The Food and Drug Administration has cleared the expanded use of a procalcitonin test to help determine antibiotic use in patients with lower respiratory tract infections (LRTI) and sepsis.

The Vidas Brahms PCT Assay (bioMérieux) uses procalcitonin levels to determine whether a patient with a lower respiratory tract infection (LRTI) should begin or remain on antibiotics and when antibiotics should be withdrawn in a patient with sepsis.

“Unnecessary antibiotic use may contribute to the rise in antibiotic-resistant infections [and] this test may help clinicians make antibiotic treatment decisions,” Alberto Gutierrez, PhD , director of the FDA’s Office of In Vitro Diagnostics and Radiological Health, said in a statement.

The test will be used primarily in hospital settings and emergency departments, according to the FDA. Test levels that are high levels suggest bacterial infection and the need for antibiotics while low levels indicate viral or noninfectious processes. However, concerns exist regarding false-positive or false-negative test results, which can prompt clinicians to prematurely stop or unnecessarily continue an antibiotic regimen in certain patients.

“Health care providers should not rely solely on PCT test results when making treatment decisions but should interpret test results in the context of a patient’s clinical status and other laboratory results,” according to the FDA statement .

The expanded use of the test was approved based on promising data from clinical trials that was presented at an FDA advisory committee meeting in November 2016. The Vidas Brahms test was already approved by the FDA for use in determining a patient’s risk of dying from sepsis. The test was cleared via the FDA 510(k) regulatory pathway, which is meant for tests or devices for which there is already something similar on the market.

Support for the test’s expanded usage comes from published prospective, randomized clinical trials that compared PCT-guided therapy with standard therapy. In those studies, patients who had received PCT-guided therapy experienced significant decreases in antibiotic use without significant affects to their safety.