Procalcitonin Guidance of Antibiotic Therapy in Community-acquired Pneumonia

TLDR

Community‑acquired pneumonia guidelines recommend 7–21 days of antibiotics, but procalcitonin is elevated in bacterial infections and its dynamics may predict outcomes. This study aimed to evaluate whether procalcitonin‑guided initiation and duration of antibiotics improves treatment in community‑acquired pneumonia. In a randomized trial of 302 patients, 151 received antibiotics guided by procalcitonin thresholds (<0.1 µg/L discouraged, <0.25 µg/L discouraged, >0.25 µg/L encouraged, >0.5 µg/L strongly encouraged) while 151 followed usual practice, with data collected at baseline, days 4, 6, 8 and week 6. Procalcitonin guidance reduced antibiotic exposure by 48 % (RR 0.52), lowered admission prescriptions, cut median treatment duration from 12 to 5 days, increased discontinuation hazard (HR 3.2), yet overall success remained 83 %.

Abstract

Rationale: In patients with community-acquired pneumonia, guidelines recommend antibiotic treatment for 7 to 21 d. Procalcitonin is elevated in bacterial infections, and its dynamics have prognostic implications.Objective: To assess procalcitonin guidance for the initiation and duration of antibiotic therapy in community-acquired pneumonia.Methods: In a randomized intervention trial, 302 consecutive patients with suspected community-acquired pneumonia were included. Data were assessed at baseline, after 4, 6, and 8 d, and after 6 wk.The control group (n = 151) received antibiotics according to usual practice. In the procalcitonin group (n = 151), antibiotic treatment was based on serum procalcitonin concentrations as follows: strongly discouraged, less than 0.1 μg/L; discouraged, less than 0.25 μg/L; encouraged, greater than 0.25 μg/L; strongly encouraged, greater than 0.5 μg/L. The primary endpoint was antibiotic use; secondary endpoints were measures of clinical, laboratory, and radiographic outcome.Results: At baseline, both groups were similar regarding clinical, laboratory, and microbiology characteristics, and Pneumonia Severity Index. Procalcitonin guidance reduced total antibiotic exposure (relative risk, 0.52; 95% confidence interval, 0.48–0.55; p < 0.001), antibiotic prescriptions on admission (85 vs. 99%; p < 0.001), and antibiotic treatment duration (median, 5 vs. 12 d; p < 0.001) compared with patients treated according to guidelines. After adjustment for Pneumonia Severity Index, the hazard ratio of antibiotic discontinuation was higher in the procalcitonin group than in the control group (3.2; 95% confidence interval, 2.5 to 4.2). Outcome was similar in both groups, with an overall success rate of 83%.Conclusions: Procalcitonin guidance substantially reduces antibiotic use in community-acquired pneumonia. These findings may have important clinical and public health implications.