High-severity Legionella pneumonia in adults

For high-severity Legionella pneumonia in adults, useGershengorn, 2015Jasper, 2021Kato, 2021:

1azithromycin 500 mg intravenously, daily; see below for intravenous to oral switch and duration of therapy azithromycin azithromycin azithromycin

OR

2ciprofloxacin 400 mg intravenously, 8-hourly. For dosage adjustment in adults with kidney impairment, see ciprofloxacin intravenous dosage adjustment. See below for intravenous to oral switch and duration of therapy. ciprofloxacin ciprofloxacin ciprofloxacin

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.

For patients with high-severity Legionella pneumonia requiring intensive care support, combination therapy with azithromycin plus ciprofloxacin, or with rifampicin plus either azithromycin or ciprofloxacin, is sometimes used. There is limited evidence for this approach, and combination therapy has an increased potential for drug toxicity and significant drug interactions – seek expert advice.

Intravenous to oral switch: once the patient improves, switch to oral (or enteral) azithromycin or ciprofloxacin. For dosages, see low- to moderate-severity Legionella pneumonia. For guidance on when to switch to oral therapy, see Guidance for intravenous to oral switch.

Duration of therapy for high-severity disease: the optimal duration of therapy for high-severity Legionella pneumonia is uncertain. A total treatment duration of 7 to 10 days (intravenous + oral) is generally recommended. Some patients with immune compromise may require a longer duration of therapy – seek expert advice. Prolonged treatment (eg longer than 14 days) with azithromycin should generally be avoided because it has a long intracellular half-life.

For management of patients who are not improving, see (as relevant):

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.