OMEPRAZOLE AND DRY MOUTH

Background: Omeprazole causes irreversible inhibition of the hydrogen/ potassium adenosine triphosphatase enzyme, leading to a marked reducti on in both acid secretion and volume of gastric juice. Reported side-e ffects include nausea, vomiting, diarrhoea, constipation, and headache . We report the development of dry mouth during omeprazole therapy. Me thods: We have identified six patients taking omeprazole for more than 6 weeks who complained of a dry mouth. Salivary production was measur ed as whole salivary Bow produced over a 10-min period spat into a col lecting vessel and as 5% citric acid-stimulated parotid salivary flow collected with a Lashley cup device placed over the parotid duct. Flow rates were evaluated both during and after cessation of treatment. Sa liva produced was then cultured for microbes. Results: Four of the six had subnormal parotid or whole salivary flow rates on treatment that recovered after stopping treatment. The increase after treatment was m arked in four. Significant amounts of Candida albicans grew from the s aliva of the three patients with the lowest salivary flows; one saliva also grew Staphylococcus aureus. Conclusion: Salivary flow is reduced in some patients treated with omeprazole, returning to normal after c essation of treatment. This reduction may predispose to opportunistic infection, particularly in the edentulous.