Ertapanem therapy for community-acquired pneumonia in the elderly.

Abstract

To the Editor: We read with great interest the paper of Woods et al. on ertapenem therapy for community-acquired pneumonia (CAP) in the elderly.1 We agree with the fact that the spectrum of activity of ertapenem includes the most common and the most important bacterial causes of CAP in the elderly. However, in our opinion, there are two restrictions on the results of this study. First, the ecological consequences of widespread use of this broad-spectrum antibiotic could lead to the development of many resistant microorganisms (e.g., Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus) for which the choice of an appropriate second-line antibiotic therapy could be difficult, even with a bacteriological culture of respiratory secretions. Second, the authors reported in their study a mortality rate of 4.2% in the ertapenem group and 4.9% in the ceftriaxone group during total study therapy. Although it is not specified whether these deaths are due to a failure of the treatment or to other complications or whether these deaths occurred early in the management of the CAP, this mortality rate is surprisingly low in the treatment of CAP in elderly patients. Indeed, in most publications regarding prognosis of CAP in the elderly, mortality rates vary between 8% and greater than 20% in patients that do not require mechanical ventilation. (In an intensive care unit, the reported mortality rate of CAP in elderly patients varies between 17%2 and 40%.3) In a prospective study of 101 elderly patients with CAP (aged 78.5±7.9) Riquelme et al. found a crude mortality rate of 26% and a pneumonia-related mortality of 20%.4 In a large retrospective study including 14,069 patients aged 65 and older hospitalized with pneumonia, Meehan et al. found a mortality rate that increased with the risk-category group (calculated according to the methods of Fine et al.5) from 4.3% in Group III to 13.3% in Group IV and 34.4% in Group V, with a total mortality rate of 15.3% at Day 30.6 According to these results, the expected mortality rate in the study of Woods et al. should be 10% in the ertapenem group and 10.1% in the ceftriaxone group. According to the lowest mortality rate derived from the study of Fine et al., these mortality rates should be 6% in the ertapenem group and 6.1% in the ceftriaxone group. Thus, in the study of Woods et al., there is an undermortality rate of at least 30% in the ertapenem group and 20% in the ceftriaxone group compared with the best expected values of mortality rate in these elderly patients treated for CAP. It would be beneficial if the authors could explain these particular therapeutic differences so that all the physicians interested in the treatment of CAP in the elderly could use these findings in their practice.