TREATMENT FOR SUPERIMPOSED PSEUDOMONAS AERUGINOSA INFECTION

Pseudomonas aeruginosa These bacteria show resistance to antibiotics A combination of two or more antibiotics is used to destroy the bacteria Antibiotic Selection takes into account local patterns of antimicrobial susceptibility

Combination therapy in most severe infections due to P. Aeruginosa, two antipseudomonal antibiotics to which the strain is sensitive should be administered together Benefits of this combined therapy: 1.Increased efficacy (more efficacious than monotherapy) 2.Achievement of additive or synergistic killing 3.Prevention of antibiotic resistance emergence Fauci et al. Harrison’s Principles of Internal Medicine

Antimicrobial agents active against Pseudomonas aeruginosa 1.aminoglycosides (gentamicin, amikacin, tobramycin) 2.quinolones (ciprofloxacin, levofloxacin, and moxifloxacin) 3.cephalosporins (ceftazidime, cefepime, cefoperazone, cefpirome, but not cefuroxime, ceftriaxone, cefotaxime) 4.ureidopenicillins and carboxypenicillins (piperacillin, ticarcillin: P. aeruginosa is intrinsically resistant to all other penicillins) 5.carbapenems (meropenem, imipenem, doripenem, but not ertapenem) 6.polymyxins (polymyxin B and colistin) 7.monobactams (aztreonam) Fauci et al. Harrison’s Principles of Internal Medicine

Duration of Antibiotic therapy depends on: 1.Type 2.Location 3.Severity of infection * In general: therapy lasts for weeks or even months rather than days Fauci et al. Harrison’s Principles of Internal Medicine

Antibiotic Resistance in P. aeruginosa is both: Intrinsic - as reflected by the relative paucity of antibiotics with inherent activity against wild type strains Acquired - as defined by high level resistance to agents that normally would be expected to exhibit antimicrobial activity Fauci et al. Harrison’s Principles of Internal Medicine

Increase in Antibiotic resistance Inadequate infection control procedures Increased severity of illness in hospitalized patients Expanding use of immunosuppressive therapies Growing antibiotic use Fauci et al. Harrison’s Principles of Internal Medicine

Therapy for RESISTANT P. aeruginosa infections Antimicrobial agents selected on basis of extended susceptibility testing Increased treatment duration Surgical drainage and removal of infected tissues Fauci et al. Harrison’s Principles of Internal Medicine