The penetration of minocycline into human sinus secretions.

The mean minocycline content of sinus secretions aspirated during antral wash-out in 8 patients sinusitis was found to be 1.06 mug. per ml. (SD.1.03). This exceeds the M.I.C. for most strains of bacteria likely to be found in sinusitis. The mean minocycline serum level in these 8 patients was 3.16 mug. per ml. (S.D. 1.64). The sinus secretion to serum level ratio was therefore 0.34:1. No correlation was found between serum level and sinus secretion level, nor could any of the factors looked at in this study be correlated with the degree to which minocycline penetrated the sinus secretion.