Antibiotics are the mainstay of bacterial pneumonia treatment. Guidelines for the management of community-acquired pneumonia published by the Infectious Diseases Society of America and the American Thoracic Society recommend initiating antibiotic therapy based on disease severity and the individual’s medical history rather than on microbial identification tests (Tedja 2013).
In previously healthy patients, usual first-line therapy includes antibiotics such as amoxicillin-clavulanic acid (Augmentin) or a macrolide antibiotic such as azithromycin, clarithromycin, or erythromycin. In patients with chronic health problems, recent antibiotic use, or other risk factors for drug-resistant bacterial infection, more aggressive treatment is preferred. These regimens are usually effective even when pneumonia is caused by infection with atypical bacteria such as Mycoplasma or Chlamydophila species (Simonetti 2014; Mandell 2007; Musher 2012).
All antibiotics, especially those with broad-spectrum activity, are associated with a range of possible side effects, from mild digestive upset to potentially life-threatening secondary intestinal infections such as Clostridium difficile colitis (Riddle 2009; Dallal 2002; Johanesen 2015).
Several analyses of trial data have found that adjunctive corticosteroids improve outcomes and reduce complication risk in community-acquired pneumonia. These benefits include a shorter length of hospital stay, reduced time to become clinically stable, reduced need for mechanical ventilation, and reduced risk of death in severe cases. These findings have led to recommendations that adjunctive corticosteroids be considered in hospitalized patients with severe community-acquired pneumonia if such treatment is not contraindicated (Siemieniuk 2015; Marti 2015; Horita 2015; Cilloniz 2016; Aoun 2016).
Viral pneumonia is often caused by influenza virus infection, though secondary bacterial pneumonia is a possible complication of viral pneumonia. Antiviral medications, including oseltamivir (Tamiflu) and zanamivir (Relenza), are sometimes used in these cases, though it is not certain that they can effectively treat established influenza virus pneumonia (Musher 2012; Chan 2016). Oseltamivir is associated with side effects including nausea and vomiting (Jefferson 2014).
In cases of severe pneumonia or in patients at high risk of complications, the physician may choose to recommend hospitalization so oxygen, ventilation assistance, and intravenous antibiotics and fluids can be provided (Black 1991; Fine 1990; Mandell 2007; Musher 2012).
Vaccination for Pneumonia Prevention
Vaccines targeting pneumococcal and influenza infections are the cornerstone of medical prevention of community-acquired pneumonia (Mandell 2007). Annual influenza vaccines reduce rates of influenza infections and influenza-associated pneumonia, as well as pneumonia complications and pneumonia hospitalizations (Grijalva 2015; Ridenhour 2013; Simpson 2013; Song 2015). The influenza vaccine is considered especially important for the elderly and other high-risk individuals (Song 2015).
Two pneumococcal vaccines, a 23-valent pneumococcal polysaccharide vaccine (Pneumovax®23) and a 13-valent pneumococcal conjugate vaccine (Prevnar13®) are available and generally recommended for people aged 65 and older and for all high-risk adults (NFID 2014; CDC 2016). The pneumococcal conjugate vaccine, in particular, is effective in eliciting an immune response in people with immune senescence (Kwetkat 2015; van Werkhoven 2015; de Roux 2008). A randomized controlled trial published in 2015, which enrolled nearly 85 000 volunteers aged 65 or older, found that PCV13 was effective in preventing community-acquired pneumonia and invasive pneumococcal disease caused by organisms against which the vaccine is designed to protect (Bonten 2015).
Pneumococcal vaccines also help combat antibiotic resistance, which can help reduce the prevalence of invasive disease caused by difficult-to-treat pneumococcal infections (Lipsitch 2016). Intriguingly, a meta-analysis found that use of the pneumococcal polysaccharide vaccine was associated with a significantly reduced risk of acute coronary syndrome in adults 65 and older (Ren 2015).