Hospital acquired gram-negative pneumonias: response rate and dosage requirements with individualized tobramycin therapy.

Individualized tobramycin therapy was systemically evaluated in 26 patients with gram-negative pneumonias involving Pseudomonas aeruginosa and other multiple antibiotic-resistant pathogens. Patient prognoses were classified by underlying diseases, and response was determined according to previously established criteria. Twenty-three patients (88%), including all 11 cases involving multiple antibiotic-resistant pathogens and 12 of 15 cases involving Pseudomonas aeruginosa, successfully responded to individualized tobramycin therapy. Tobramycin daily dosages and pharmacokinetic parameters demonstrated a wide interpatient variability. Measured peak and trough serum concentrations resulting from individualized dosage regimens closely matched desired peak and trough concentrations. Clinical ototoxicity or nephrotoxicity were not observed. Individualizing dosage regimens was an important factor in obtaining therapeutic serum concentrations that may influence treatment response to tobramycin therapy.