Community-acquired pneumonia

Red Flags

CAP with septic shock or respiratory failure — ICU; broad-spectrum empirical within 1 hour^[1]
CURB-65 ≥3 — admit; ICU consideration if other major or 3 minor severity criteria^[1]
Cavitation or non-resolving CAP — exclude pulmonary TB (sputum GeneXpert), structural lung disease, malignancy^[1]
CAP in immunocompromised host — opportunistic pathogens (PCP, fungi, atypical mycobacteria); empirical broad cover plus ID consult^[1]

First-line treatment

Interventions

Vaccination^[1]
Pneumococcal (PCV13/PPSV23) for ≥65 years and high-risk; annual influenza; COVID-19

First-line drug therapy

Drug	Class	Adult	Paediatric	Notes
Amoxicillin^[1]	Aminopenicillin	1 g PO TID for 5 days	80–90 mg/kg/day divided BD/TID	Outpatient CAP without comorbidities
Amoxicillin-clavulanate plus azithromycin^[1]	Beta-lactam-inhibitor + macrolide	Amoxicillin-clavulanate 625 mg PO TID + azithromycin 500 mg PO daily × 5 days	Weight-based	Outpatient CAP with comorbidities (DM, COPD, CKD); covers atypicals
Ceftriaxone + azithromycin (inpatient non-ICU)^[1]	3rd-gen cephalosporin + macrolide	Ceftriaxone 1–2 g IV daily plus azithromycin 500 mg IV/PO daily for 5–7 days	Ceftriaxone 50 mg/kg/day	Standard inpatient regimen; respiratory fluoroquinolone alternative monotherapy in penicillin allergy
Piperacillin-tazobactam + azithromycin (severe CAP / ICU)^[1]	Antipseudomonal beta-lactam-inhibitor + macrolide	Piperacillin-tazobactam 4.5 g IV q8h + azithromycin 500 mg IV daily; add MRSA cover (vancomycin or linezolid) if cavitation, post-influenza, IV drug use	—	Severe CAP requiring ICU; structural lung disease or prior MDR colonisation drives Pseudomonas cover
Oseltamivir (when influenza co-suspected)^[1]	Neuraminidase inhibitor	75 mg PO BD × 5 days	Weight-based	Add during influenza season

Amoxicillin^[1]

Aminopenicillin

Adult: 1 g PO TID for 5 days
Paediatric: 80–90 mg/kg/day divided BD/TID

Outpatient CAP without comorbidities

Amoxicillin-clavulanate plus azithromycin^[1]

Beta-lactam-inhibitor + macrolide

Adult: Amoxicillin-clavulanate 625 mg PO TID + azithromycin 500 mg PO daily × 5 days
Paediatric: Weight-based

Outpatient CAP with comorbidities (DM, COPD, CKD); covers atypicals

Ceftriaxone + azithromycin (inpatient non-ICU)^[1]

3rd-gen cephalosporin + macrolide

Adult: Ceftriaxone 1–2 g IV daily plus azithromycin 500 mg IV/PO daily for 5–7 days
Paediatric: Ceftriaxone 50 mg/kg/day

Standard inpatient regimen; respiratory fluoroquinolone alternative monotherapy in penicillin allergy

Piperacillin-tazobactam + azithromycin (severe CAP / ICU)^[1]

Antipseudomonal beta-lactam-inhibitor + macrolide

Adult: Piperacillin-tazobactam 4.5 g IV q8h + azithromycin 500 mg IV daily; add MRSA cover (vancomycin or linezolid) if cavitation, post-influenza, IV drug use
Paediatric: —

Severe CAP requiring ICU; structural lung disease or prior MDR colonisation drives Pseudomonas cover

Oseltamivir (when influenza co-suspected)^[1]

Neuraminidase inhibitor

Adult: 75 mg PO BD × 5 days
Paediatric: Weight-based

Add during influenza season

Safety-net

Take antibiotics for the full prescribed course even when feeling better — usually 5 days outpatient^[1]
Worsening breathlessness, increasing chest pain, confusion, low urine output — same-day care^[1]
Persistent symptoms despite 48–72 h antibiotics — return for review; consider TB workup in non-resolving cases^[1]

Referral criteria

Severe CAP with septic shock or respiratory failureICU; broad-spectrum empirical including MRSA/Pseudomonas if risk factors^[1]
CURB-65 ≥3Hospital admission; ID consult if MDR risk^[1]
Pleural effusion >1 cm or empyema suspicionDiagnostic thoracentesis; respiratory medicine for chest drain^[1]
Failure to improve at 48–72 hReassess: cultures, atypicals, MDR, complication, TB co-infection, alternative diagnosis^[1]

Clinical summary

ICMR-aligned diagnosis and antimicrobial therapy of CAP in adults; severity-driven inpatient vs outpatient pathway with TB exclusion in endemic settings.

References

1.ICMR Treatment Guidelines for Community-Acquired Pneumonia (within ICMR Common Syndromes 2nd Edition); Indian Chest Society / NCCP CAP recommendations (2022)