Treatment options for community-acquired pneumonia in the elderly people

Abstract

Community-acquired pneumonia (CAP) represents one of the most common reasons for hospitalization in elderly people. Because older persons are the fastest growing segment of the population, a further increase of the incidence of CAP is expected in the next few years. Due to the high frequency, the different epidemiology, the atypical clinical presentation and the age-related modifications in drug metabolism that complicate the treatment, infections in the elderly people represent a major challenge for physicians. Despite the peculiarity of the management of CAP in the elderly people, no specific recommendations for antimicrobial treatment are provided in the international guidelines. The aim of this review is to give an update of the current antibiotic options for CAP in the elderly people reporting available data on the CAP etiology and risk factors, and tolerability, toxicity and pharmacokinetics/pharmacodynamic of antimicrobial agents used for elderly patients.

Keywords:

• aged persons
• antibiotic agents
• antibiotic-resistance
• bacterial pneumonia
• pharmacokinetics and pharmacodynamic characteristics

Acknowledgements

N Petrosillo and MA Cataldo are active members of the European Society of Clinical Microbiology and Infectious Diseases (ESCMID)–Study Group for Infections in the Elderly (ESGIE) and would like to thank the ESGIE members for their stimulating support to write this review.

Financial & competing interests disclosure

N Petrosillo received honoraria as speaker for Pfizer, Astellas, Merk Sharp & Dohme, Novartis, Gilead, Carefusion, Johnson & Johnson, The Medicines Company, Achaogen. MA Cataldo had recent national advisory board with Basilea Pharmaceutica. F Pea has accepted speaking and conference invitations from Astra Zeneca, Gilead, Merck Sharp & Dohme, Novartis, Pfizer and Sanofi Aventis, and has had recent or ongoing scientific advisory boards with Astra Zeneca, Boehringer Ingelheim and Pfizer. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.

Key issues

• The aging process is accompanied by several physiologic changes including declines in maximal oxygen uptake capacity and cardiovascular function, decreased elasticity of the lungs and skin, decreased renal function, decreased muscle mass, decrease in the cellular and humoral immunity.

• Community-acquired pneumonia (CAP) represents one of the most common reasons for hospitalization in elderly people being the third commonest hospital diagnosis among patients aged ≥65 years. The reported incidence of pneumonia is 8.4 cases per 1000 inhabitants among individuals with 65 years and more, and its incidence is sixfold higher among very old individuals (over 90 years of age).

• The majority of CAP in the elderly is due to Streptococcus pneumoniae, followed by Hemophilus influenzae. Ranges of Legionella pneumophila CAP vary from 1 to 9%. Staphylococcus aureus occurs in fewer than 7% of cases of CAP. The most relevant risk factor for S. aureus pneumonia in the elderly people is represented by the frequent colonization by S. aureus in patients who have had a previous episode of influenza.

• According to the IDSA/ATS guidelines, in previously healthy patients who have not used antimicrobials within the previous 3 months, recommended treatment options comprise macrolides or tetracyclines as monotherapy or part of combination therapy (e.g., with β-lactam antibiotics) in patients with comorbidities. However, patients treated with macrolides may be at higher risk of developing Clostridium difficile infection. Given these premises, the risk–benefit analysis for treating CAP may favor doxycycline, especially in patients greater than 65 years who would be receiving outpatient treatment.

• Fluoroquinolones are among the guidelines recommended agents for CAP. In the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) guidelines, experts state that within the fluoroquinolones, moxifloxacin has the highest antipneumococcal activity. Moxifloxacin in the elderly population has a similar profile as regards cardiac rhythm safety as compared with levofloxacin.

• Elderly people have typical risk factors associated with antibiotic resistance including: frequent contact with the health system (prior hospitalizations, residency in long-term facilities or nursing homes, home healthcare programs, home intravenous therapy and wound care, hemodialysis), frequent antibiotic exposure, incontinence, frailty. For these patients, treatment should be tailored according to the risk factors for the presence of multidrug-resistant organisms.

• Antimicrobial therapy in older individuals is influenced by more than just physiologic changes. Comorbidities and immunosenescence, the deregulated immune function associated with aging, predisposes elderly persons to suboptimal therapeutic efficacy, and therefore pharmacokinetics considerations should be carefully done for older individuals when administering them antimicrobials.

Notes

ICU: Intensive care unit.

CA-MRSA: Community-associated methicillin-resistant Staphylococcus aureus; ICU: Intensive care unit.

Of note, therapy with nonrenally cleared antimicrobials must always be started full loading dose and then continued with full maintenance dosages, regardless of patient’s renal function.