Empirical therapy for moderate-severity CAP in adults in tropical regions of Australia
In tropical regions of Australia1, the gram-negative bacteria Burkholderia pseudomallei (which causes melioidosis) and Acinetobacter baumannii can cause community-acquired pneumonia (CAP); cases are also occasionally seen further south. Follow local protocols, if available. In the absence of local protocols, the following regimens may be appropriate.
Patients with moderate-severity CAP in a tropical region of Australia are managed as for patients in nontropical regions, unless the patient has risk factors for B. pseudomallei or A. baumannii, such as diabetes, excessive alcohol use, chronic kidney or lung disease, and immunosuppressive therapy (including chronic corticosteroid use)Davis, 2014Smith, 2018. For patients who have risk factors, replace the empirical therapy regimen with:
ceftriaxone 2 g intravenously, daily. See advice on patient review, intravenous to oral switch and duration of therapy. ceftriaxone ceftriaxone ceftriaxone
If A. baumannii is suspected based on local epidemiology, add to the above regimen:
gentamicin intravenously; see Gentamicin initial dose calculator for adults for initial dose. See Principles of aminoglycoside use for prescribing considerations and subsequent dosing. gentamicin gentamicin gentamicin
For patients who have had a nonsevere (immediate or delayed) hypersensitivity reaction to a penicillin, use the ceftriaxone-based regimen at the dosage above.
For patients who have had a severe immediate2 hypersensitivity reaction to a penicillin, the ceftriaxone-based regimen (at the dosages above) can be considered if a beta-lactam antibiotic is strongly preferred (for considerations, see Severe immediate hypersensitivity: Implications of cross-reactivity between penicillins and cephalosporins).
For patients who have had a severe immediate2 hypersensitivity reaction to a penicillin in whom the ceftriaxone-based regimen is not used, or for patients who have had a severe delayed3 hypersensitivity reaction to a penicillin, replace ceftriaxone with:
moxifloxacin 400 mg orally or enterally, daily. For dosage adjustment in adults with kidney impairment, see moxifloxacin dosage adjustment. See advice on patient review and duration of therapy. moxifloxacin moxifloxacin moxifloxacin
If an atypical pathogen4 (eg Mycoplasma pneumoniae, Chlamydophila [Chlamydia] pneumoniae, Legionella species) is suspected based on epidemiology, add to the above regimens:
1doxycycline 100 mg orally, 12-hourly. The usual duration of therapy is 5 days; see advice on patient review and duration of therapy doxycycline doxycycline doxycycline
OR
2azithromycin 500 mg orally, daily for 3 days. See advice on patient review azithromycin azithromycin azithromycin
OR
2clarithromycin 500 mg orally, 12-hourly. For dosage adjustment in adults with kidney impairment, see clarithromycin dosage adjustment. The usual duration of therapy is 5 days; see advice on patient review and duration of therapy. clarithromycin clarithromycin clarithromycin
If B. pseudomallei pneumonia is confirmed, see Melioidosis for ongoing management. If A. baumannii pneumonia or another pathogen is confirmed, see Directed therapy for pneumonia for ongoing management.