CYP2C9 substrates in general or intravenous phenytoin specifically.

Standard-dose lansoprazole is more effective than high-dose ranitidine in achieving endoscopic healing and symptom relief in patients with moderately severe reflux oesophagitis. The Dutch Lansoprazole Study Group

BACKGROUND

In the treatment of reflux oesophagitis, H2-receptor antagonists are still widely used in spite of the apparent higher efficacy of proton pump inhibitors. In an attempt to compensate for the lower efficacy, H2-receptor antagonists are now increasingly being used at a higher dose.

OBJECTIVE

To assess whether or not standard-dose lansoprazole (30 mg o.d.) is more effective than high-dose ranitidine (300 mg b.d.) in moderately severe reflux oesophagitis (grades II-III).

METHODS

Lansoprazole or ranitidine was given to 133 patients for 4-8 weeks in a double-blind, randomized, parallel group, multicentre trial.

RESULTS

The percentage of patients with endoscopically-verified healing was significantly higher on lansoprazole than on ranitidine both after 4 weeks (79% vs. 42%) and 8 weeks (91% vs. 66%), though smoking had a negative impact on oesophagitis healing with lansoprazole. Heartburn, retrosternal pain and belching improved significantly better with lansoprazole than with ranitidine, as did the patient-rated overall symptom severity. Relief of heartburn appeared somewhat faster with ranitidine, but was more pronounced with lansoprazole. The number of patients with adverse events was similar in both treatment groups.

CONCLUSION

Standard-dose lansoprazole is better than high-dose ranitidine in moderately severe reflux oesophagitis.

Determination of Lansoprazole in pharmaceutical dosage forms by two different spectroscopic methods

Two different ultraviolet (UV) spectroscopic methods were developed for determination of Lansoprazole in pharmaceutical dosage forms. The solutions of the standard and the sample were prepared in 0.1 M NaOH and phosphate buffer pH 6.6. Both UV spectrophotometric and derivative spectroscopic techniques were applied. Second-order derivative spectra were generated between 200 and 400 nm at N = 9, deltalambda = 31.5. The linear range for the UV spectrophotometric method was 3.0-25.0 microg ml(-1) and that for the derivative spectroscopic method was 0.5-25.0 microg ml(-1). The developed methods were applied to three different pharmaceutical preparations. The percentage recovery was 100.2%.

Pharmacokinetic interaction between acetaminophen and lansoprazole

Because of its minimal gastric toxicity, acetaminophen is the analgesic of choice for patients with gastric acid-related disorders. Because proton pump inhibitors are widely used, concomitant prescription of acetaminophen and lansoprazole would be prevalent. This crossover study was conducted to investigate an acetaminophen-lansoprazole interaction. On one occasion, each of six healthy, fasted, male volunteers ingested 1.0 g acetaminophen dissolved in 200 mL water. On another occasion, at least 1 week apart, 30 mg lansoprazole was administered orally, simultaneously with acetaminophen, after pretreatment with the same dose of lansoprazole once daily for 2 days. Plasma acetaminophen concentrations were measured at 0, 0.25, 0.5, 0.75, 1, 2, 3, 5, and 8 hours after dosing. The peak plasma concentration of acetaminophen and the time to its occurrence were significantly higher and shorter, respectively, during the lansoprazole session than during the control session. Neither the elimination half-life nor the area under the curve was significantly different between the two sessions. Lansoprazole hastens the absorption of acetaminophen solution, but little modifies its elimination rate and bioavailability.

A practical approach to patients with refractory Helicobacter pylori infection, or who are re-infected after standard therapy

The vast majority of recurrences of Helicobacter pylori infection after apparent eradication are observed during the first year. Almost all of these early recurrences are due to recrudescence rather than reinfection by a new strain. After the first year, the recurrence rates approximate to the rate of natural acquisition of H. pylori infection. By contrast, in developing countries, higher rates of recurrence suggest a major role of real reinfection. Important predictive factors of H. pylori treatment success are compliance and bacterial susceptibility to antibiotics. The new 1-week triple therapies, based on a proton pump inhibitor (PPI) and 2 antibiotics, lead to treatment discontinuation but rarely. If containing a nitroimidazole, their efficacy is reduced to 60 to 80% by pretreatment in vitro resistance. The prevalence of nitroimidazole resistance varies dependent on the geographical area, with rates over 50% in tropical regions. Resistance against macrolides hinders treatment success in 50 to 80% of patients. In the US, south-western Europe and Japan the prevalence of macrolide resistance amounts to about 10%, in other countries about 3%. After failed treatment, acquired resistance is frequent. Testing for resistance is recommended to facilitate the decision for an alternative triple therapy or for quadruple therapy comprising bismuth, metronidazole, tetracycline and a PPI. It seems reasonable to increase the dose of PPI in a retreatment regimen containing amoxicillin. Post-treatment double resistance against nitroimidazoles and macrolides reduces the success of most of the currently evaluated retreatment regimens. To overcome double resistance, high dose PPI plus amoxicillin is one approach, beside other experimental multidrug treatments.

Effect of omeprazole, lansoprazole, and ranitidine on the DNA synthesis of mononuclear cells

OBJECTIVE

To examine and compare the effects of omeprazole, lansoprazole, and ranitidine on the DNA synthesis of peripheral blood mononuclear cells.

DESIGN

Ex vivo laboratory study.

SETTING

Clinical research laboratory of an academic medical center.

SUBJECTS

Healthy volunteers.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Venous blood was collected from normal subjects and peripheral blood mononuclear cells (PBMCs) were isolated using centrifugation techniques over a Ficoll-Hypaque density gradient. PBMCs were added to 12-well culture plates in four groups of media: a) control; b) control plus lansoprazole (25 microg/mL); c) control plus omeprazole (0.35 microg/mL); and d) control plus ranitidine (50 microg/mL). PBMCs were exposed to the drug for 96 hrs, with addition of phytohemagglutinin (2.5 microg/ mL) for the last 48 hrs, and 3H-thymidine (1 microCi) during the final 6 hrs. PBMCs were filtered onto glass-fiber filter paper and the radioactivity was determined by scintillation counting. Since radioactivity is measured only in those cells undergoing DNA synthesis or cell division, results are expressed as quantification of 3H-thymidine uptake. Median disintegrations per min (DPM)/number of PBMCs per well+/-SEM are reported: control 68.3+/-37.8; ranitidine 38.4 +/-94.2; lansoprazole 14.6+/-84.4; and omeprazole 15.1+/-48.9. There was a significant difference between lansoprazole vs. ranitidine (p< .01), and omeprazole vs. ranitidine (p< .05), and no significant difference between lansoprazole and omeprazole.

CONCLUSIONS

This is the first study to compare the potential immunomodulating effects of these commonly used agents. Ranitidine caused increased DNA synthesis in PBMCs when compared with lansoprazole and omeprazole. This phenomenon may be an important, often disregarded, effect of histamine-2-receptor antagonists when used in postsurgical or trauma patients who have T-lymphocyte-mediated immune suppression.