Respirology31 August 2026

Pneumonia

Community-acquired pneumonia. INESSS adult and child GUOs.

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Hospitalization

INESSS Institut national d'excellence en santé et services sociaux

Decision	Guideline
Hospitalization	CRB-65 score Confusion, respiratory rate ≥30, systolic BP <90 or diastolic ≤60, age ≥65. CRB-65 = 0: home treatment. CRB-65 = 1: hospital unless only point is age ≥65, then clinical judgment. CRB-65 = 2–4: hospital. INESSS adult pneumonia GUO opens in a new tab

Diagnose

Clinical + imaging

INESSS Institut national d'excellence en santé et services sociaux

Decision	Guideline
Clinical diagnosis	Cough + focal signs or systemic infection Acute cough AND at least one focal respiratory sign (rales, rhonchi, egophony, dullness) OR signs of systemic infection (fever, chills, malaise). Tachypnea thresholds: <2 months 60 2–12 months 50 1–5 years 40 >5 years 30 INESSS adult pneumonia GUO opens in a new tab
Chest X-ray	Strongly recommended if diagnostic doubt X-ray not essential if diagnosis clinically obvious (INESSS default). CWC stricter: X-ray for all suspected pneumonia. INESSS adult pneumonia GUO opens in a new tab

Treat

First-line antibiotics

Fluoroquinolones last resort. Open the INESSS adult pneumonia GUO for penicillin-allergy algorithms. To reassess a penicillin label, see Penicillin allergy.

Community-acquired pneumonia — adults
Drug	Dose	Duration
First-line — healthy
Clarithromycin	500 mg PO BID	7 days
Clarithromycin XL	1000 mg PO DIE	7 days
Azithromycin	500 mg PO day 1, then 250 mg DIE	5 days
Doxycycline	100 mg PO BID	7 days
Amoxicillin (high-dose)	1000 mg PO TID	7 days
First-line — comorbidities or recent antibiotics
Amoxicillin plus macrolide or Doxycycline	Amoxicillin 1000 mg PO TID + clarithromycin 500 mg BID, clarithromycin XL 1000 mg DIE, azithromycin 500 then 250, or Doxycycline 100 mg BID	7 days (azithromycin 5)
Amox-clav 7:1 plus macrolide or Doxycycline	875/125 mg PO BID + same companion	7 days (azithromycin 5)
Last resort
Levofloxacin 500 mg	500 mg PO DIE	7 days
Levofloxacin 750 mg	750 mg PO DIE	5 days
Moxifloxacin	400 mg PO DIE	7 days

Children 3 months and older

High-dose Amoxicillin

INESSS Institut national d'excellence en santé et services sociaux

Decision	Guideline
First-line	High-dose Amoxicillin 7–10 days 90 mg/kg/day divided TID (max 1000 mg/dose). BID if adherence is at risk. CPS comparison: 5-day course. INESSS child pneumonia GUO opens in a new tab

Community-acquired pneumonia — child ≥3 months, INESSS
Drug	Dose	Duration
Presumed bacterial
Amoxicillin	90 mg/kg/day PO divided TID (max 1000 mg/dose)	7–10 days
Last 30 days or not Hib-vaccinated
Amox-clav 7:1	90 mg/kg/day PO divided TID (max 1000 mg TID)	7–10 days
Presumed atypical
Clarithromycin	15 mg/kg/day PO divided BID (max 500 mg/dose)	7–10 days
Azithromycin	10 mg/kg day 1, then 5 mg/kg DIE × 4 (max 500 then 250 mg)	5 days

Follow-up

INESSS Institut national d'excellence en santé et services sociaux

Decision	Guideline
No improvement	No improvement, or worsening of symptoms and signs, after 72 h of treatment suggests a change of antibiotic or hospitalization according to the severity of the pneumonia. INESSS adult pneumonia GUO opens in a new tab
Persistent fever	If fever persists more than 48 to 72 hours after the start of treatment, or if there is clinical deterioration: reassess the patient and repeat the radiograph to look for complications that would require hospitalization. INESSS child pneumonia GUO opens in a new tab

Reviewed 31 August 2026 against the official sources below.

Sources

Blue square: Québec. The code names the body; each section's key gives its full name.

	INESSS adult pneumonia GUO opens in a new tab
	INESSS child pneumonia GUO opens in a new tab