Red Flags
- Sepsis with shock (SBP <90 despite fluids, lactate ≥4) — empirical broad-spectrum antimicrobials within 1 hour after blood cultures[1]
- Suspected bacterial meningitis (fever, headache, neck stiffness, altered mental status) — empirical ceftriaxone + vancomycin + ampicillin (if age >50) within 1 hour after CSF/blood cultures[1]
- Necrotising soft tissue infection (pain out of proportion, crepitus, skin necrosis) — emergent surgical exploration plus broad-spectrum antimicrobials[1]
- Healthcare-associated infection in patient with prior carbapenem exposure or MDR colonisation — narrow last-line agents (colistin, polymyxin B) and ID consult[1]
First-line treatment
Interventions
- Stewardship: review at 48–72 h[1]De-escalate to narrowest effective agent based on culture results; shorten duration; transition IV to PO; stop on resolution
- Source control[1]Drain abscesses, remove infected lines/devices, debride necrotic tissue, treat obstruction — antimicrobials alone fail without source control
First-line drug therapy
| Drug | Class | Adult | Paediatric | Notes |
|---|---|---|---|---|
| Amoxicillin-clavulanate[1] | Aminopenicillin + beta-lactamase inhibitor | 625 mg PO TID or 1.2 g IV TDS for 5–7 days | 25–45 mg/kg/day divided BD/TID (amoxicillin component) | Community-acquired LRTI, mild SSTI, animal bite, otitis media |
| Ceftriaxone[1] | 3rd-generation cephalosporin | 1–2 g IV daily (2 g BD for meningitis) | 50–100 mg/kg/day | Community-acquired pneumonia (severe), pyelonephritis, gonorrhoea, meningitis (with vancomycin) |
| Piperacillin-tazobactam[1] | Antipseudomonal beta-lactam-inhibitor combination | 4.5 g IV q8h (extended infusion preferred) | 300 mg/kg/day divided q6h | Hospital-acquired pneumonia, intra-abdominal infection, sepsis with abdominal source, neutropenic fever |
| Meropenem[1] | Carbapenem | 1 g IV q8h (extended infusion 3 h preferred) | 20–40 mg/kg/dose q8h | Reserve antibiotic — ESBL-producing organisms, severe HAP, septic shock with high MDR risk; de-escalate based on susceptibility |
| Vancomycin[1] | Glycopeptide | 15–20 mg/kg IV q8–12h, target trough 15–20 mg/L for severe MRSA | 10–15 mg/kg q6h | Suspected/confirmed MRSA, VRE-active alternative is linezolid, severe SSTI requiring IV |
Amoxicillin-clavulanate[1]
Aminopenicillin + beta-lactamase inhibitor
- Adult
- 625 mg PO TID or 1.2 g IV TDS for 5–7 days
- Paediatric
- 25–45 mg/kg/day divided BD/TID (amoxicillin component)
Community-acquired LRTI, mild SSTI, animal bite, otitis media
Ceftriaxone[1]
3rd-generation cephalosporin
- Adult
- 1–2 g IV daily (2 g BD for meningitis)
- Paediatric
- 50–100 mg/kg/day
Community-acquired pneumonia (severe), pyelonephritis, gonorrhoea, meningitis (with vancomycin)
Piperacillin-tazobactam[1]
Antipseudomonal beta-lactam-inhibitor combination
- Adult
- 4.5 g IV q8h (extended infusion preferred)
- Paediatric
- 300 mg/kg/day divided q6h
Hospital-acquired pneumonia, intra-abdominal infection, sepsis with abdominal source, neutropenic fever
Meropenem[1]
Carbapenem
- Adult
- 1 g IV q8h (extended infusion 3 h preferred)
- Paediatric
- 20–40 mg/kg/dose q8h
Reserve antibiotic — ESBL-producing organisms, severe HAP, septic shock with high MDR risk; de-escalate based on susceptibility
Vancomycin[1]
Glycopeptide
- Adult
- 15–20 mg/kg IV q8–12h, target trough 15–20 mg/L for severe MRSA
- Paediatric
- 10–15 mg/kg q6h
Suspected/confirmed MRSA, VRE-active alternative is linezolid, severe SSTI requiring IV
Safety-net
- Take antibiotics only as prescribed; complete the course only when your clinician advises — many infections need shorter courses than historically given[1]
- Watch for severe diarrhoea, rash, jaundice, or breathing difficulty during antibiotic therapy — same-day medical review[1]
- Worsening symptoms despite 48–72 h of antibiotic — return for review; may need different agent[1]
Referral criteria
- Sepsis with shock or end-organ failureICU/HDU; infectious diseases for tailored therapy[1]
- Suspected MDR organism (CRE, XDR-TB, C. auris, VRE)Infectious diseases / clinical microbiology for last-line agent selection[1]
- Recurrent or refractory infection despite appropriate first-lineInfectious diseases for source workup and resistance testing[1]
Clinical summary
ICMR-aligned empirical antimicrobial selection for common adult and paediatric clinical syndromes, with stewardship-based de-escalation.