[Evolution of use of antibiotics of restricted prescription and trend of bacterial susceptibility in Concepcion Regional Hospital, Chile].

The aim of this study was analyze the use of restricted antibiotics by patients hospitalized between 2004 and 2008 in Guillermo Grant Benavente Hospital in Concepcion. Also we attempted to identify possible correlations between antibiotic consumption and patterns of bacterial susceptibility. We performed a retrospective observational study that quantified the use of restricted antibiotics using DDD/100-bed-days, and cumulative susceptibility reports informed by the hospital's microbiology laboratory for bacterial susceptibility. The consumption of restricted antibiotics significantly increased between 2004 and 2008 (35%, p = 0.005). The groups with largest use were glycopeptides (37%) and carbapenems (30 %). These results can be explained by the emergence of endemic Methicillin-resistant Staphylococcus aureus (MRSA) and of Extended-spectrum beta-lactamase (ESBL) Gram negative bacilli. Results showed a decrease in susceptibility of P. aeruginosa to imipenem (p = 0.038) and K. pneumoniae to ciprofloxacin (p = 0.021). The total consumption of restricted antibiotic has significantly increased, especially among complex medical services. A significant decrease in bacterial susceptibility has been observed mainly in gram-negative bacilli. The monitoring of antimicrobial prescribing practices and local susceptibility patterns are essential to promote the rational use of antibiotics.