Unexpected antimicrobial effect of statins.

OBJECTIVES Epidemiological studies of statins have suggested a link between statin therapy and a decreased risk of sepsis. It has been proposed that the mechanism underlying this apparent protective effect of statins relates to their known immunomodulatory and anti-inflammatory effects. The aim of this study was to explore the antimicrobial effect of statins. METHODS Simvastatin (Merck) and fluvastatin (Novartis) were both tested against six of each of methicillin-susceptible and -resistant Staphylococcus aureus (MSSA + MRSA), and vancomycin-sensitive and -resistant enterococci (VSE + VRE) using a microtitre dilution method. The test was repeated five times for both statins against all 24 isolates. Vancomycin, linezolid and propranolol were used as controls, as appropriate. RESULTS AND DISCUSSION Simvastatin showed a significant antimicrobial effect against MSSA (mean MIC 29.2 mg/L) and to a lesser extent against MRSA (mean MIC 74.9 mg/L). Fluvastatin had a significantly less marked antimicrobial effect. Propranolol showed no antimicrobial effect. Simvastatin has a considerable antimicrobial effect in vitro and further testing of it is warranted.