Low- to moderate-severity Legionella pneumonia in adults
For low- to moderate-severity Legionella pneumonia in adults, useGershengorn, 2015Jasper, 2021Kato, 2021:
1azithromycin 500 mg orally or enterally, daily for 3 to 7 days. If the patient has low-severity pneumonia and has clinically improved, treat for 3 days. For other patients, treat for up to 7 days based on clinical response azithromycin azithromycin azithromycin
OR
2ciprofloxacin 750 mg orally or enterally, 12-hourly for 5 to 7 days; treat for 5 days if clinical response is rapid. For dosage adjustment in adults with kidney impairment, see ciprofloxacin oral dosage adjustment ciprofloxacin ciprofloxacin ciprofloxacin
OR
3doxycycline 100 mg orally or enterally, 12-hourly for 10 to 14 days1. doxycycline doxycycline doxycycline
Because quinolones are generally reserved for treatment of infections resistant to other drugs, and evidence is conflicting on whether antibiotic choice affects outcomes for Legionella pneumoniaJasper, 2021Kato, 2021, azithromycin is preferred to ciprofloxacin.
In addition, Legionella longbeachae isolates appear to be more resistant to doxycycline, in vitro, and there is a lack of clinical data on outcomes with doxycycline. Consider using azithromycin or ciprofloxacin for directed therapy of L. longbeachae pneumonia.
If oral therapy is not tolerated or there are concerns about absorption, consider giving azithromycin or ciprofloxacin intravenously (see dosage for high-severity Legionella pneumonia).
For management of patients who are not improving, see (as relevant):
- Approach to managing adults with CAP who are not improving
- Approach to managing patients with HAP who are not improving
- Approach to managing patients with VAP who are not improving.
General strategies to prevent further episodes of pneumonia are outlined in Prevention of CAP in adults. For strategies to prevent hospital-acquired pneumonia (HAP) or ventilator-associated pneumonia (VAP), see Prevention of HAP or Prevention of VAP.