Controversies in antimicrobial therapy: innovative methods of administration

The clinical use of novel means of antibiotic administration--continuous infusion, endotracheal instillation and aerosol delivery, peritoneal dialysate, and antibiotic-impregnated catheters, bone cement, and beads--is discussed. Antibiotic infusions have traditionally been administered intermittently, but recent data support the use of continuous infusions in treating gram-negative bacillus bacteremias in neutropenic patients. Local instillation of antibiotics--endotracheally or by aerosols--may be indicated in patients with pulmonary infections and damaged pulmonary-defense systems; in other patients, normal host defenses make local therapy unnecessary. Patients undergoing chronic ambulatory peritoneal dialysis often develop intraperitoneal staphylococcal and streptococcal infections, and these are best treated with antibiotics added directly to the dialysate. Other recent studies support the use of antimicrobial agents in medical devices. Antibiotic-impregnated catheters are being tested as means of preventing difficult-to-treat catheter-related infections. Bone cement containing aminoglycosides has proven useful in preventing deep-bone infections in patients undergoing total-hip arthroplasty, and antibiotic-impregnated beads are useful, along with debridement, in patients with osteomyelitis. Innovative and unique methods of antibiotic administration are useful in overcoming problems of drug toxicity and failure of agents to reach sites of infection.