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At least 19 recordsLinked to original sources

PubMed2004

A pharmacokinetic study comparing single and repeated oral doses of 20 mg and 40 mg omeprazole and its two optical isomers, S-omeprazole (esomeprazole) and R-omeprazole, in healthy subjects.

OBJECTIVE: To investigate the pharmacokinetics of S-omeprazole (esomeprazole), R-omeprazole and racemic omeprazole following single and repeated oral doses of 20 mg and 40 mg of each compound in healthy male and female subjects. METHODS: In an open, randomised, three-way, cross-over study, 12 subjects received 20 mg and another 12 subjects received 40 mg S-omeprazole, R-omeprazole and racemic omeprazole as oral solutions once daily for 5 days, separated by washout periods of at least 10 days. Blood samples were taken for analysis pre-dose and at selected time points during a 12-h period following drug administration on study day 1 and day 5. Pharmacokinetic parameters of S-omeprazole, R-omeprazole, racemic omeprazole and the two main metabolites (5-hydroxy and sulphone) were calculated using non-compartmental analysis. RESULTS: Following the 20-mg dose of each compound, values of the total area under the plasma concentration-time curve (AUC) were 1.52, 0.62 and 1.04 micromol h/l for S-omeprazole, R-omeprazole and racemic omeprazole, respectively, on day 1. Respectively, AUC values on day 5 were 2.84, 0.68 and 1.63 micromol h/l. Corresponding values after the 40-mg doses were 3.88, 1.39 and 2.44 micromol h/l on day 1 and 9.32, 1.80 and 5.79 micromol h/l on day 5. CONCLUSION: Treatment with S-omeprazole (esomeprazole; 20 mg and 40 mg) resulted in higher AUC values than with either R-omeprazole or racemic omeprazole after both single and repeated doses due to a lower metabolic rate of S-omeprazole than R-omeprazole and, consequently, racemic omeprazole. S-Omeprazole, R-omeprazole and the racemate were well tolerated.

Administration, Oral↗

PubMed2006

Acid-suppressive effects of generic omeprazole: comparison of three brands of generic omeprazole with original omeprazole.

BACKGROUND: Generic omeprazole contains the same active ingredient as original omeprazole and require verification of the bioequivalence with original omeprazole. However, very few clinical studies have been reported. AIMS: A prospective, randomised, open-label, crossover study to compare acid-suppressive effect of generic omeprazole with that of original omeprazole. SUBJECTS: Seven healthy Helicobacter pylori-negative subjects of CYP2C19 extensive metaboliser. METHODS: Intragastric pH was measured for 24 h without medications (placebo) and on day 7 of repeated administration of 10 mg once daily after breakfast of original omeprazole, Omeprazon, or three brands of generic omeprazole, Omeprazole-Towa, Ovulanze or Omerap. RESULTS: Median values of intragastric pH and percentages of time with pH>4 for 24 h were significantly higher with administration of any omeprazole formulation compared with placebo (P<0.05, Wilcoxon signed-rank test). Whereas, during the night-time period (20:00-08:00 h), percentages of time with pH>4 with Omeprazole-Towa and Omerap were not significantly higher than placebo. Compared with Omeprazon, these two parameters for 24 h showed significantly greater inter-subject variations with Omeprazole-Towa (P<0.05 and P<0.01, F-test) and Ovulanze (P<0.05). CONCLUSIONS: Acid-suppressive effects of some brands of generic omeprazole are not the same as original omeprazole. These differences might be reflected in clinical outcomes.

Adult↗

PubMed2002

A double-blind, randomized comparison of omeprazole Multiple Unit Pellet System (MUPS) 20 mg, lansoprazole 30 mg and pantoprazole 40 mg in symptomatic reflux oesophagitis followed by 3 months of omeprazole MUPS maintenance treatment: a Dutch multicentre trial.

BACKGROUND: Proton pump inhibitors (PPIs) have proved to be effective in treating reflux oesophagitis. Until now, no study had compared the PPIs omeprazole Multiple Unit Pellet System (MUPS), lansoprazole and pantoprazole in patients with reflux oesophagitis. AIM: To compare omeprazole MUPS 20 mg, lansoprazole 30 mg and pantoprazole 40 mg for treatment effect in symptomatic reflux oesophagitis. METHOD: Patients with grade I-IV symptomatic reflux oesophagitis were randomized to double-blind omeprazole 20 mg once morning, lansoprazole 30 mg o.m. or pantoprazole 40 mg o.m. Patient satisfaction and symptoms were evaluated after 4 and 8 weeks. Patients not satisfied after 8 weeks were treated for another 4 weeks with omeprazole 40 mg MUPS (open). Successful treatment was followed by 3 months' maintenance treatment with omeprazole MUPS 20 mg (patients satisfied after 4 or 8 weeks) or omeprazole MUPS 40 mg (patients satisfied after 12 weeks). RESULTS: On intention-to-treat (ITT) analysis (n = 461) at 4 and 8 weeks, respectively, 84% and 87% (omeprazole MUPS), 78% and 81% (lansoprazole), and 84% and 89% (pantoprazole) were free of heartburn. Equivalence was found between omeprazole MUPS and pantoprazole (heartburn relief), but not with lansoprazole. Patient satisfaction after 4 and 8 weeks, respectively, was 79% and 89% (omeprazole MUPS), 76% and 86% (lansoprazole), and 79% and 91% (pantoprazole). Patient satisfaction was similar in all treatment groups. During maintenance, 87% in the omeprazole MUPS 20 mg group and 81% in the omeprazole MUPS 40 mg group were satisfied after 3 months. CONCLUSIONS: Omeprazole MUPS 20 mg and pantoprazole 40 mg have equivalent efficacy in the treatment of reflux oesophagitis. Based on patient satisfaction, omeprazole MUPS 20 mg, lansoprazole 30 mg and pantoprazole 40 mg are equally effective.

2-Pyridinylmethylsulfinylbenzimidazoles↗

PubMed1998

Omeprazole compared with misoprostol for ulcers associated with nonsteroidal antiinflammatory drugs. Omeprazole versus Misoprostol for NSAID-induced Ulcer Management (OMNIUM) Study Group.

BACKGROUND: Misoprostol is effective for ulcers associated with the use of nonsteroidal antiinflammatory drugs (NSAIDs) but is often poorly tolerated because of diarrhea and abdominal pain. We compared the efficacy of omeprazole and misoprostol in healing and preventing ulcers associated with NSAIDs. METHODS: In a double-blind study, we randomly assigned 935 patients who required continuous NSAID therapy and who had ulcers or more than 10 erosions in the stomach or duodenum (or both) to receive 20 mg or 40 mg of omeprazole orally in the morning or 200 microg of misoprostol orally four times daily. Patients were treated for four weeks or, in the absence of healing, eight weeks. Treatment success was defined as the absence of ulcers and the presence of fewer than five erosions at each site and not more than mild dyspepsia. We then randomly reassigned 732 patients in whom treatment was successful to maintenance therapy with 20 mg of omeprazole daily, 200 microg of misoprostol twice daily, or placebo for six months. RESULTS: At eight weeks, treatment was successful in 76 percent of the patients given 20 mg of omeprazole (233 of 308), 75 percent of those given 40 mg of omeprazole (237 of 315), and 71 percent of those given misoprostol (212 of 298). The rates of gastric-ulcer healing were significantly higher with 20 mg of omeprazole (but not 40 mg of omeprazole) than with misoprostol. Healing rates among patients with duodenal ulcers were higher with either dose of omeprazole than with misoprostol, whereas healing rates among patients with erosions alone were higher with misoprostol. More patients remained in remission during maintenance treatment with omeprazole (61 percent) than with misoprostol (48 percent, P=0.001) and with either drug than with placebo (27 percent, P<0.001). There were more adverse events during the healing phase in the misoprostol group than in the groups given 20 mg and 40 mg of omeprazole (59 percent, 48 percent, and 46 percent, respectively). CONCLUSIONS: The overall rates of successful treatment of ulcers, erosions, and symptoms associated with NSAIDs were similar for the two doses of omeprazole and misoprostol. Maintenance therapy with omeprazole was associated with a lower rate of relapse than misoprostol. Omeprazole was better tolerated than misoprostol.

Adult↗

PubMed1995

Twenty-four-hour intragastric acidity: 300 mg ranitidine b.d., 20 mg omeprazole o.m., 40 mg omeprazole o.m. vs. placebo.

BACKGROUND: There is considerable controversy about the degree of acid suppression that is optimal for the treatment of peptic disorders. AIM: To compare the effects of three different regimens that are reported to strongly inhibit acid secretion. METHODS: Intragastric 24-hour pH monitoring was performed in 11 healthy subjects in a randomized, multiple, cross-over, double-blind study. Each subject received four dose regimens, each for 2 weeks, in a random order. The regimens were: 300 mg ranitidine b.d., 20 mg omeprazole o.m., 40 mg omeprazole o.m., and placebo. RESULTS: The decrease in gastric acidity during the daytime and during the total 24-hour period by all three treatments was significantly greater than after placebo; a significant difference in acid inhibition was found between ranitidine and 40 mg omeprazole, but not between ranitidine and 20 mg omeprazole, nor between the two doses of omeprazole. During the night-time the decrease in gastric acidity by all three treatments was significantly greater than after placebo; no difference was seen between the two doses of omeprazole and ranitidine. For the time of pH greater than 3 we found no statistical difference between the various acid decreasing regimens. The pH remained significantly longer above 4 after ranitidine and the two doses of omeprazole compared with placebo, and also longer above 4 after 40 mg omeprazole compared with ranitidine, but not after 20 mg omeprazole compared with ranitidine, nor after the two different doses of omeprazole. CONCLUSIONS: Dosing with 300 mg ranitidine b.d., 20 mg omeprazole or 40 mg omeprazole is superior in gastric acid inhibition compared with placebo, when measured using 24-hour pH monitoring.

Adult↗

PubMed2003

Effect of omeprazole 10 mg on intragastric pH in three different CYP2C19 genotypes, compared with omeprazole 20 mg and lafutidine 20 mg, a new H2-receptor antagonist.

BACKGROUND: Omeprazole 10 mg is used as maintenance therapy for gastro-oesophageal reflux disease, but previous reports have not mentioned the potency of its acid suppression. AIM: To evaluate the potency of acid suppression with omeprazole 10 mg, in relation to CYP2C19 genotypes. METHODS: Eighteen healthy subjects without Helicobacter pylori participated. After a 7-day regimen of omeprazole 10 mg, 20 mg, lafutidine 20 mg (a novel H2-receptor antagonist) or water only (baseline data), intragastric pH was measured for 24 h. RESULTS: With omeprazole 10 mg, greater differences were observed than 20 mg in median pH values and pH > 4 holding time ratios between poor metabolizers (PMs, n = 6) and the others [homozygous extensive metabolizers (homo-EMs, n = 6) and heterozygous extensive metabolizers (hetero-EMs, n = 6)]. With lafutidine 20 mg, these parameters were not influenced by the genotype. The potency of acid suppression was: omeprazole 20 mg approximately lafutidine 20 mg > omeprazole 10 mg in homo-EMs, omeprazole 20 mg > omeprazole 10 mg approximately lafutidine 20 mg in hetero-EMs, and omeprazole 20 mg approximately omeprazole 10 mg > lafutidine 20 mg in PMs. CONCLUSIONS: Omeprazole 10 mg strongly suppresses acid secretion, but depending on the CYP2C19 genotypes shows greater interindividual variations in suppression than 20 mg.

Acetamides↗

PubMed1996

Persistent acid secretion during omeprazole therapy: a study of gastric acid profiles in patients demonstrating failure of omeprazole therapy.

OBJECTIVE: To identify patients with gastroesophageal reflux disease (GERD) who, despite omeprazole 20 mg b.i.d., demonstrate continued abnormal gastric acid secretion. METHODS: Eighty-eight patients with GERD completed ambulatory gastric and esophageal pH monitoring for persistent symptoms on omeprazole 20 mg b.i.d.. Seventeen (19%) demonstrated abnormal gastric acid secretion (percentage time gastric pH < 4 > 50%). The 17 omeprazole failures (OF) were compared with: 1) 19 randomly selected patients with GERD (also studied on omeprazole 20 mg b.i.d. and 2) 19 normal volunteers studied on both placebo and omeprazole 20 mg b.i.d.. Total time intragastric pH < 4, 24-hr gastric pH frequency distribution, and 15-min median pH values for the 6-h period after the evening omeprazole dose were compared. RESULTS: Both the 24-hr frequency distribution for gastric pH and the 15-min median gastric pH profile for patients with GERD and volunteers on omeprazole 20 mg b.i.d. were almost identical. By contrast, gastric pH studies from the OF group receiving omeprazole 20 mg b.i.d. most closely resembled those of the normal subjects receiving placebo, with respect to these variables. Gastric pH monitoring in seven of the 17 OF patients while on omeprazole 80 mg/day demonstrated a significant decrease in the median percentage time gastric pH remained below 4 (32.8% on 80 mg/day vs 74.3% on 40 mg/day; p < 0.02). CONCLUSION: There are individuals whose intragastric acidity persists despite conventional doses of omeprazole. Although the underlying mechanism remains unclear, the majority (six of seven) (87%) demonstrated improved gastric acid control when placed on high dose omeprazole, indicating that this is often a dose-dependent phenomenon.

Anti-Ulcer Agents↗

PubMed2001

Control of intragastric pH with omeprazole 20 mg, omeprazole 40 mg and lansoprazole 30 mg.

BACKGROUND: Single daily doses of proton pump inhibitors, omeprazole and lansoprazole provide effective acid suppression and equal healing and symptom relief in patients with GERD. Despite this, controversy exists as to the efficacy of available proton pump inhibitors in the control of gastric acidity. AIM: To assess the efficacy of omeprazole 20 mg vs. lansoprazole 30 mg and omeprazole 40 mg vs. lansoprazole 30 mg in intragastric pH control. METHODS: Study I: 12 Helicobacter pylori-negative volunteers (mean age 33 years) were treated with omeprazole 20 mg and lansoprazole 30 mg in random order before breakfast for 7 days. Study II: 24 subjects (mean age 36 years) were similarly treated with omeprazole 40 mg and lansoprazole 30 mg for 7 days after a baseline pH study. One week washout was allowed between studies. Subjects had the same meal on each study day. On day seven, a 24-h intragastric pH study was performed. The percentage time for which gastric pH > 4 was analysed (Gastrosoft, Synectics Medical Inc.) and expressed as mean +/- s.d. RESULTS: (1) Omeprazole 20 mg and lansoprazole 30 mg showed no significant difference in the percentage time for which gastric pH > 4 in the daytime and night-time periods. (2) The percentage time for which pH > 4 with omeprazole 40 mg was significantly greater than lansoprazole 30 mg in both daytime (61 +/- 19% vs. 48 +/- 14%, P < 0.001), and night-time periods (34 +/- 21% vs. 26 +/- 14%, P < 0.05). (3) A large inter-subject variation existed in both studies. (4) In 10 subjects who participated in both studies, omeprazole 40 mg showed a significantly higher percentage time for which pH > 4 in the daytime (69 +/- 18% vs. 51 +/- 15%, P=0.015) than omeprazole 20 mg. CONCLUSION: These pH data support the therapeutic equivalency of FDA approved doses of omeprazole and lansoprazole.

2-Pyridinylmethylsulfinylbenzimidazoles↗

PubMed1998

A comparison of omeprazole with ranitidine for ulcers associated with nonsteroidal antiinflammatory drugs. Acid Suppression Trial: Ranitidine versus Omeprazole for NSAID-associated Ulcer Treatment (ASTRONAUT) Study Group.

BACKGROUND: Suppressing acid secretion is thought o reduce the risk of ulcers associated with regular use of nonsteroidal antiinflammatory drugs (NSAIDs), but the best means of accomplishing this is uncertain. METHODS: We studied 541 patients who required continuous treatment with NSAIDs and who had ulcers or more than 10 erosions in either the stomach or duodenum. Patients were randomly assigned to double-blind treatment with omeprazole, 20 mg or 40 mg orally per day, or ranitidine, 150 mg orally twice a day, for four or eight weeks, depending on when treatment was successful (defined as the resolution of ulcer and the presence of fewer than five erosions in the stomach, and fewer than five erosions in the duodenum, and not more than mild dyspepsia). We randomly assigned 432 patients in whom treatment was successful to maintenance treatment with either 20 mg of omeprazole per day or 150 mg of ranitidine twice a day for six months. RESULTS: At eight weeks, treatment was successful in 80 percent (140 of 174) of the patients in the group given 20 mg of omeprazole per day, 79 percent (148 of 187) of those given 40 mg of omeprazole per day, and 63 percent (110 of 174) of those given ranitidine (P<0.001 for the comparison with 20 mg of omeprazole and P=0.001 for the comparison with 40 mg of omeprazole). The rates of healing of all types of lesions were higher with omeprazole than with ranitidine. During maintenance therapy, the estimated proportion of patients in remission at the end of six months was 72 percent in the omeprazole group and 59 percent in the ranitidine group. The rates of adverse events were similar between groups during both phases. Both medications were well tolerated. CONCLUSIONS: In patients with regular use of NSAIDs, omeprazole healed and prevented ulcers more effectively than did ranitidine.

Adult↗

PubMed1989

Omeprazole and cimetidine in the treatment of ulcers of the body of the stomach: a double blind comparative trial. Danish Omeprazole Study Group.

OBJECTIVE: To see whether omeprazole was superior to cimetidine in healing ulcers of the body of the stomach. DESIGN: Double blind randomised parallel group study of omeprazole versus cimetidine for six weeks with assessment of healing at end of every second week. SETTING: Outpatient referrals in 11 centres in Denmark. PATIENTS: One hundred sixty one patients who satisfied the following criteria: age 18-79; one or more ulcers of body of stomach (that is, at or above the angulus) seen endoscopically within four days before study treatment; no H2 receptor antagonists taken within previous two weeks; no history of gastric surgery and no complications needing surgery; no concurrent treatment or disease that might confound assessment; oral contraception or an intrauterine device being used by women of childbearing age. INTERVENTIONS: Omeprazole 30 mg daily (one capsule in the morning) or cimetidine 1 g daily (one 200 mg tablet thrice daily, two tablets at bedtime) for six weeks. Inactive capsules and tablets provided so that all patients took same number of capsules and tablets daily. Compliance monitored by pill counts. END POINT: Endoscopic evidence of accelerated healing of type I gastric ulcers after four weeks of omeprazole. MEASUREMENTS AND MAIN RESULTS: Pain recorded on diary cards and patients assessed after two, four, and six weeks of treatment for clinical state and by endoscopy and biopsy and repeat laboratory tests. Twenty eight patients withdrawn during trial for violations of protocol. At two weeks healing rates were identical in the two treatment groups (omeprazole 41% (30/73 patients); cimetidine 41% (30/73]. At four weeks cumulative healing rates were 77% (53/69 patients) in the omeprazole treatment group and 58% (41/71) in the cimetidine treatment group (95% confidence interval of difference between groups 4% to 34%). By six weeks the cumulative healing rates in the two treatment groups differed by only 6% (60/68 patients (88%) given omeprazole; 53/65 (82%) given cimetidine). Log rank analysis with ulcer size used as covariable showed a significant difference in healing times in favour of omeprazole. There was no difference in the occurrence of pain relief between the two treatment groups. No serious clinical or biochemical side effects of treatment were noted. CONCLUSIONS: Omeprazole 30 mg daily accelerates healing of ulcers in the body of the stomach as compared with cimetidine 1 g daily. This effect is more pronounced in ulcers greater than 12 mm diameter.

Aged↗

PubMed2000

Pharmacokinetics of orally administered omeprazole in children. International Pediatric Omeprazole Pharmacokinetic Group.

OBJECTIVES: The aim of this study was to examine the pharmacokinetics of orally administered omeprazole in children. METHODS: Plasma concentrations of omeprazole were measured at steady state over a 6-h period after administration of the drug. Patients were a subset of those in a multicenter study to determine the dose, safety, efficacy, and tolerability of omeprazole in the treatment of erosive reflux esophagitis in children. Children were 1-16 yr of age, with erosive esophagitis and pathological acid reflux on 24 h-intraesophageal pH study. The "healing dose" of omeprazole was that at which subsequent intraesophageal pH study normalized. Children remained on this dose for 3 months, and during this period the pharmacokinetics were measured. RESULTS: A total of 57 children were enrolled in the overall healing phase of the study. Pharmacokinetic study was optional for subjects and was performed in 25 of the 57 enrolled. The doses of omeprazole required were substantially higher doses per kilogram of body weight than in adults. Values of the pharmacokinetic parameters of omeprazole were generally within the ranges previously reported in adults. However, the plasma levels, area under the plasma concentration versus time curve (AUC), plasma half-life (t(1/2)), and maximal plasma concentration (Cmax), were lower in the younger age group, when the AUC and Cmax were normalized to a dose of 1 mg/kg. Furthermore, within the group as a whole, these values showed a gradation from lowest in the children 1-6 yr of age to higher in the older age groups. CONCLUSIONS: The pharmacokinetics of omeprazole in children showed a trend toward higher metabolic capacity with decreasing age, being highest at 1-6 yr of age. This may explain the need for higher doses of omeprazole on a per kilogram basis, not only in children overall compared with adults but, in many cases, particularly in younger children.

Administration, Oral↗

PubMed1990

Effect of omeprazole treatment on diazepam plasma levels in slow versus normal rapid metabolizers of omeprazole.

The effect of omeprazole treatment on diazepam plasma levels was studied in four slow and six rapid metabolizers of omeprazole. Single intravenous doses of diazepam (0.1 mg/kg) were administered after 1 week of oral treatment with omeprazole (20 mg) and placebo. This was a double-blind crossover study with randomized placebo and omeprazole treatments. Blood was collected up to 120 hours after diazepam dosing (still during one-daily omeprazole and placebo administration) for measurement of diazepam and its major metabolite desmethyldiazepam. The slow metabolizers of omeprazole also metabolized diazepam slowly, exhibiting only half the diazepam plasma clearance of the others. The mean clearance of diazepam was decreased 26% after omeprazole in the rapid metabolizers, whereas the slow group showed no apparent interaction. The mean plasma concentrations of desmethyldiazepam showed a more rapid formation in the rapid compared with the slow metabolizers, which is a logical consequence of the rate of diazepam metabolism.

Adult↗

PubMed1998

One-week triple therapy using omeprazole, amoxycillin and clarithromycin for the eradication of Helicobacter pylori in patients with non-ulcer dyspepsia: influence of dosage of omeprazole and clarithromycin.

BACKGROUND: Triple therapy based upon omeprazole, amoxycillin and clarithromycin for 7 days is the reference treatment used in France for the eradication of Helicobacter pylori. However, optimal dosages of omeprazole and clarithromycin have not been determined. AIMS: To compare four eradication regimens using this treatment in patients with non-ulcer dyspepsia. METHODS: Two hundred and seventy-four patients with symptoms of dyspepsia, normal upper GI endoscopy and a positive urease test were included in the study. A 13C-urea breath test (UBT) was obtained before and 6 weeks after treatment. Patients were randomized to one of the following 7-day regimens: 20 mg omeprazole o.m. plus amoxycillin 1000 mg b.d. plus clarithromycin 250 mg b.d. (O20AC500) or 20 mg omeprazole o.m. plus amoxycillin 1000 mg b.d. plus clarithromycin 500 mg b.d. (O20AC1000) or 20 mg omeprazole b.d. plus amoxycillin 1000 mg b.d. plus clarithromycin 250 mg b.d. (O40AC500) or 20 mg omeprazole b.d. plus amoxycillin 1000 mg b.d. plus clarithromycin 500 mg b.d. (O40AC1000). Compliance was assessed by returned tablet counts. Eradication was defined as conversion from positive 13C-UBT at entry to negative 13C-UBT 6 weeks after cessation of therapy. RESULTS: Two hundred and fifty-eight patients were included in the intention-to-treat (ITT) analysis. From the least to the most effective regimen, eradication rates were: O20AC1000: 60.0% (95% CI: 47.6-72.4), O20AC500: 64.1% (52.3-75.8), O40AC1000: 64.2% (52.7-75.7), O40AC500: 74.6% (64.2-85.0) (N.S.). Overall compliance was good in 92% of patients. The most frequent adverse events were diarrhoea and taste impairment, occurring mainly in the high-dose clarithromycin groups. CONCLUSIONS: Eradication rates obtained in this study were lower than those expected on the basis of previously reported studies. This study supports the use of a double dose of omeprazole, although the difference between groups was non-significant, but provides no argument in favour of a high dose of clarithromycin.

Amoxicillin↗

PubMed1992

Omeprazole (20 mg) daily given in the morning or evening: a comparison of effects on gastric acidity, and plasma gastrin and omeprazole concentration.

Although omeprazole has a long duration of action and has usually been given in the morning, there are theoretical advantages in administering antisecretory drugs in the evening as has been shown for the H2-receptor antagonists. The aim of this study was to compare the effects of placebo and 20 mg omeprazole given either in the morning or evening, on gastric acidity, plasma gastrin levels and plasma omeprazole in 6 duodenal ulcer patients. The 24-hour mean pH (+/- S.E.M.) was: placebo 1.7 +/- 0.1; morning doing, 3.9 +/- 1.8 (P less than 0.01); evening dosing, 2.9 +/- 1.1 (N.S.). There was a large inter-individual variability of intragastric acidity in response to omeprazole, which was reflected both in the plasma gastrin and in the area under the plasma omeprazole concentration-time curve. Morning administration of omeprazole is optimal, but variability in the patient response to 20 mg omeprazole is still seen.

Double-Blind Method↗

PubMed2001

Bioequivalence between omeprazole MUPS 20 mg as tablet and omeprazole MUPS 20 mg as tablet encapsulated in a hard gelatine capsule.

AIMS: To investigate pharmacokinetic characteristics of omeprazole MUPS 20 mg tablets and its encapsulated form. MATERIAL AND METHODS: Bioequivalence of omeprazole MUPS 20 mg tablet (Reference) and omeprazole MUPS 20 mg tablet in a hard gelatine capsule (Test) was evaluated in a randomized, 2-period crossover study in 38 healthy male Caucasian subjects who received a single oral dose of 20 mg omeprazole in each study period. Serum concentrations of omeprazole MUPS 20 mg were measured using an HPLC assay. In addition, in vitro dissolution profiles were studied. RESULTS: Both formulations were bioequivalent as assessed by the primary pharmacokinetic characteristics AUC(0-infinity) and Cmax, the corresponding ratios (Test/Reference) being 0.97 and 0.98, respectively. Thus, the 90% CI of these ratios were within the equivalence range of 0.8 to 1.25 for AUC(0-infinity) (CI 0.90-1.04) and 0.67 to 1.50 for Cmax (Cl 0.86-1.10). The ratios of the secondary criteria, Cmax/AUC(0-infinity) and t 1/2, were also within the equivalence range. Median tmax of Reference and Test was identical. Both formulations revealed comparable dissolution profiles with high batch conformity and homogeneity releasing > 80% omeprazole within 1 hour. Both study formulations were well tolerated without relevant differences. CONCLUSION: The encapsulation of omeprazole MUPS 20 mg tablets does not influence the extent and rate of absorption as indicated by the AUC and Cmax ratios. Thus, bioequivalence could be demonstrated.

Adult↗

PubMed1991

Omeprazole 20 mg uid and ranitidine 150 mg bid in the treatment of benign gastric ulcer. Italian Cooperative Group on Omeprazole.

The primary aim of this double-blind, randomized Italian multicenter trial was to compare the healing rates in patients with benign gastric ulcers after 4-8 weeks treatment with either omeprazole 20 mg uid or ranitidine 150 mg bid. Secondary aims were to compare the healing rates in a subgroup of patients after two weeks and to study symptom relief and frequency of adverse events. One hundred and sixty-seven (167) patients were randomized to treatment with either omeprazole (84) or ranitidine (83). Four and three patients in the omeprazole and ranitidine groups, respectively, were found to have malignant gastric ulcers, and were therefore excluded from the analysis. Protocol healing rates were significantly higher in the omeprazole group (35%, 74% and 96%) than in the ranitidine group (9%, 53% and 85%) after two (p = 0.004), four (p = 0.015) and eight weeks (p = 0.04) of treatment (chi 2 test). Relief of both daytime and nocturnal epigastric pain, as reported on clinic visits, was more rapid in the omeprazole group than in the ranitidine group. Diary card reports of nocturnal and day pain during the first two weeks showed a similar pattern, with somewhat faster relief of pain in the omeprazole group. Both omeprazole and ranitidine were well tolerated, and only few adverse events were reported. No changes in the laboratory tests were considered to be clinically important.

Double-Blind Method↗

PubMed1991

U.S. experience with omeprazole in duodenal ulcer. Multicenter double-blind comparative study with ranitidine. The Omeprazole DU Comparative Study Group.

To assess the comparative efficacy of omeprazole 20 mg, a proton pump inhibitor, versus ranitidine 150 mg twice a day, an H2-receptor antagonist, in healing duodenal ulcers we performed a randomized, double-blind, multicenter trial in 309 patients with endoscopically diagnosed ulcers. Patients were treated for up to four weeks and were seen at week 2 and at week 4, if unhealed at week 2, for determination of ulcer status by endoscopy, review of daily self-assessment symptom diaries, and clinical laboratory including fasting serum gastrin. Gastrin levels were repeated two weeks after cessation of study medication. Evaluation of baseline demographic and laboratory parameters demonstrated no significant differences between the two groups at entry. At week 2, 42% of the omeprazole and 34% of the ranitidine-treated patients were healed (P = NS). At week 4, there was a 19% advantage in ulcer healing for the omeprazole-treated patients in comparison to those treated with ranitidine (82% vs 63%, respectively, P less than 0.05). Healing of ulcers greater than or equal to 1.0 cm occurred in 83% of those treated with omeprazole versus 37% treated with ranitidine (P less than 0.01). There were no significant differences in rate of pain relief or incidence of clinical laboratory abnormalities. Mean fasting serum gastrin value during treatment increased over the baseline in both groups, (P less than 0.05). The percent change was significantly greater with omeprazole but few patients had elevations above the upper limit of normal for the assay. Both drugs were well tolerated. Omeprazole 20 mg demonstrated superiority in healing duodenal ulcers at four weeks in comparison to ranitidine 150 mg twice daily and was more effective in healing ulcers greater than or equal to 1.0 cm.

Double-Blind Method↗

PubMed2005

Rabeprazole is equivalent to omeprazole in the treatment of erosive gastro-oesophageal reflux disease. A randomised, double-blind, comparative study of rabeprazole and omeprazole 20 mg in acute treatment of reflux oesophagitis, followed by a maintenance open-label, low-dose therapy with rabeprazole.

BACKGROUND: Previous studies have shown similar effects of rabeprazole and omeprazole, when used at the same dose in the treatment of reflux oesophagitis. However, such studies have been conducted as superiority studies but interpreted as equivalence ones. AIM: To properly assess the comparative efficacy of rabeprazole and omeprazole in inducing complete endoscopic healing and symptom relief in patients with reflux oesophagitis. METHODS: Patients (n=560) with Savary-Miller grade I-III reflux oesophagitis were randomised in a double-blind, double-dummy fashion to rabeprazole or omeprazole 20 mg once daily for 4-8 weeks. Then, patients endoscopically healed and symptomatically relieved were openly maintained with rabeprazole 10 mg or 2x10 mg once daily (in the event of clinical and/or endoscopic relapse) for a maximum of 48 weeks. RESULTS: After 4-8 weeks of treatment, healing (primary end-point) was observed in 228/233 (97.9%) patients in the rabeprazole group and in 231/237 (97.5%) in the omeprazole one (equivalence effect demonstrated by p<0.0001 at Blackwelder test and an upper confidence limit at 97.5% of 0.023). However, rabeprazole was faster in inducing heartburn relief than omeprazole (2.8+/-0.2 versus 4.7+/-0.5 days of therapy to reach the first day with satisfactory heartburn relief, p=0.0045 at log-rank test). In the maintenance phase, 15.2% of patients had an endoscopic and/or clinical relapse. CONCLUSION: Rabeprazole is equivalent to omeprazole in healing reflux oesophagitis, but shows a faster activity on reflux symptoms in the early treatment phase.

2-Pyridinylmethylsulfinylbenzimidazoles↗