[The effect of various antibiotics on the mixed flora of the maxillary sinus in sinusitis(author's transl)].

: The effect of four frequently used antibiotics on the germs of the sinus maxillaris was studied. For this purpose germs of the sinus max. rinsing fluid, got from 127 patients, were cultured under nearly the same physical and chemical conditions which can be expected in the sinus itself. Each antibiotic substance was studied with three different comcentrations in the culture medium. By extrapolation of the linear regression between some characteristical parameters of the culture absorbancy development and the concentration, the inhibitory concentration can be estimated. The efficacy decreases in the following order: Doxycyclin greater than Gentamycin greater than Ampicillin greater than Lincomycin. An inhibitory concentration results, if the antibiotics are instilled in the sinus itself. The general side effects can be neglected but not at all the local ones. Investigations in this direction are still going on. As a preliminary report, 700 instillations of Lincomycin turned out with no incident.