Guidelines recommend use of a respiratory fluoroquinolone antibiotic or combination antibiotic therapy for outpatient treatment of community-acquired pneumonia (CAP) if patients have risk factors for drug-resistant Streptococcus pneumoniae (DRSP). Despite these guidelines, most CAP patients are treated the same, reveals a new study. Because S. pneumoniae had developed immunity to some important antimicrobial drugs, two professional societies published a consensus guideline in 2007 on the management of CAP. These guidelines took into account risk factors (for example, recent antibiotic use and chronic medical conditions) in recommending specific antibiotic regimens.
The researchers retrospectively studied 175 adult outpatients treated for CAP in the emergency department or urgent care center of an urban, academic medical center during a 6-month period in 2009. They looked at antibiotic use in patients with and without DRSP risk factors. One or more DRSP risk factors were found in 51 percent of cases, including asthma (16 percent of cases), alcohol abuse (14 percent), diabetes (10 percent), and three other factors (9 percent of the cases each).
At the initial visit, antibiotic prescriptions were similar among patients with and without DRSP risk factors: a macrolide in 62 percent versus 59 percent, doxycycline in 27 percent versus 28 percent, or a respiratory fluoroquinolone in 9 percent of both groups. Patients with DRSP risk factors were treated according to the guideline recommendations far less frequently than cases without risk factors (9 percent vs. 87 percent).
The researchers noted, however, that strict adherence to the guidelines would have resulted in greater use of fluoroquinolones or combination antimicrobial therapy, which could increase the risk of drug resistance in other microorganisms. The study was funded in part by AHRQ (HS17526).
More details are in "Risk factors for drug-resistant Streptococcus pneumoniae and antibiotic prescribing practices in outpatient community-acquired pneumonia," by Timothy C. Jenkins, M.D., Joy Sakai, M.D., Bryan C. Knepper, M.P.H., M.Sc., and others in Academic Emergency Medicine 19(6), pp. 703–706, 2012.