Intrathecal baclofen does not inhibit the growth of different bacterial species and Candida albicans

BackgroundThe antimicrobial activity of intrathecal baclofen was investigated. Several different microorganisms were used: Staphylococcus aureus (β-lactamase–positive and β-lactamase–negative strains); S epidermidis; Enterococcus faecalis; Klebsiella pneumoniae; Escherichia coli; Pseudomonas aeruginosa; and Candida albicans.MethodsThree experimental approaches were used to assess baclofen antimicrobial activity: (1) determination of the MIC; (2) determination of the MBC; and (3) kinetic time-kill assay. Experiments were performed according to current methods of the NCCLS.ResultsAs compared with control organisms exposed to physiologic saline, organisms exposed to baclofen over a 10-day period failed to reduce the number of viable cells by at least 3 log10, as requested by NCCLS criteria.ConclusionsBecause the viability of the investigated organisms was not reduced over that of microbial suspensions exposed to physiologic saline, we conclude that intrathecal baclofen has no measurable activity against different bacterial species and C albicans.