Can tobramycin inhalation be improved with a jet nebulizer?

Data on the pharmacokinetics of antibiotics after inhalation are limited. T he aim of this pilot study was to assess the pharmacokinetics of tobramycin under optimalized and standardized aerosol circumstances and, furthermore, to be able to consider possible treatment of exacerbations with inhalation therapy. Six patients were studied after inhalation of 600 mg tobramycin. A jet nebulizer loaded with a 10% solution of tobramycin in water was used. The percentage of the dose that was systemically absorbed ranged from 1.0% to 16.6%. The maximum serum levels of tobramycin ranged from 0.77 mg/L to 3.63 mg/L (mean 1.70 +/- 1.01). The pharmacokinetic data were best describe d by a two-compartment model. Compared to intravenous administration, the l ong terminal half-life (mean 9.47 h +/- 3.28 h) could be explained by the s low absorption of tobramycin from the site of administration (flip-flop mod el). Despite standardized aerosol conditions, considerable interpatient var iability was observed. However, the relatively low serum levels allow a fur ther increase of the dose.