In many cases the prescription of antibiotics is not indicated. Especially in lower respiratory tract infections (LRTI) the infection is predominantly of viral origin. However 75% of the patients are treated with antibiotics. In critically ill patients with sepsis, severe sepsis, or severe bacterial infections, like pneumonia, the duration of the antibiotic therapy is often longer than indicated and could be stopped earlier without any adverse impact on the patient. This antibiotic overuse contributes to increasing antimicrobial resistance, increased risk of drug-related adverse events and higher medical costs. The use of a sensitive B·R·A·H·M·S PCT assay, like PATHFASTTM B·R·A·H·M·S PCT, for determining the necessary and optimal duration of antibiotic therapy is shown in Figure 1 . The sensitivity PATHFASTTM B·R·A·H·M·S PCT assay allows to measure low concentrations (<0.1 ng/ml) of PCT thus allowing to detect LRTI.