Broad-spectrum antibiotics dispensed to almost half of healthy adult outpatients with CAP
An analysis of oral antibiotic regimens dispensed to healthy outpatients with community-acquired pneumonia (CAP) in 2007 through 2019 found that 48% got broad-spectrum drugs and that they had significantly higher rates of adverse drug events than patients who got macrolide monotherapy.
Broad-spectrum antibiotics were associated with increased risk of adverse drug events (ADEs) among otherwise healthy outpatient adults treated for community-acquired pneumonia (CAP), a study found.
Researchers conducted an active comparator new-user cohort study of commercially insured adults ages 18 to 64 years diagnosed with outpatient CAP, evaluated by chest X-ray, and dispensed a same-day oral antibiotic regimen in 2007 through 2019. Follow-up for ADEs ranged from two to 90 days. Ankle/knee sprain and influenza vaccination were used as negative control outcomes. Results were published by Clinical Infectious Diseases on Oct. 23.
Among the 145,137 otherwise healthy CAP patients without comorbidities, slightly more than half (52%) received narrow-spectrum antibiotics, mostly consisting of macrolides (n=63,474; 44%), followed by doxycycline (n=11,301; 8%). Broad-spectrum regimens were prescribed to 48%, mostly fluoroquinolones (n=56,388; 39%), followed by beta-lactam monotherapy (n=9,652; 7%), a beta-lactam plus a macrolide (n=4,322; 3%), or, rarely, a beta-lactam plus doxycycline (n=612).
Compared to macrolide monotherapy, broad-spectrum antibiotic regimens were associated with increased risk for several ADEs. For example, beta-lactams increased nausea, vomiting, or abdominal pain (risk difference [RD] per 100 treatment episodes, 0.32 [95% CI, 0.10 to 0.57]), non-Clostridioides difficile diarrhea (RD per 100, 0.46 [95% CI, 0.25 to 0.68]), and vulvovaginal candidiasis/vaginitis (RD per 100, 0.36 [95% CI, 0.09 to 0.69]). Risks among narrow-spectrum antibiotic regimens were largely similar, and there were generally similar risks of the negative control outcome, indicating minimal confounding.
The study authors wrote that antimicrobial stewardship is needed to promote judicious use of broad-spectrum antibiotics and ultimately decrease antibiotic-related ADEs, adding that future research on the safety of amoxicillin monotherapy is warranted.
“Results of the present study add to accumulating evidence suggesting that efforts to shift prescribing from broader-spectrum antibiotics to narrower-spectrum antibiotics may prevent ADEs,” they wrote. They noted that unlike the 2007 guidelines from the American Thoracic Society and Infectious Diseases Society of America, the updated 2019 guidelines strongly recommend routine use of doxycycline, based on limited data mostly involving small numbers of patients. “Our findings of similar risk of ADEs compared to macrolide monotherapy support the safety of doxycycline for treatment of outpatient CAP,” the authors wrote.