What is the treatment for pneumonia?

Treatment of Pneumonia

For community-acquired pneumonia (CAP) managed in the community, amoxicillin at higher doses is the preferred first-line agent, with macrolides (erythromycin or clarithromycin) as alternatives for penicillin-allergic patients. 1

Community Treatment (Outpatient)

• Amoxicillin remains the preferred antibiotic for outpatient management of mild CAP, targeting the most common pathogen Streptococcus pneumoniae 1, 2
• Macrolides (erythromycin or clarithromycin) are the alternative choice for patients with penicillin hypersensitivity 1
• Treatment duration is 7 days for uncomplicated pneumonia 1, 2
• For patients with life-threatening illness or anticipated delays >2 hours in hospital admission, general practitioners should administer antibiotics immediately 1

Hospitalized Patients with Non-Severe CAP

Combined oral therapy with amoxicillin plus a macrolide (erythromycin or clarithromycin) is preferred for patients requiring hospital admission for clinical reasons 1

Oral Therapy Approach:

• Most hospitalized patients with non-severe CAP can be adequately treated with oral antibiotics 1
• Amoxicillin monotherapy is appropriate for: (1) previously untreated patients in the community, or (2) elderly/socially isolated patients admitted for non-clinical reasons who would otherwise be treated at home 1
• Macrolide monotherapy may be suitable for patients who failed adequate amoxicillin therapy prior to admission, though combination therapy remains preferred 1

Parenteral Therapy When Oral Route Contraindicated:

• Intravenous ampicillin or benzylpenicillin plus erythromycin or clarithromycin 1
• Fluoroquinolones (levofloxacin) are alternative options for patients intolerant of penicillins/macrolides or with concerns about Clostridium difficile diarrhea, but are not first-line agents 1

Hospitalized Patients with Severe CAP

Patients with severe pneumonia require immediate parenteral antibiotics upon diagnosis 1

Preferred Regimen:

• Intravenous combination of a broad-spectrum β-lactamase stable antibiotic (co-amoxiclav, cefuroxime, cefotaxime, or ceftriaxone) plus a macrolide (clarithromycin or erythromycin) 1, 2
• This combination is also recommended for hospitalized patients with suspected bacterial CAP without risk factors for resistant bacteria 3

Alternative for β-lactam/Macrolide Intolerance:

• Fluoroquinolone with enhanced S. pneumoniae activity (levofloxacin) plus intravenous benzylpenicillin for patients intolerant of β-lactams or macrolides 1

Duration:

• 10 days for severe microbiologically undefined pneumonia 1, 2
• 14-21 days if legionella, staphylococcal, or gram-negative enteric bacilli are suspected or confirmed 1, 2

Nosocomial Pneumonia

• Combination therapy with extended-spectrum penicillin or cephalosporin plus an aminoglycoside is commonly employed 1
• For Pseudomonas aeruginosa as documented or presumptive pathogen, combination therapy with an anti-pseudomonal β-lactam is recommended 4
• Initial therapy must target suspected pathogens based on local hospital susceptibility patterns 1

Route of Administration and Transition

• Oral route is recommended for non-severe pneumonia in hospitalized patients without contraindications 1
• Transition from IV to oral therapy when clinical improvement occurs and temperature has been normal for 24 hours 1, 2
• Review route of administration daily, initially on the "post take" round 1

Treatment Failure (Non-Response After 48-72 Hours)

Conduct careful clinical review of history, examination, prescription chart, and all investigation results by an experienced clinician 1, 5

Further Investigations:

• Repeat chest radiograph, C-reactive protein, white cell count, and additional microbiological specimens 1, 5

Antibiotic Adjustment:

• For non-severe pneumonia on amoxicillin monotherapy: Add or substitute a macrolide to cover atypical pathogens 1, 5, 2
• For non-severe pneumonia on combination therapy: Consider changing to a fluoroquinolone with effective pneumococcal coverage 1, 5
• For severe pneumonia not responding to combination therapy: Consider adding rifampicin 1, 5

Special Populations

Pregnancy:

• Oral amoxicillin is first-line for mild pneumonia 2
• For severe pneumonia: IV β-lactamase stable antibiotic (co-amoxiclav, cefuroxime, or ceftriaxone) plus macrolide (clarithromycin or erythromycin) 2
• Avoid fluoroquinolones unless benefits outweigh risks 2
• Amphotericin B is the antifungal of choice; azoles are teratogenic 2

Follow-Up

• Clinical review at 6 weeks with general practitioner or hospital clinic for all patients 1, 5
• Chest radiograph at 6 weeks for patients with persistent symptoms/signs or high risk of malignancy (smokers, age >50) 1, 5
• Chest radiograph need not be repeated before hospital discharge in patients with satisfactory clinical recovery 1

Common Pitfalls

• Delayed antibiotic initiation increases mortality 5
• Failure to recognize extrapulmonary infection can contribute to persistent symptoms 5
• Consider non-infectious causes (heart failure, atelectasis, pulmonary embolism) for persistent radiographic abnormalities 5
• Monitor for C. difficile-associated diarrhea with broad-spectrum antibiotics 5, 6
• Some Pseudomonas aeruginosa isolates develop resistance rapidly during fluoroquinolone therapy; periodic culture and susceptibility testing is important 4