Penetration of erythromycin through respiratory mucosa. A study using secretory otitis media as a model.

This study is based upon the concept that the respiratory mucosa reacts in a uniform manner to an inflammatory stimulus. Secretory Otitis Media (SOM) may be used as a model to disclose some aspects of antibiotic penetration. Erythromycin was given for different periods of time to 108 cases of SOM where myringotomy was indicated. The middle ear effusion was aspirated and blood samples were obtained simultaneously. The concentration of erythromycin was determined by microbiological procedures. Erythromycin penetrated into the middle ear effusion. After the fourth dose the concentration was at the same level as the plasma peak level. The elimination of the drug from the middle ear secretion was considerably prolonged compared with the rapid elimination from plasma. This implies that erythromycin attains a steady state in the middle ear effusion with concentrations equal to the plasma peak level.