THE EFFECT OF AMOXICILLIN ON SALIVARY NITRITE CONCENTRATIONS - AN IMPORTANT MECHANISM OF ADVERSE REACTIONS

Broad spectrum antibiotics are known to predispose towards oral candid iasis and gastroenteritis. Oral nitrite synthesis by commensal bacteri a may be important in protecting the mouth and lower intestine from pa thogenic organisms, including Candida albicans. The effect of 2 days a dministration of the broad spectrum antibiotic amoxycillin on salivary nitrite concentration, following a 200 mg potassium nitrate oral load , was studied in 10 healthy volunteers. The C-max fell by 40% and the AUC was reduced by 1227 mu M h (43%, 95% CI 273, 2181, P < 0.006) in t he antibiotic treated group when compared with control. These findings suggest that destruction of nitrate reductase containing bacteria in the mouth by antibiotics may explain an increased incidence of infecti on with Candida and other pathogens.