PENETRATION OF PENICILLIN-V TO TONSILLAR SURFACE FLUID IN HEALTHY-INDIVIDUALS AND IN PATIENTS WITH ACUTE TONSILLITIS

In the treatment of group A streptococcal tonsillitis, as the bacteria are located on the epithelial surface, an important determinant of ou tcome is the concentration of penicillin in extracellular tonsillar su rface fluid. Accordingly, we investigated the concentration of penicil lin in serum, and penetration to tonsillar surface fluid and saliva in nine patients with acute group A streptococcal tonsillitis and in nin e healthy controls. Among the healthy subjects, despite high serum pen icillin concentrations (mean, 2.04 mug/ml), there was no penetration t o tonsillar surface fluid or to saliva, whereas erythromycin penetrate d to tonsillar surface fluid in 3/6 cases. Of the nine patients with a cute tonsillitis, on the first day of treatment eight manifested high concentrations of penicillin in tonsillar surface fluid (mean, 0.34 mu g/ml-i.e. well above the minimal inhibitory concentration (MIC) for gr oup A streptococci), but penetration to saliva was found in only two p atients. On the tenth day of treatment, penicillin was not present in the saliva of any of the patients and was present in the tonsillar sur face fluid of only one. The results suggest that measurable concentrat ions of penicillin in tonsillar surface fluid can only be obtained in the presence of inflammation with fluid exudation through the tonsilla r epithelium.