Abstract
Maxillary sinus infections start in the mucous membrdnes. Chiefly for this reason we decided to study the concentration of penicillin-V in the maxillary sinus mucosa. 40 patients with or without maxillary sinus infections received 12.5 or 25 mg penicillin-V orally at different time intervals before operation for the removal of the sinus mucosa. The results indicate that a single oral dose of 25 mg per kg bodyweight. of the potassium salt of penicillin-V (Calciopen, Leo) gives an antibiotic concentration in the maxillary sinus mucosa in infected as well as uninfected patients which is well above the MIC for the majority of the microorganisms causing maxillary sinusitis.