The FDA has okayed the Vidas Brahms procalcitonin (PCT) test for the assessment of antibiotics in lower respiratory tract infections, reports Medscape.

High levels of PCT suggest a bacterial infection, whereas low levels suggest a viral infection or noninfectious causes, the FDA says. Clinicians may be able to use PCT levels and other information to safely withhold or discontinue antibiotics. PCT may indicate the presence of a variety of bacterial infections, but it does not detect the exact cause of a patient’s symptoms.

The Vidas Brahms PCT assay is already approved by the FDA to help clinicians better predict a patient’s risk of dying from sepsis or of their condition worsening.

The FDA cleared expanded use of the test to help clinicians assess whether antibiotic treatment should be started or stopped in patients with lower respiratory tract infections and stopped in patients with sepsis. The decision was based on clinical trial findings from published literature that compared PCT-guided therapy to standard therapy.