Antibiotic consumption and susceptibility of isolates in patients with low respiratory tract infection
Objectives: Determining whether variations in time of use of quinolones: Levofloxacin (LVF), and betalactamics (BTL): Penicillin (P), Amoxicillin-Clavulanate (AMC), Imipenem (IMP) and Ceftriaxone (CFT); have been parallel to variations in the sensitivity of the main respiratory pathogens.
Material and methods: We studied a total of 470 strains during the period 2006 – 2013 from patients treated in our Health Area, diagnosed with respiratory infection being mostly sputum, bronchial aspirates, and biological fluids (pleural and bronchoalveolar lavage). The gender distribution was 62% male and 38% female. The bacterial resistance was determined by study of the Minimum Inhibitory concentration (MIC) (E-test diffusion agar), following the recommendations of the Clinical and Laboratory Standars Institute (CLSI) 2013 (Document-M02-A11). The use of antibiotics in hospitalized patients was obtained through the Hospital Pharmacy Service, using as technical unit of measure the Defined Daily Dose (DDDs) per 100 beds/day.
BTL consumption showed a decline from 2011. However, in the CFT we observed an increase from the year 2008. Regarding LVF, it remained constant.
Most isolates of S. pneumoniae were sensitive, without finding changes for betalactamics, except with AMC (in 2013). With H. influenzae were not variations, being sensitive to the two groups of antibiotics (94.58% and 93.78%). Regarding Pseudomonas spp. was a decline in the number of sensitive isolates from 2009. Prevalence for LVF remains, being more sensitive to them than againts betalactamics. M. catarrhalis showed no significant changes in sensitivity.
In our study, the observed decline in the consumption of BTL from the year 2011 was not accompanied by a parallel increase in consumption of levofloxacin.
conclusions: Betalactamics consumption in our hospital for the treatment of respiratory infections remains higher than levofloxacin. However, percentage of isolates sensitive to that antibiotic comes to be superior in some of the microorganisms tested. That is why levofloxacin is an effective alternative to betalactamics in the treatment of low respiratory tract infections.