Comparative tolerability profile of omeprazole in clinical trials

The effect of artificial light at night on the biomass of caterpillars feeding in urban tree canopies

Alternation of day and night is the oldest cycle on Earth, which is increasingly disturbed by the accelerating rate of urbanization and technological development. Despite the ubiquity of light pollution in cities, many aspects of its influence on urban ecosystems are still poorly understood. Here we studied the effect of artificial light at night (ALAN) on the biomass of arboreal caterpillar populations, which are a major component of the diet of many insectivorous animals. We predicted that increasing ALAN intensity is associated with reduced caterpillar biomass, because ALAN may increase predation risk for both caterpillars and adult lepidopterans (i.e. moths), and can also hinder the moths’ reproductive rate. We estimated caterpillar biomass from frass samples (n = 3061) collected from 36 focal trees in two cities in Hungary during four consecutive years. To quantify ALAN we measured light intensity during night at each focal tree (range of illumination: 0.69–3.18 lx). We found that caterpillar biomass of individual trees was repeatable over the four years. This temporal consistency in prey biomass production may be important for birds because it can help predict territory quality, especially in cities where caterpillar abundance is generally low. Our results did not support the negative effect of ALAN on urban caterpillar populations, because ALAN intensity was not related to caterpillar biomass, and this lack of effect was consistent between study sites and tree species. We suggest that the effect of ALAN on urban caterpillar biomass is either weak and thus can be masked by other, local environmental factors, or light pollution may have antagonistic effects acting during different stages of the lepidopteran life cycle. Another explanation could be that even the lower levels of our sites’ public lighting are strong enough to cause serious detrimental effects for caterpillars, resulting in their uniformly low biomass.

Current Status of Gastric Proton Pump Inhibitors in the Treatment of Acid-Peptic Disease

Proton pump inhibitors represent an important advance in the treatment of acid-peptic disease. Omeprazole, the prototype of the drug class, produces a profound and sustained degree of gastric acid suppression. Recent studies confirm earlier reports that omeprazole 20 mg/d is generally more effective than standard histamine2 receptor antagonist (H2RA) dosage regimens in treating duodenal ulcer (DU), gastric ulcer (GU), and erosive esophagitis. Omeprazole tends to accelerate DU and GU healing, especially during the first 2 weeks of treatment, and also accelerates mucosal healing in patients with all grades of esophagitis. Omeprazole is the drug of choice for treating patients with large or refractory ulcers, severe or refractory erosive esophagitis, Barrett's esophagus, and Zollinger-Ellison syndrome. Maintenance therapy with omeprazole seems to reduce ulcer recurrence and esophagitis, but optimal treatment regimens must be established. Dual therapy with omeprazole and amoxicillin shows encouraging results in eradicating Helicobacter pylori, reducing duodenal ulcer recurrence rates, and altering the natural history of peptic ulcer disease. Further studies are required to determine the efficacy of omeprazole in preventing nonsteroidal anti-inflammatory drug-induced ulcers and stress-related mucosal bleeding, and in treating upper gastrointestinal bleeding. Omeprazole is well-tolerated in the majority of patients receiving either short-term or long-term treatment. The type and frequency of adverse effects are similar to those reported with the H2RAs. There is no evidence to support genotoxicity or hypergastrinemia-induced enterochromaffin-like cell carcinoid of the stomach in patients receiving omeprazole treatment for more than 5 years. Omeprazole interacts selectively with hepatic P-450 and may potentially interact with phenytoin, warfarin, or diazepam. Pharmacoeconomic studies suggest that treatment with omeprazole provides a significant cost-savings over the H2RAs in patients with moderate to severe erosive esophagitis and possibly in patients with DU. Lansoprazole, a newly developed proton pump inhibitor, seems to offer no clear advantage over omeprazole.

Safety of lansoprazole

The care with which patients are monitored during clinical trials provides an excellent database to assess the tolerability and safety of drugs. Additional information can be obtained from knowledge of the compound itself, its metabolism and its pharmacological action. Other compounds from the same class can highlight areas that need particular study. All these factors have been used to assess the safety of lansoprazole. Lansoprazole has been administered to 4749 subjects and has been well tolerated. Only 1.2% of patients have been withdrawn from trials because of suspected drug-related events but there was no pattern and no relationship to drug dosage. Diarrhoea (3.2%) and headache (4.7%) were the most commonly reported adverse events.

Omeprazole-induced hepatitis

Omeprazole; the first proton pump inhibitor (PPI) showing an effective acid inhibitory ability, provides the satisfactory therapy either in gastro-esophageal reflux symptom relief or in healing of erosive esophagitis. It's also effective in peptic ulcer disease. Up to date, omeprazole efficacy and safety are well established in many trials. Omeprazole-related hepatotoxicity is not very well recognized especially in pediatric population. We report a child who developed hepatitis following omeprazole intake. We believe that this is the first case report of omeprazole-induced hepatitis in pediatric population.

Comparison of Prilosec OTCTM (omeprazole magnesium 20.6 mg) to placebo for 14 days in the treatment of frequent heartburn

PURPOSE

Consumer surveys have identified an over-the-counter (OTC) medication that provides complete and long-lasting relief of frequent heartburn as an unmet consumer need. The purpose of the two identical studies reported in this paper was to evaluate the safety and effectiveness of 10.3 and 20.6 mg omeprazole magnesium, referred to as Ome-Mg 10 and Ome-Mg 20, respectively (equivalent to 10 and 20 mg omeprazole) for the treatment of frequent heartburn administered as a novel 14-day OTC regimen.

SUBJECTS AND METHODS

Subjects with frequent heartburn (heartburn two or more days per week) took Ome-Mg 10, Ome-Mg 20, or placebo for 14 consecutive mornings. Statistical analyses compared percentage of subjects with no heartburn 24 h after the first dose, after the last dose (day 14), and percentage of days that subjects were heartburn-free. Nocturnal heartburn and heartburn rated no more than mild were also assessed.

RESULTS

Twenty-four hours following the first dose, nearly 50% of subjects receiving Ome-Mg 20 reported no heartburn, and more than 80% receiving Ome-Mg 20 had no more than mild heartburn. Both doses were significantly more effective than placebo on days 1 and 14 for percentage of subjects heartburn-free for 24 h (P < or = 0.003), and across all 14 days for percentage of heartburn-free days (P < 0.001). Ome-Mg 20 was significantly more effective than placebo in preventing nocturnal heartburn across all 14 days (P < 0.001). Ome-Mg was well tolerated.

CONCLUSION

These trials demonstrated the safety and effectiveness of a novel 14-day regimen of Ome-Mg 20 in completely preventing heartburn for 24 h establishing it as an excellent self-care treatment for frequent heartburn and supporting the approval of Prilosec OTC.

Single-Isomer Drugs

Chirality is one of the main features of biology, and many of the processes essential for life are stereospecific, meaning that one out of two or more isomers may work best in a particular physiological situation. Could this be used in drug development and result in any clinical relevance and true therapeutic advance? There are occasions when the development of one of the isomers might be expected to be advantageous: for example, only one of the isomers may be active, only one of the isomers may cause adverse effects, or one of the isomers may have more advantageous pharmacological properties. As an example of the last, the successful development of esomeprazole will be described. Before the introduction of esomeprazole, the proton pump inhibitor omeprazole was the standard treatment for gastric acid-related diseases, such as gastro-oesophageal reflux disease. A serious type of gastro-oesophageal reflux disease is erosive oesophagitis, an increasingly common condition that may lead to life-threatening complications. Doubling the standard dose of omeprazole from 20 to 40 mg did not improve healing rates (74% versus 75%), and thus a substantial proportion of patients remained unhealed with standard treatment. The (S)-isomer of omeprazole, esomeprazole, was shown to heal more patients than omeprazole as a result of unique metabolic properties that clearly differentiates esomeprazole from omeprazole, the racemate. At comparable doses, these properties lead to several clinical advantages: higher bioavailability in extensive metabolisers (the majority of patients), lower exposure in poor metabolisers, less interindividual variation and a steeper dose-response curve at steady state resulting in a more pronounced inhibition of gastric acid secretion. Esomeprazole has been studied clinically for a variety of acid-related conditions, showing that the compound is as well tolerated and more effective with regard to healing and symptom relief than the recommended treatment with omeprazole. Thus, from this example it is clear that the exploration and development of single-isomer drugs may bring significant advances in treatment options.

Hepatic lysosomal enzymes activity and liver morphology after short-time omeprazole administration

The aim of the study was to establish the influence of short-time omeprazole administration on liver function and morphology. Omeprazole was administered intraperitoneally, twice daily, for 3 days to male Wistar rats in two doses: 0.571 mg/kg and 5.71 mg/kg. Control animals were treated with physiological saline. Half of the animals were sacrificed 12 hours after the last injection. The remaining rats were raised for another 6 weeks, without any xenobiotics, and sacrificed on the 47th day of the experiment. The activity of free and bound fractions of hepatic acid phosphatase, beta-galactosidase, beta-N-acetyl-glucosaminidase, cathepsin B, D and L, lipase, and sulphatase were determined spectrophotometrically in homogenates of the liver. The liver sections were examined by light microscopy with hematoxylin-eosin, azan, and periodic acid-Schiff stains. Marginally significant (p < 0.1) differences in activity of free sulphatase fraction, and free and bound fractions of beta-galactosidase were found in animals exposed to the higher dose of omeprazole and sacrificed 12 hours after the last injection. Enzymatic profiles were normalised during the next 6 weeks. Histological evaluation revealed small degenerative and adaptive changes in all examined groups. It could be concluded that observed differences of hepatic lysosomal enzyme activities were the result of accompanied chemical-induced peritonitis as previously reported, and not a direct drug-toxic effect.

Collagenous colitis associated with lansoprazole

BACKGROUND

Collagenous colitis is a diarrheal illness of unknown cause. The purpose of this report is to describe a case of collagenous colitis related to lansoprazole exposure.

STUDY

Case report.

RESULTS

A patient is described who developed clinical and pathologic findings of collagenous colitis during treatment with lansoprazole and omeprazole. Symptoms of diarrhea and histopathologic abnormalities resolved after drug withdrawal and recurred with re-exposure to lansoprazole.

CONCLUSIONS

The observations are compatible with collagenous colitis or lymphocytic colitis associated with exposure to lansoprazole.

Omeprazole-induced leukopenia. A case report

BACKGROUND

Omeprazole has been marketed in France since 1989, for the healing of peptic ulcers, erosive reflux oesophagitis, and the Zollinger-Ellison syndrome. However, the drug has been associated with serious adverse reactions, including haemolytic anaemia and acute interstitial nephritis. More recently, an autoimmune syndrome induced by omeprazole has been described.

OBJECTIVE

We present here a clinical history and an in vitro test of cytotoxicity linking leukopenia to omeprazole.

RESULTS

A 37-year-old woman was hospitalized in the intensive care unit of our hospital with acute pulmonary insufficiency secondary to pneumonia. 72 h after starting omeprazole treatment, a decrease in leucocyte count was observed. The leukopenia was maximal on day 22: total white cell count was 2. 1x109/l, and neutrophil count was less than 0.75x109/l. In order to find the cause of this leukopenia, an in vitro cytotoxicity test was performed. The test was positive only when patient neutrophils and patient serum were in the presence of omeprazole. This cytotoxicity seems to be complement-dependent, as in the presence of heated serum, the omeprazole toxic effect was substantially reduced.

CONCLUSION

This case report suggests that the leukopenia was associated with omeprazole.

Acceptability of a paste formulation and efficacy of high dose omeprazole in healing gastric ulcers in horses maintained in race training

Gastric ulceration has been found to occur in 80-90% of Thoroughbreds in active race training. Previously, variable success has been reported using mucosal surface protectants and H2 receptor antagonist. Omeprazole, a substituted benzimidazole, has been shown to inhibit gastric acid secretion in both man and animals. Fourteen horses, in active race training and with endoscopic evidence of moderated to severe gastric ulceration were divided into 2 groups: Group 1 (7 horses) were given placebo paste orally once daily for 28 days; Group 2 (7 horses) received 1.54 g active omeprazole in the placebo once daily for 28 days. Logs detailing administration and acceptability of the paste, and the horse's feeding and training regime were maintained by the trainer of each horse. Endoscopic examination of the stomach occurred at the beginning of the trial, and at 13-17 days and 27-31 days following commencement of the trial. Those horses that were free of ulceration on Days 27-31 were reexamined on Days 35-49. Acceptability of the paste, whether with or without active omeprazole, was deemed excellent in all horses except on one occasion, when one horse swallowed the paste following initial mild reluctance. Of the horses given the placebo (Group 1), 3 were withdrawn after the 13-17 day endoscopic examination: 1 horse to be given a H2 receptor antagonist, 1 horse was removed from training due to aryepiglottic entrapment and 1 horse had a greater than 10% fall in bodyweight from the start of the trial. Of the horses given active omeprazole (Group 2), one horses was relocated to another race track following the 13-17 day endoscopic examination. For the horses given placebo (Group 1), there was no change in the severity of ulceration. In contrast, the severity of ulceration in the horses given active omeprazole was significantly reduced at 13-17 days and 27-31 days. In 2 Group 2 horses, ulcers that had been completely eliminated subsequently returned when reexamined at 35-49 days. The results of this study suggest that omeprazole, employing a once daily dosing schedule, is effective at reducing the severity or eliminating gastric ulcers in Thoroughbreds in active race training.

Comparative role of omeprazole in the treatment of gastroesophageal reflux disease

OBJECTIVE

To review gastroesophageal reflux disease (GERD) and its treatment, with emphasis on the use and place of omeprazole, a proton pump inhibitor.

DATA SOURCES

A compilation prepared by the National Library of Medicine's Interactive Retrieval Services (Medlars II) for the period 1987 to 1994 was used as the data source.

STUDY SELECTION

Focus was placed on human comparative clinical studies with well-accepted measures of esophageal healing (endoscopy) and symptom resolution. Safety data were compiled from the clinical trials literature and large postmarketing data studies. Pharmacoeconomic studies selected were judged to meet the criteria of good design, presence of sensitivity testing, and statement of perspective.

DATA EXTRACTION

Data were obtained from double-blind, controlled clinical studies. Other data were extracted from pertinent literature of good design and significant results.

DATA SYNTHESIS

Overall, the clinical trials of omeprazole for the treatment of patients with erosive GERD demonstrate that omeprazole provides superior therapy in terms of esophageal healing symptom resolution and patient compliance when compared with histamine2-receptor antagonists (H2RAs) and antacids. In addition, studies also indicate that omeprazole is the most effective agent for the treatment of patients with GERD refractory to other treatments. Dosage adjustment is not necessary in patients with impaired renal or hepatic function or in the elderly. Finally, although the acquisition drug cost for daily treatment of patients with GERD is highest with the use of omeprazole, pharmacoeconomic studies indicate that treatment is more cost-effective with the use of omeprazole than with H2RA or antacid treatment alone or combined with nonpharmacologic approaches.

CONCLUSIONS

Based on efficacy, safety, and cost-effectiveness, omeprazole is the drug of choice for the treatment of patients with endoscopically confirmed erosive GERD.

Gastroesophageal reflux laryngitis resistant to omeprazole therapy

Gastroesophageal reflux disease (GERD) is known to cause a variety of symptoms that lead a patient to seek otolaryngologic care. New advances in the treatment of GERD have enabled otolaryngologists to eliminate most of the signs and symptoms caused by acid reflux. Omeprazole, the most recent pharmacologic advancement, has been reported to be universally successful in controlling acid release from the stomach of patients with GERD. This report describes a series of patients with GERD for whom high-dose omeprazole therapy was not successful in completely reducing gastric acid levels of GERD symptomatology.

Omeprazole. An update of its pharmacology and therapeutic use in acid-related disorders

Omeprazole, a gastric acid pump inhibitor, dose-dependently controls gastric acid secretion: the drug has greater antisecretory activity than histamine H2-receptor antagonists. Omeprazole 20 to 40 mg/day is more effective than histamine H2-receptor antagonists in the short term treatment of duodenal ulcer, gastric ulcer and reflux oesophagitis. Available data suggest that omeprazole 10 to 40 mg/day is also more effective than ranitidine in the maintenance therapy of duodenal ulcer and reflux oesophagitis. The drug is also effective in patients with duodenal ulcer, gastric ulcer or reflux oesophagitis poorly responsive to histamine H2-receptor antagonists. The efficacy of omeprazole 20 mg/day appears to be similar to that of lansoprazole 30 mg/day in the short term treatment of duodenal ulcer, gastric ulcer and reflux oesophagitis. However, most available studies have been reported in abstract form only, and 2 of 3 studies in patients with duodenal ulcer have shown greater healing rates at 2 (but not 4) weeks with lansoprazole. Helicobacter pylori eradication decreases duodenal ulcer relapse rates and appears to be associated with improved duodenal ulcer healing rates. Evidence also suggests that H. pylori eradication is associated with reduced gastric ulcer relapse rates. Omeprazole monotherapy may suppress but does not eradicate H. pylori infection. Eradication rates with omeprazole 20 or 40 mg twice daily plus amoxicillin usually up to 2 g/day (3 g/day in a few studies) for 2 weeks appear to be similar to those of standard triple therapy (bismuth salt plus metronidazole, plus tetracycline or amoxicillin) or omeprazole plus clarithromycin, although eradication rates vary widely. Omeprazole plus amoxicillin appears to be better tolerated than triple therapy and represents a first-line treatment alternative in patients with H. pylori-associated peptic ulcer disease. Omeprazole plus amoxicillin plus metronidazole appears to be more effective than omeprazole plus amoxicillin in patients with metronidazole-sensitive H. pylori infection. Omeprazole remains a treatment of choice in patients with Zollinger-Ellison syndrome. The dosages should be adjusted according to individual response. However, relatively low dosages of 10 to 40 mg/day may be sufficient in some patients. The drug has also shown promise in the treatment of children with severe reflux oesophagitis, in patients with reflux oesophagitis and coexisting systemic sclerosis, and in the prevention of aspiration pneumonia. Evidence suggests that omeprazole is more effective than ranitidine in patients with nonsteroidal anti-inflammatory drug (NSAID)-induced gastric damage who continue to take NSAIDs, especially in patients with large gastric ulcers; however, completion of ongoing studies is required to verify this.(ABSTRACT TRUNCATED AT 400 WORDS)

Omeprazole overdose

The clinical features and pharmacokinetics of omeprazole in overdose have not previously been described. We report 2 cases. The major clinical features were flushing, tachycardia and headache. Omeprazole pharmacokinetics remained unchanged in overdose.