The study did confirm that PPIs could cause false negative or equivocal UBT results. Following administration of citrate to lower gastric pH results improved. The authors conclude that pre-test oral citrate solution improves UBT results in patients taking PPIs. Furthermore, since the mechanism appears to be pH related, they speculate it may be possible to design a UBT protocol that entirely eliminates false negative results in patients using acid suppressive therapies. This important study points out the major limitation of the UBT, that is, interference by concomitant medications such as PPIs, antibiotics, and bismuth compounds.
Similar limitations hold for stool antigen testing.
Until testing protocols are developed to circumvent this limitation, offending medications need to be discontinued for at least 1 week prior to testing to ensure accurate results. David A. Peura, M.D. Professor of Medicine Associate Chief Division of Gastroenterology and Hepatology University of Virginia Health Science Center Charlottesville, Virginia Click here to print this page.