Community acquired pneumonia (CAP), being one of the common infectious diseases is a major cause of mortality worldwide.

The burden of CAP has been worsened by HIV epidemic in South Asian and African settings. The influx and outflux of various antibiotics had posed a major threat to the rapid increase in antibiotic resistance. An approach to standardize care by providing the evidence-based management strategies would help lower the risk of antimicrobial resistance. The focus of different organizations for the management of CAP has helped to frame certain guidelines.

Two of the most esteemed societies; Infectious Diseases Society of America (IDSA) and the American Thoracic Society (ATS) have established a joint committee to develop a CAP guidelines document. The guidelines are intended primarily for use by emergency medicine physicians, hospitalists, and primary care practitioners; as well as a starting point for consultation by the specialists.

General recommendations on antibiotic use for CAP

• The recommendations made are for a class of antibiotics and not for a specific drug.
• Combination empirical therapy for severe CAP has been recommended as it has been strengthened by a number of evidences.
• Ertapenem, a β-Lactam type antibiotic has been added to the recommendations. It can be used for hospitalized patients with the risk of infection with gram-negative bacteria other than Pseudomonas aeruginosa.
• Telithromycin drug is being evaluated for its safety by the US Food and Drug Administration before its final recommendation.
• More potent drugs are used as they help in mitigating the risk of selection for antibiotic resistance.

For outpatient treatment

• For a healthy person with no risk factors for drug-resistant S. pneumoniae infection, macrolides (azithromycin, clarithromycin, or erythromycin) are highly recommended. Doxycycline is weakly recommended.
• In regions with high rate of infection and macrolide-resistant S. pneumonia and for people suffering with conditions pertaining to heart, lung, liver, or renal disease; diabetes mellitus; alcoholism; malignancies; asplenia; immunosuppressing conditions or use of immunosuppressing drugs; use of antimicrobials within the previous 3 months (in which case an alternative from a different class should be selected); or other risks for drug-resistant S.pneumoniae infection then, the following antibiotic classes can be given:
• A respiratory fluoroquinolone (moxifloxacin, gemifloxacin, or levofloxacin [750 mg])
• A β-lactam plus a macrolide (High-dose amoxicillin or amoxicillin-clavulanate is preferred and the alternatives include ceftriaxone, cefpodoxime, and cefuroxime)

For ICU inpatients

For ICU inpatients, a β-lactam (cefotaxime, ceftriaxone, or ampicillin-sulbactam) plus either azithromycin or a fluoroquinolone is recommended. For patients who are allergic to penicillin, a respiratory fluoroquinolone and aztreonam are recommended.

Antipneumococcal, antipseudomonal β-lactam (piperacillin-tazobactam, cefepime, imipenem, or meropenem) plus either ciprofloxacin or levofloxacin are recommended for pseudomonas infection.

For community-acquired methicillin-resistant Staphylococcus aureus (MRSA) infection, vancomycin or linezolid are recommended.

For emergency admissions

For patients admitted through the emergency department, the first antibiotic dose should be administered while in the emergency department itself, rather than designating a specific window period for the dosage administration.

Pathogen directed therapy

Antimicrobial therapy should be directed at the pathogen that has been identified on the basis of reliable microbiological methods for CAP etiology.

Oseltamivir or zanamivir as early treatment i.e within 48 hours of the onset of symptoms is recommended for influenza.

For patients with uncomplicated influenza (with symptoms for 148 h), use of oseltamivir and zanamivir is not recommended. But, these drugs may be used to reduce viral shedding in hospitalized patients or for patients with influenza pneumonia.

Duration of antibiotic therapy

Adults with CAP should be treated for a minimum of 5 days. Before discontinuation of therapy, ensure that the patient has normal body temperature for 48–72 hours, and should have not more than one CAP-associated sign of clinical instability.

Duration of therapy may be extended if initial therapy was not active against the identified pathogen or if it was complicated by extrapulmonary infection, such as meningitis or endocarditis.