omeprazole, Prilosec
Omeprazole, Helicobacter pylori status, and alterations in the intragastric milieu facilitating bacterial N-nitrosation.

Mowat C, Williams C, Gillen D, Hossack M, Gilmour D, Carswell A, Wirz A, Preston T, McColl KE.

University Department of Medicine and Therapeutics, Western Infirmary, Glasgow, Scotland.

BACKGROUND & AIMS: Omeprazole produces greater acid inhibition in Helicobacter pylori-positive than -negative subjects. We investigated whether this is accompanied by more profound changes in the intragastric milieu that facilitates bacterial synthesis of N-nitroso compounds. METHODS: Gastric juice pH; nitrite, ascorbic acid, and total vitamin C concentrations; and colonization by other bacteria were examined before and during omeprazole treatment in subjects with and without H. pylori infection. Studies were performed in the fasting state and after consumption of 2 mmol nitrate (equivalent to a salad meal). RESULTS: Before omeprazole, H. pylori-positive and -negative subjects were similar for all parameters. During omeprazole, H. pylori-positive subjects had a higher intragastric pH (7.8 vs. 3.0; P < 0.00001) and greater colonization with non-H. pylori species (5 x 10(7) vs. 5 x 10(5) CFU/mL; P < 0.05). These bacteria included nitrosating species. During omeprazole treatment, H. pylori-positive subjects had higher intragastric nitrite levels after the nitrate meal (median area under the concentration/time curve, 12,450 vs. 4708 micromol/L. min; P = 0.04). Omeprazole lowered intragastric vitamin C levels in H. pylori-positive but not -negative subjects (1.8 vs. 3.4 microg/mL, respectively; P = 0.02). CONCLUSIONS: In H. pylori-positive subjects, omeprazole produces disturbances in intragastric nitrite, vitamin C, and bacterial colonization that facilitate bacterial N-nitrosation. This may place them at increased risk of mutagenesis and carcinogenesis.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10930369&dopt=Abstract omeprozole Prilosec



omeprazole, Prilosec
[The role of omeprazole in the eradication of Helicobacter pylori in patients with duodenal ulcers]

[Article in Croatian]

Gribajcevic M, Vanis N, Salaka U, Pasalic G.

Klinika za gastroenterohepatologiju, Klinicki centar Univerzteta u Sarajevu.

BACKGROUND: This research study has tried to establish efficiency of omeprazole, in combination with two antibiotics (metronidazol and amoxicilin), with the aim to eradicate Helicobacter pylori (H. pylori). Efficiency of omeprazole in healing duodenal ulcer has also been observed. PATIENTS AND METHODS: Patients suffering from dyspeptic problems and duodenal ulcer but positive H. pylori status (proved with CLO test) have been examined. Patients have been treated during the first seven days with triple therapy (omeprazol 2 x 20 mg, metronidazol 2 x 500 mg and amoksicilin 2 x 1000 mg). Subsequently, the patients were ordered omeprazole 20 mg in the one single morning dose in period of 21 days. Control endoscopy with the view of establishing the rate of healing ulcer and eradicating H. pylori was made four weeks after the beginning of the therapy. RESULTS: Complete eradication of H. pylori was found with 35/43 (81.4%) patients, and alleviation of ulcer was achieved with 40/43 (93.1%) patients. Not a single patient had any complication after the beginning of treatment with omeprazole. Five patients (11.6%) had increased dyspeptic problems but interruption of the therapy was not required. CONCLUSION: Triple therapy with omeprazole, metronidazol and amoxicilin brings a high rate of eradication H. pylori and healing duodenal ulcer. Therapy is being well tolerated, the pain and dyspeptic problems are being quickly removed.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10934834&dopt=Abstract omeprozole Prilosec



omeprazole, Prilosec
Omeprazole inhibits phagocytosis and acidification of phagolysosomes of normal human neutrophils in vitro.

Agastya G, West BC, Callahan JM.

The Department of Medicine Research Laboratory, Huron Hospital, East Cleveland, OH 44112, USA.

We postulated omeprazole inhibition of the neutrophil proton pump, impairing phagocytosis and phagolysosomal acidification. Neutrophils from healthy human beings were treated with omeprazole prodrug 0.5 mM/l or acid activated omeprazole 0.5 mM/l, then incubated with killed Saccharomyces cerevisiae stained with bromcresol purple. Wet mounts were done at 10, 30 and 60 minutes. Percent neutrophils phagocytosing, percent yeast phagocytosed, and yeast per phagocytosing neutrophil were significantly decreased in acid activated omeprazole compared to controls and omeprazole prodrug. In contrast, percent acidification of intracellular yeast was significantly lower in both omeprazole prodrug and acid activated omeprazole compared to controls. Over time, control neutrophils showed an increase in percent yeast phagocytosed and yeast per phagocytosing neutrophil. When treated with acid activated omeprazole, the percent of neutrophils phagocytosing progressively decreased over time. We observed 1) omeprazole prodrug does not inhibit neutrophil phagocytosis but does inhibit phagolysosomal acidification, whereas 2) acid activated omeprazole inhibits both neutrophil phagocytosis and phagolysosome acidification. We conclude that omeprazole impairs these neutrophil functions in vitro.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10952036&dopt=Abstract omeprozole Prilosec



omeprazole, Prilosec
Stability of capsules containing omeprazole in enteric coated pellets.

Palummo M, Cingolani A, Dall L, Volonte MG.

Catedra de Ensayo y Valoracion de Medicamentos, Facultad de Ciencias Exactas, UNLP, La Plata, Argentina.

The aim of the present study was to comparatively evaluate the stability of capsules containing 20 mg of Omeprazole, in enteric coated pellets, from seven pharmaceutical laboratories on Argentine market. The stability test was performed under the conditions indicated by the ICH: 40 degrees C, 75% HR, with and without light, during a six month period. The remaining content of Omeprazole, total percentage of impurities and percentage of released active principle in vitro, were determined by HPLC. The organoleptic characteristics of the pellets were visually examined. The results obtained at six months indicate that, from the seven products studied, four were found to have a content of Omeprazole higher than 90% of the labeled amount, in both lighting conditions tested, and also comply with the USP23 specifications with respect to the release in vitro. We conclude that the progressive darkening of the pellets indicates, qualitatively, the level of degradation of the product and that the stability of Omeprazole depends on the correct formulation and the primary container.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10961022&dopt=Abstract omeprozole Prilosec