Duration of Antibiotic Therapy for Pleural Infection

Oral antibiotics should be given at discharge for 1-4 weeks for pleural infections, but should be extended if there is residual disease. 1, 2

Initial Antibiotic Selection

All cases of pleural infection should be treated with intravenous antibiotics initially and must include coverage for Streptococcus pneumoniae 1
Broader spectrum coverage is required for hospital-acquired infections, as well as those secondary to surgery, trauma, and aspiration 1, 2
Where possible, antibiotic choice should be guided by microbiological results 1
Aminoglycosides should be avoided due to poor penetration into the pleural space 2

For community-acquired pneumonia with pleural infection, the recommended duration is 1-4 weeks of oral antibiotics after hospital discharge 2
If residual disease is present, antibiotic therapy should be extended beyond the standard duration 1, 2
For complicated parapneumonic effusions or adequately drained empyemas, some experts recommend treatment for 7-10 days after fever resolution, while others recommend therapy for up to 4-6 weeks 2
Recent evidence from the SLIM trial suggests that shorter courses (14-21 days total) may be as effective as longer courses (28-42 days) in medically treated adult patients with pleural infection who have been stabilized within 14 days of admission 3

Patients should demonstrate clinical and laboratory signs of improvement within 48-72 hours of starting appropriate treatment before transitioning to oral therapy 2
Improvement criteria include decreased fever, reduced cough, decreased tachypnea, reduced supplemental oxygen dependence, and increased activity and appetite 2
For adults with severe hospital-acquired pneumonia with pleural infection, if combination therapy with an aminoglycoside-containing regimen is used, the aminoglycoside can be stopped after 5-7 days in responding patients 1

Most antibiotics tested (amoxicillin, metronidazole, piperacillin-tazobactam, clindamycin) reach pleural fluid levels equivalent to blood levels and well above minimum inhibitory concentrations, with the exception of co-trimoxazole which has poor penetration 4
Anaerobic bacteria are a major cause of pleural infection, so anaerobic coverage in antibiotic regimens is mandatory 5
For children under 5 years old, amoxicillin is the first choice for oral antibiotic therapy 2
For adults and children over 5 years old, oral amoxicillin (90 mg/kg/day in 2 doses up to a maximum of 4 g/day) is the treatment of choice 2

The key components of managing pleural infection are appropriate antimicrobial therapy and chest-tube drainage 5
Effusions that are enlarging and/or compromising respiratory function should not be managed by antibiotics alone 1
Early active treatment should be considered as conservative treatment results in prolonged duration of illness and hospital stay 1
Management of pleural infection typically requires prolonged hospitalization (average 14 days) 5

Positive cultures are only obtained in 56% of cases, so empirical antibiotics should provide Gram-positive, Gram-negative, and anaerobic coverage 6
Pleural infection carries significant mortality and morbidity rates reaching upwards of 50% if not properly managed 7
When using ceftriaxone, be aware that it must not be administered simultaneously with calcium-containing IV solutions, especially in neonates 8
The duration of antibiotic treatment depends on adequate drainage and demonstrated clinical response for each patient 2