Los Angeles—About one-fourth of the antibiotics pharmacists fill for patients with pneumonia end up not curing the respiratory infection, new research has found.

The study presented at the 2017 American Thoracic Society International Conference sought to add real-world data to community-acquired pneumonia treatment guidelines published in 2007 by the American Thoracic Society and the Infectious Disease Society of America.

“Pneumonia is the leading cause of death from infectious disease in the United States, so it is concerning that we found nearly one in four patients with community-acquired pneumonia required additional antibiotic therapy, subsequent hospitalization or emergency room evaluation,” explained lead author James A. McKinnell, MD, an LA BioMed lead researcher and infectious-disease specialist. “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.”

To reach those conclusions, the study team employed databases containing records for 251,947 adult patients who were treated between 2011 and 2015 with a single class of antibiotics—beta-lactam, macrolide, tetracycline, or fluoroquinolone—for community-acquired pneumonia after a medical office visit.

Treatment failure was defined as the need to refill antibiotic prescriptions or switch antibiotics, a visit to an emergency department, or hospital admission within 30 days of getting the initial antibiotic prescription.

Results indicate an antibiotic failure rate of 22.1%. It was even higher for older patients or those with comorbidities, study authors emphasize.

After adjustment for patient characteristics, the failure rates by class of antibiotic were:
• Beta-lactams, 25.7%
• Macrolides, 22.9%
• Tetracyclines, 22.5% and
• Fluoroquinolones, 20.8%

“Our findings suggest that the community-acquired pneumonia treatment guidelines should be updated with more robust data on risk factors for clinical failure,” McKinnell noted. “Our data provide numerous insights into characteristics of patients who are at higher risk of complications and clinical failure. 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 and nearly three times more likely in unadjusted analysis. Elderly patients are more vulnerable and should be treated more carefully, potentially with more aggressive antibiotic therapy.”

Also found in the study were regional variations in treatment outcomes, which are not addressed in community-acquired pneumonia guidelines. Also, study authors determined that certain patients with comorbid conditions, including chronic obstructive pulmonary disease, cancer, and diabetes, were not treated with combination antibiotic therapy or respiratory fluoroquinolone, as recommended in the guidelines.

“While certain aspects of the guidelines need to be updated, some prescribers also have room for improvement and should implement the current guidelines,” McKinnell said.

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