Antibiotics fail in 1 out of 4 pneumonia cases
Almost one in four adults treated with an antibiotic for community-acquired pneumonia (CAP) fails to respond to treatment, a study presented at the ATS Conference 2017 has shown.
Treatment failure─defined as either the need for additional antibiotic therapy (refill), antibiotic switch, hospitalization, or emergency department visit within 30 days of initial antibiotic prescription─occurred in 22.1 percent (n=55,741) of the patients studied. [ATS 2017, abstract 8450]
The high rate of treatment failure “is concerning”, said lead author Dr James McKinnell from the Los Angeles Biomedical Research Institute in Los Angeles, California, US, noting that “pneumonia is the leading cause of death from infectious diseases in the US.”
The retrospective cohort involved 251,947 adult outpatients (mean age, 52.2 years, 47.7 percent) from healthcare databases, who were prescribed with antibiotic monotherapy from one of the four drug classes: macrolides, beta-lactams, fluoroquinolones, or tetracyclines, following a clinical consultation for CAP.
Individuals who failed antibiotic treatment tended to be older (p<0.0001), female (p<0.0001), and have pneumococcal pneumonia (p<0.02) than those who were responsive to treatment.
Presence of comorbidities, including hemiplegia/paraplegia (odds ratio [OR], 1.33), rheumatologic disease (OR, 1.28), chronic pulmonary disease (OR, 1.25), cancer (OR, 1.14), diabetes (OR, 1.07), and asthma (OR, 1.05), was similarly associated with an increased risk of antibiotic failure.
Also, the higher the Charlson Comorbidity Index (CCI) score, the greater the likelihood of failing an antibiotic treatment: the odds of failure were 1.16 for CCI=1, 1.22 for CCI=2, and 1.44 for CCI≥3 compared with CCI=0.
After adjusting for the various risk factors, the highest antibiotic failure rate was seen with beta-lactams (25.7 percent), followed by macrolides (22.9 percent), tetracyclines (22.5 percent), and fluoroquinolones (20.8 percent).
“Prescribers should be aware of those CAP patients at risk for poor outcomes and consider these factors to guide a comprehensive treatment plan, including more appropriate antibiotic treatment,” advised McKinnell.
“Perhaps the most striking example is the association between age and hospitalization: Patients over the age of 65 were nearly twice as likely to be hospitalized compared to younger patients when our analysis was risk adjusted … Elderly patients are more vulnerable and should be treated more carefully, potentially with more aggressive antibiotic therapy,” he said.
McKinnell also suggested that current CAP treatment guidelines should be updated to better define risk factors for treatment failure and optimize the choice of antibiotics.
“The additional antibiotic therapy noted in the study increases the risk of antibiotic resistance and complications like C. difficile infection, which is difficult to treat and may be life-threatening, especially for older adults,” he added.