Treatment algorithm

Please note that formulations/routes and doses may differ between drug names and brands, drug formularies, or locations. Treatment recommendations are specific to patient groups: see disclaimer

ACUTE

outpatient

1st line – oral amoxicillin, doxycycline, or a macrolide

Back
ACUTE
|
outpatient
|
without comorbidities or risk factors for drug-resistant pathogens
1st line – 

oral amoxicillin, doxycycline, or a macrolide

Outpatient treatment is recommended in patients with Pneumonia Severity Index (PSI) risk class I or II with a PSI score ≤70 (low risk), or a CURB-65 score of 0-1 (low severity).[88][89] PSI is preferred over CURB-65.[18][91]

Empiric oral antibiotics are recommended: amoxicillin, doxycycline, or a macrolide (e.g., azithromycin or clarithromycin). Only use a macrolide in areas with pneumococcal resistance to macrolides <25% and when there are contraindications to alternative therapies.[18]

Treat for a minimum of 5 days. Duration of treatment should be guided by a validated measure of clinical stability (e.g., resolution of vital sign abnormalities, normal cognitive function, ability to eat).[18][116][117] Consider discontinuing treatment when the patient has been afebrile for 48-72 hours and there are no signs of complications (endocarditis, meningitis).[18][116]

Reassess patients at 48 hours. Symptoms should improve within this time with appropriate treatment. Consider hospital admission in patients who fail to improve within 48 hours.

Consider switching patients to an organism-specific antimicrobial therapy guided by antibiotic sensitivity in patients in whom laboratory tests have revealed a causative organism.

Primary options

amoxicillin: 1000 mg orally three times daily

OR

doxycycline: 100 mg orally twice daily

Secondary options

azithromycin: 500 mg orally once daily on the first day, followed by 250 mg once daily thereafter

OR

clarithromycin: 500 mg orally (immediate-release) twice daily; 1000 mg orally (extended-release) once daily

Plus – supportive care

Back
ACUTE
|
outpatient
|
without comorbidities or risk factors for drug-resistant pathogens
Plus – 

supportive care

Treatment recommended for ALL patients in selected patient group

Advise patients not to smoke, to rest, and to stay well hydrated.

Consider – influenza antiviral cover

Back
ACUTE
|
outpatient
|
without comorbidities or risk factors for drug-resistant pathogens
Consider – 

influenza antiviral cover

Treatment recommended for SOME patients in selected patient group

Consider antiviral therapy (e.g., oseltamivir) in outpatients who test positive for influenza virus.[18]

Primary options

oseltamivir: 75 mg orally twice daily for 5 days

1st line – oral combination antibiotic therapy or fluoroquinolone monotherapy

Back
ACUTE
|
outpatient
|
with comorbidities or risk factors for drug-resistant pathogens
1st line – 

oral combination antibiotic therapy or fluoroquinolone monotherapy

Outpatient treatment is recommended in patients with Pneumonia Severity Index (PSI) risk class I or II with a PSI score ≤70 (low risk), or a CURB-65 score of 0-1 (low severity).[88][89] PSI is preferred over CURB-65.[18][91]

Comorbidities include: chronic heart, lung, liver, or renal disease; diabetes mellitus; alcohol abuse; malignancy; asplenia. Broader-spectrum antibiotic regimens are required in these patients as many will have risk factors for drug-resistant pathogens (e.g., recent hospitalization and administration of parenteral antibiotics in the past 90 days), and they are more vulnerable to poor outcomes if the empiric regimen is inadequate.[18]

Empiric oral antibiotics are recommended: combination therapy with amoxicillin/clavulanate or a cephalosporin (e.g., cefpodoxime, cefuroxime) plus a macrolide or doxycycline; or monotherapy with a respiratory fluoroquinolone (e.g., levofloxacin, moxifloxacin). These regimens should effectively cover drug-resistant pathogens.[18]

Consider safety issues before prescribing fluoroquinolones. The Food and Drug Administration (FDA) has warned about the increased risk of aortic dissection, significant hypoglycemia, and mental health adverse effects.[112][113] The European Medicines Agency (EMA) completed a review of serious, disabling, and potentially irreversible adverse effects associated with fluoroquinolones in 2018. These adverse effects included tendonitis, tendon rupture, arthralgia, neuropathies, and other musculoskeletal or nervous system effects.[114] Despite these concerns, American Thoracic Society (ATS)/Infectious Diseases Society of America (IDSA) guidelines still recommend fluoroquinolones as an option in patients with low-severity CAP who have comorbidities and are managed in the outpatient setting.[18]

Treat for a minimum of 5 days. Duration of treatment should be guided by a validated measure of clinical stability (e.g., resolution of vital sign abnormalities, normal cognitive function, ability to eat).[18][116][117] Consider discontinuing treatment when the patient has been afebrile for 48-72 hours and there are no signs of complications (endocarditis, meningitis).[18][116]

Reassess patients at 48 hours. Symptoms should improve within this time with appropriate treatment. Consider hospital admission in patients who fail to improve within 48 hours.

Consider switching patients to an organism-specific antimicrobial therapy guided by antibiotic sensitivity in patients in whom laboratory tests have revealed a causative organism.

Primary options

amoxicillin/clavulanate: 500 mg orally (immediate-release) three times daily; 875 mg orally (immediate-release) twice daily; 2000 mg orally (extended-release) twice daily

More

or

cefpodoxime proxetil: 200 mg orally twice daily

or

cefuroxime axetil: 500 mg orally twice daily

-- AND --

azithromycin: 500 mg orally once daily on the first day, followed by 250 mg once daily thereafter

or

clarithromycin: 500 mg orally (immediate-release) twice daily; 1000 mg orally (extended-release) once daily

or

doxycycline: 100 mg orally twice daily

OR

levofloxacin: 750 mg orally once daily

OR

moxifloxacin: 400 mg orally once daily

Plus – supportive care

Back
ACUTE
|
outpatient
|
with comorbidities or risk factors for drug-resistant pathogens
Plus – 

supportive care

Treatment recommended for ALL patients in selected patient group

Advise patients not to smoke, to rest, and to stay well hydrated.

Consider – influenza antiviral cover

Back
ACUTE
|
outpatient
|
with comorbidities or risk factors for drug-resistant pathogens
Consider – 

influenza antiviral cover

Treatment recommended for SOME patients in selected patient group

Consider antiviral therapy (e.g., oseltamivir) in outpatients who test positive for influenza virus.[18]

Primary options

oseltamivir: 75 mg orally twice daily for 5 days

inpatient

1st line – intravenous combination antibiotic therapy or fluoroquinolone monotherapy

Back
ACUTE
|
inpatient
|
not in intensive care unit (nonsevere)
1st line – 

intravenous combination antibiotic therapy or fluoroquinolone monotherapy

Hospital admission is recommended in patients with a Pneumonia Severity Index (PSI) risk class III (these patients may benefit from a brief period of hospitalization), PSI risk class IV or V, or a CURB-65 score of 3.[88][89] PSI is preferred over CURB-65.[18][91]

Empiric intravenous antibiotics are recommended: combination therapy with a beta-lactam (e.g., ampicillin/sulbactam, cefotaxime, ceftriaxone, ceftaroline) plus a macrolide (e.g., azithromycin, clarithromycin); or monotherapy with a respiratory fluoroquinolone (e.g., levofloxacin, moxifloxacin). Consider combination therapy with a beta-lactam plus doxycycline in patients who have contraindications to both macrolides and fluoroquinolones. Note that clarithromycin is only available as an oral formulation in the US, and so can only be used if the oral route is feasible.

Consider safety issues before prescribing fluoroquinolones. The Food and Drug Administration (FDA) has warned about the increased risk of aortic dissection, significant hypoglycemia, and mental health adverse effects.[112][113] The European Medicines Agency (EMA) completed a review of serious, disabling, and potentially irreversible adverse effects associated with fluoroquinolones in 2018. These adverse effects included tendonitis, tendon rupture, arthralgia, neuropathies, and other musculoskeletal or nervous system effects.[114]

Treat for a minimum of 5 days. Duration of treatment should be guided by a validated measure of clinical stability (e.g., resolution of vital sign abnormalities, normal cognitive function, ability to eat).[18][116][117] Consider discontinuing treatment when the patient has been afebrile for 48-72 hours and there are no signs of complications (endocarditis, meningitis).[18][116]

Evaluate whether the patient can be switched to oral therapy on a daily basis; the switch should be made as soon as possible. Switch to an oral formulation of the same drug or an oral formulation of a drug within the same drug class.[18]

Consider switching patients to an organism-specific antimicrobial therapy guided by antibiotic sensitivity in patients in whom laboratory tests have revealed a causative organism.

Primary options

ampicillin/sulbactam: 1.5 to 3 g intravenously every 6 hours

More

or

cefotaxime: 1-2 g intravenously every 8 hours

or

ceftriaxone: 1-2 g intravenously every 24 hours

or

ceftaroline fosamil: 600 mg intravenously every 12 hours

-- AND --

azithromycin: 500 mg intravenously every 24 hours

or

clarithromycin: 500 mg orally (immediate-release) twice daily

OR

levofloxacin: 750 mg intravenously every 24 hours

OR

moxifloxacin: 400 mg intravenously every 24 hours

Consider – MRSA antibiotic cover

Back
ACUTE
|
inpatient
|
not in intensive care unit (nonsevere)
Consider – 

MRSA antibiotic cover

Treatment recommended for SOME patients in selected patient group

Additional empiric antibiotic cover is required in patients with risk factors for methicillin-resistant Staphylococcus aureus (MRSA) if locally validated risk factors are present.[18]

If the patient has a prior history of respiratory isolation of MRSA: add vancomycin or linezolid and obtain cultures (or nasal polymerase chain reaction [PCR] if available) to guide de-escalation or to confirm the need to continue additional cover.[18]

If the patient has had a recent hospitalization and parenteral antibiotics in the past 90 days, and has been locally validated for risk factors for MRSA: obtain cultures and nasal PCR. If PCR or cultures are negative, withhold additional cover. If PCR or cultures are positive, start additional cover.[18]

Consider de-escalation to standard antibiotic therapy at 48 hours provided cultures do not reveal a drug-resistant pathogen and the patient is clinically improving.[18]

A longer treatment course of 7 days is recommended in patients with MRSA.[18]

Primary options

vancomycin: 15 mg/kg intravenously every 12 hours; adjust dose based on serum vancomycin levels

OR

linezolid: 600 mg intravenously every 12 hours

Consider – Pseudomonas antibiotic cover

Back
ACUTE
|
inpatient
|
not in intensive care unit (nonsevere)
Consider – 

Pseudomonas antibiotic cover

Treatment recommended for SOME patients in selected patient group

Additional empiric antibiotic cover is required in patients with risk factors for Pseudomonas aeruginosa if locally validated risk factors are present.[18]

If the patient has a prior history of respiratory isolation of P aeruginosa: add piperacillin/tazobactam, cefepime, ceftazidime, aztreonam, meropenem, or imipenem/cilastatin, and obtain cultures to guide de-escalation or to confirm the need to continue additional cover.[18]

If the patient has had a recent hospitalization and parenteral antibiotics in the past 90 days, and has been locally validated for risk factors for P aeruginosa: obtain cultures but only initiate cover for P aeruginosa if cultures are positive.[18]

Consider de-escalation to standard antibiotic therapy at 48 hours provided cultures do not reveal a drug-resistant pathogen and the patient is clinically improving.[18]

A longer treatment course of 7 days is recommended in patients with P aeruginosa.[18]

Take the initial empiric regimen into account adding Pseudomonas cover so that two antibiotics from the same class are not used together.

Primary options

piperacillin/tazobactam: 4.5 g intravenously every 6 hours

More

OR

cefepime: 2 g intravenously every 8 hours

OR

ceftazidime sodium: 2 g intravenously every 8 hours

OR

imipenem/cilastatin: 500 mg intravenously every 6 hours

More

OR

meropenem: 1 g intravenously every 8 hours

OR

aztreonam: 2 g intravenously every 8 hours

Consider – Enterobacteriaceae antibiotic cover

Back
ACUTE
|
inpatient
|
not in intensive care unit (nonsevere)
Consider – 

Enterobacteriaceae antibiotic cover

Treatment recommended for SOME patients in selected patient group

Additional empiric antibiotic cover is required in patients with risk factors for extended-spectrum beta-lactamase-producing Enterobacteriaceae. Consult an infectious disease specialist for guidance on an appropriate antibiotic regimen.[18]

A longer treatment course is recommended in patients in cases of pneumonia due to less common pathogens.[18]

Consider – influenza antiviral cover

Back
ACUTE
|
inpatient
|
not in intensive care unit (nonsevere)
Consider – 

influenza antiviral cover

Treatment recommended for SOME patients in selected patient group

Add antiviral treatment (e.g., oseltamivir) to antimicrobial treatment in patients with CAP who test positive for influenza in the inpatient setting, independent of duration of illness before diagnosis.[18]

Primary options

oseltamivir: 75 mg orally twice daily for 5 days

Plus – supportive care

Back
ACUTE
|
inpatient
|
not in intensive care unit (nonsevere)
Plus – 

supportive care

Treatment recommended for ALL patients in selected patient group

Administer oxygen therapy as necessary. Monitor oxygen saturation and inspired oxygen concentration with the aim of maintaining SaO₂ above 92%. High concentrations of oxygen can safely be given in uncomplicated pneumonia. [ Cochrane Clinical Answers logo ] Patients with respiratory failure, despite appropriate oxygen therapy, require urgent airway management and possible intubation. Treatment of patients with COPD complicated by ventilatory failure oxygen therapy should be guided by repeated arterial blood gas measurements.[106]

Assess patients for volume depletion. Administer intravenous fluids if needed according to local protocols, and give nutritional support in prolonged illness.

Monitor temperature, respiratory rate, pulse, blood pressure, and mental status at least twice daily and more frequently in those with severe pneumonia or requiring regular oxygen therapy. Monitor C-reactive protein (CRP) levels regularly as they are a sensitive marker of progress in pneumonia. Repeat chest x-rays in patients who are not progressing satisfactorily. Routine follow-up chest imaging is not recommended if symptoms resolve within 5-7 days.[18]

1st line – intravenous combination antibiotic therapy

Back
ACUTE
|
inpatient
|
in intensive care unit (severe)
1st line – 

intravenous combination antibiotic therapy

Admit patients with hypotension requiring vasopressor therapy or respiratory failure requiring mechanical ventilation to the intensive care unit (ICU). In patients who do not require vasopressor therapy or mechanical ventilation, use the American Thoracic Society (ATS)/Infectious Diseases Society of America (IDSA) criteria for defining severe CAP (see Diagnostic criteria section) and clinical judgment to guide the need for higher levels of treatment intensity.[18][91] Admit patients with severe CAP (defined as one major criterion or three or more minor criteria) to the ICU.[18]

Start antibiotic therapy promptly as a delay in administration has been associated with an increased risk in mortality.[115]

Empiric intravenous antibiotics are recommended: combination therapy with a beta-lactam (e.g., ampicillin/sulbactam, cefotaxime, ceftriaxone, ceftaroline) plus a macrolide (e.g., azithromycin, clarithromycin); or combination therapy with a beta-lactam plus a respiratory fluoroquinolone (e.g., levofloxacin, moxifloxacin). There is stronger evidence for beta-lactam plus macrolide combination.[18] Although ATS/IDSA recommend clarithromycin in these patients, it is only available as an oral formulation in the US so is unlikely to be useful in this setting.

Consider safety issues before prescribing fluoroquinolones. The Food and Drug Administration (FDA) has warned about the increased risk of aortic dissection, significant hypoglycemia, and mental health adverse effects.[112][113] The European Medicines Agency (EMA) completed a review of serious, disabling, and potentially irreversible adverse effects associated with fluoroquinolones in 2018. These adverse effects included tendonitis, tendon rupture, arthralgia, neuropathies, and other musculoskeletal or nervous system effects.[114]

Treat for a minimum of 5 days. Duration of treatment should be guided by a validated measure of clinical stability (e.g., resolution of vital sign abnormalities, normal cognitive function, ability to eat).[18][116][117] Consider discontinuing treatment when the patient has been afebrile for 48-72 hours and there are no signs of complications (endocarditis, meningitis).[18][116]

Evaluate whether the patient can be switched to oral therapy on a daily basis; the switch should be made as soon as possible. Switch to an oral formulation of the same drug or an oral formulation of a drug within the same drug class.[18]

Consider switching patients to an organism-specific antimicrobial therapy guided by antibiotic sensitivity in patients in whom laboratory tests have revealed a causative organism.

Primary options

ampicillin/sulbactam: 1.5 to 3 g intravenously every 6 hours

More

or

cefotaxime: 1-2 g intravenously every 8 hours

or

ceftriaxone: 1-2 g intravenously every 24 hours

or

ceftaroline fosamil: 600 mg intravenously every 12 hours

-- AND --

azithromycin: 500 mg intravenously every 24 hours

Secondary options

ampicillin/sulbactam: 1.5 to 3 g intravenously every 6 hours

More

or

cefotaxime: 1-2 g intravenously every 8 hours

or

ceftriaxone: 1-2 g intravenously every 24 hours

or

ceftaroline fosamil: 600 mg intravenously every 12 hours

-- AND --

levofloxacin: 750 mg intravenously every 24 hours

or

moxifloxacin: 400 mg intravenously every 24 hours

Consider – MRSA antibiotic cover

Back
ACUTE
|
inpatient
|
in intensive care unit (severe)
Consider – 

MRSA antibiotic cover

Treatment recommended for SOME patients in selected patient group

Additional empiric antibiotic cover is required in patients with risk factors for methicillin-resistant Staphylococcus aureus (MRSA) if locally validated risk factors are present.[18]

Add appropriate additional antibiotic cover and obtain cultures (or nasal polymerase chain reaction if available) to guide de-escalation of therapy or confirm the need to continue therapy.[18]

Consider de-escalation to standard antibiotic therapy at 48 hours provided cultures do not reveal a drug-resistant pathogen and the patient is clinically improving.[18]

A longer treatment course of 7 days is recommended in patients with MRSA.[18]

Primary options

vancomycin: 15 mg/kg intravenously every 12 hours; adjust dose based on serum vancomycin levels

OR

linezolid: 600 mg intravenously every 12 hours

Consider – Pseudomonas antibiotic cover

Back
ACUTE
|
inpatient
|
in intensive care unit (severe)
Consider – 

Pseudomonas antibiotic cover

Treatment recommended for SOME patients in selected patient group

Additional empiric antibiotic cover is required in patients with risk factors for Pseudomonas aeruginosa if locally validated risk factors are present.[18]

Add appropriate additional antibiotic cover and obtain cultures to guide de-escalation of therapy or confirm the need to continue therapy.[18]

Consider de-escalation to standard antibiotic therapy at 48 hours provided cultures do not reveal a drug-resistant pathogen and the patient is clinically improving.[18]

A longer treatment course of 7 days is recommended in patients with P aeruginosa.[18]

Take the initial empiric regimen into account adding Pseudomonas cover so that two antibiotics from the same class are not used together.

Primary options

piperacillin/tazobactam: 4.5 g intravenously every 6 hours

More

OR

cefepime: 2 g intravenously every 8 hours

OR

ceftazidime sodium: 2 g intravenously every 8 hours

OR

imipenem/cilastatin: 500 mg intravenously every 6 hours

More

OR

meropenem: 1 g intravenously every 8 hours

OR

aztreonam: 2 g intravenously every 8 hours

Consider – Enterobacteriaceae antibiotic cover

Back
ACUTE
|
inpatient
|
in intensive care unit (severe)
Consider – 

Enterobacteriaceae antibiotic cover

Treatment recommended for SOME patients in selected patient group

Additional empiric antibiotic cover is required in patients with risk factors for extended-spectrum beta-lactamase-producing Enterobacteriaceae. Consult an infectious disease specialist for guidance on an appropriate antibiotic regimen.[18]

A longer treatment course is recommended in patients in cases of pneumonia due to less common pathogens.[18]

Consider – influenza antiviral cover

Back
ACUTE
|
inpatient
|
in intensive care unit (severe)
Consider – 

influenza antiviral cover

Treatment recommended for SOME patients in selected patient group

Add antiviral treatment (e.g., oseltamivir) to antimicrobial treatment in patients with CAP who test positive for influenza in the inpatient setting, independent of duration of illness before diagnosis.[18]

Primary options

oseltamivir: 75 mg orally twice daily for 5 days

Consider – corticosteroid

Back
ACUTE
|
inpatient
|
in intensive care unit (severe)
Consider – 

corticosteroid

Treatment recommended for SOME patients in selected patient group

The use of corticosteroids in patients with severe CAP has been a long-debated issue.

Current American Thoracic Society (ATS)/Infectious Diseases Society of America (IDSA) guidelines generally recommend against the use of corticosteroids in patients with nonsevere or severe CAP, although acknowledge that they may be considered in patients with refractory septic shock according to Surviving Sepsis Campaign guidelines, and can be used as clinically appropriate for comorbid conditions (e.g., COPD, asthma, autoimmune diseases). This recommendation is based on the fact that there are no data suggesting benefit in patients with nonsevere CAP with respect to mortality or organ failure, and only limited data to support their use in patients with severe CAP.[18]

Plus – supportive care

Back
ACUTE
|
inpatient
|
in intensive care unit (severe)
Plus – 

supportive care

Treatment recommended for ALL patients in selected patient group

Administer oxygen therapy as necessary. Monitor oxygen saturation and inspired oxygen concentration with the aim of maintaining SaO₂ above 92%. High concentrations of oxygen can safely be given in uncomplicated pneumonia. [ Cochrane Clinical Answers logo ] Patients with respiratory failure, despite appropriate oxygen therapy, require urgent airway management and possible intubation. Treatment of patients with COPD complicated by ventilatory failure oxygen therapy should be guided by repeated arterial blood gas measurements.[106]

Assess patients for volume depletion. Administer intravenous fluids if needed according to local protocols, and give nutritional support in prolonged illness.

Monitor temperature, respiratory rate, pulse, blood pressure, and mental status at least twice daily and more frequently in those with severe pneumonia or requiring regular oxygen therapy. Monitor C-reactive protein (CRP) levels regularly as they are a sensitive marker of progress in pneumonia. Repeat chest x-rays in patients who are not progressing satisfactorily. Routine follow-up chest imaging is not recommended if symptoms resolve within 5-7 days.[18]

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Choose a patient group to see our recommendations

Please note that formulations/routes and doses may differ between drug names and brands, drug formularies, or locations. Treatment recommendations are specific to patient groups. See disclaimer

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