Anti-infectious aerosols.

Anti-infectious agents such as pentamidine, antibiotics (mainly colistine a nd aminoglycosides) and amphotericin B can be administered by aerosol. This route of administration is nor officially approved and it constitutes an e mpirical approach which has benefited from recent research which is summari zed hereafter. The most fundamental question is related to the potentially deleterious effects of nebulization processes, especially ultrasound on the anti infectious properties of the drugs. Colimycin, which was chosen as a reference because ifs poly peptide structure makes it unstable a priori, pr oved to be resistant to high frequency ultrasound, which is encouraging for other molecules such as aminoglycosides or betalactamins. The nebulizer ch aracteristics have also to be taken into account. An aerosol can be produce d from an amphotericin B suspension and from colistine using both an ultras onic nebulizer and a jet nebulizer. Distinction between good and bad nebuli zers does not depend upon the physical process involved to nebulize the dru g, but on the intrinsic characteristics of the device and its performance w ith a known drug. The inhaled mass of ar? aerosol in the respirable range m ust be high and dosimetric nebulizers represent a significant progress. Fin ally, adminnistration of anti infections aerosols requires a new pharmacolo gical approach to monitor treatment and urinary assays are promising.