Community-Acquired Pneumonia Antibiotics

For an adult with a new infiltrate and compatible acute syndrome, determine outpatient versus inpatient care with a validated severity tool plus clinical judgment. CURB-65 assigns one point each for confusion, urea greater than 7 mmol/L, respiratory rate at least 30/min, systolic blood pressure below 90 mm Hg or diastolic pressure 60 mm Hg or less, and age 65 years or older; PSI is also used to stratify outpatient versus hospital care. ScienceDirect+1ScienceDirectRisk stratification and prediction value of procalcitonin and clinical severity scores for community-acquired pneumonia in ED - ScienceDirectIDSAATS/IDSA Guidelines for Diagnosis and Treatment of Adults with Community-Acquired Pneumonia

Treat suspected CAP empirically for bacterial infection or bacterial coinfection at presentation because no rapid diagnostic test can reliably establish that CAP is exclusively viral at that point. COVID-19 pneumonia may be an exception. PubMedPubMedOptimizing Diagnosis and Management of Community Acquired Pneumonia in the Emergency Department - PMC

Separate severe CAP from nonsevere inpatient CAP before selecting therapy. Severe CAP is present with one major criterion or at least three minor criteria under ATS/IDSA criteria; severe disease drives ICU-level assessment, broader microbiologic testing, and selection of a combination regimen rather than routine fluoroquinolone monotherapy. PubMed+1PubMedAspiration Pneumonia - StatPearls - NCBI Bookshelf - NIHIDSAATS/IDSA Guidelines for Diagnosis and Treatment of Adults with Community-Acquired Pneumonia

For outpatient adults without comorbidities or resistant-pathogen risk factors, amoxicillin or doxycycline are the principal empiric options described for coverage centered on Streptococcus pneumoniae. Doxycycline also covers atypical organisms and may cover Haemophilus influenzae and Staphylococcus aureus. PubMedPubMedOptimizing Diagnosis and Management of Community Acquired Pneumonia in the Emergency Department - PMC

Macrolide monotherapy requires caution because empiric atypical coverage remains debated and resistance can undermine macrolide-only treatment. If a macrolide is selected, anchor the decision to local pneumococcal susceptibility data and patient-specific arrhythmia and drug-interaction risk. BMJ+1BMJCommunity-acquired pneumonia in adults - BMJ Best PracticeIDSAATS/IDSA Guidelines for Diagnosis and Treatment of Adults with Community-Acquired Pneumonia

For outpatients with chronic heart, liver, renal, or lung disease; diabetes; alcoholism; asplenia; or malignancy, select a broader regimen consistent with CAP guidance because comorbidity is associated with vulnerability to inadequate empiric therapy and may coexist with risk factors for resistant organisms. BMJ+1BMJCommunity-acquired pneumonia in adults - BMJ Best PracticePubMedAspiration Pneumonia - StatPearls - NCBI Bookshelf - NIH

For hospitalized adults with nonsevere CAP and no risk factors for MRSA or Pseudomonas aeruginosa, guideline-concordant empiric options are a beta-lactam plus macrolide or respiratory fluoroquinolone monotherapy. ScienceDirect+1ScienceDirectComparison of Empiric Antibiotic Treatment Regimens for Hospitalized, Non-severe Community-acquired Pneumonia: A Retrospective, Multicenter Cohort Study - ScienceDirectIDSAATS/IDSA Guidelines for Diagnosis and Treatment of Adults with Community-Acquired Pneumonia The selection between these options should account for allergy history, prior antibiotic exposure, adverse-effect risk, local susceptibility patterns, and the ability to transition to oral treatment.

Use a beta-lactam-based combination regimen for severe CAP rather than default respiratory fluoroquinolone monotherapy. Severe CAP also warrants intensified diagnostic sampling because a microbiologic diagnosis can permit pathogen-directed de-escalation and identify pathogens requiring a longer course. BMJ+2BMJCommunity-acquired pneumonia in adults - Diagnosis recommendations | BMJ Best Practice USIDSAATS/IDSA Guidelines for Diagnosis and Treatment of Adults with Community-Acquired PneumoniaPubMedAspiration Pneumonia - StatPearls - NCBI Bookshelf - NIH

A prior respiratory isolation of MRSA or Pseudomonas aeruginosa is the strongest practical signal to consider empiric pathogen-directed coverage. Recent hospitalization with administration of parenteral antibiotics during the prior 90 days is another key risk factor; local epidemiology should modify this decision. BMJ+2BMJCommunity-acquired pneumonia in adults - BMJ Best PracticeBMJCommunity-acquired pneumonia in adults - Diagnosis recommendations | BMJ Best Practice USIDSAATS/IDSA Guidelines for Diagnosis and Treatment of Adults with Community-Acquired Pneumonia

Use rapid molecular influenza testing rather than antigen-based assays when influenza is circulating in the community; testing can also be considered during low influenza activity. BMJ+1BMJCommunity-acquired pneumonia in adults - Diagnosis recommendations | BMJ Best Practice USIDSAATS/IDSA Guidelines for Diagnosis and Treatment of Adults with Community-Acquired Pneumonia In hospitalized patients, consider nucleic acid testing for noninfluenza respiratory viruses when CAP is severe or the patient is immunocompromised. BMJBMJCommunity-acquired pneumonia in adults - Diagnosis recommendations | BMJ Best Practice US

Send sputum or lower-respiratory cultures and blood cultures for severe CAP, empiric MRSA treatment, empiric Pseudomonas treatment, or prior respiratory infection with either organism. BMJ+1BMJCommunity-acquired pneumonia in adults - Diagnosis recommendations | BMJ Best Practice USIDSAATS/IDSA Guidelines for Diagnosis and Treatment of Adults with Community-Acquired Pneumonia These indications focus testing where an identified pathogen can directly contract or redirect an initially broad regimen.

Do not use procalcitonin as a stand-alone rule-out test for bacterial CAP or as the sole determinant of hospital disposition. Procalcitonin correlates with CAP severity in observational data, but biomarkers have not been sufficiently evaluated to determine hospitalization decisions. ScienceDirect+1ScienceDirectProcalcitonin and severity of community-acquired pneumonia - ScienceDirectScienceDirectRisk Prediction With Procalcitonin and Clinical Rules in Community-Acquired Pneumonia - ScienceDirect

For low-, moderate-, or high-severity uncomplicated CAP, treat for a minimum of 5 days, including when clinical stability is reached earlier. PubMedPubMedDuration of Antimicrobial Treatment in Adult Patients with Pneumonia: A Narrative Review A duration-effect meta-analysis included randomized comparisons of the same agent at the same daily dose across different durations in adult outpatients and non-ICU inpatients, supporting the clinical focus on avoiding unnecessarily prolonged treatment in uncomplicated disease. PubMedPubMedOptimal duration of antibiotic treatment for community-acquired pneumonia in adults: a systematic review and duration-effect meta-analysis - PMC

Use 7 days of therapy for proven or suspected MRSA or Pseudomonas aeruginosa CAP. PubMedPubMedDuration of Antimicrobial Treatment in Adult Patients with Pneumonia: A Narrative Review Extend or individualize treatment when there is an infectious complication such as empyema or lung abscess, persistent instability, or a pathogen-directed indication not represented by uncomplicated CAP duration evidence. BMJ+1BMJCommunity-acquired pneumonia - Management recommendations | BMJ Best PracticePubMedDuration of Antimicrobial Treatment in Adult Patients with Pneumonia: A Narrative Review

At discharge, confirm that oral absorption is reliable and that the selected oral agent retains activity against any recovered pathogen. Persistent fever or dyspnea alone should trigger a focused evaluation for treatment failure or complications rather than automatic broadening or prolonged antibiotics. BMJ+1BMJCommunity-acquired pneumonia - Management recommendations | BMJ Best PracticeBMJAdapting global guidelines to local contexts: optimising community ...