EFFECT OF CLARITHROMYCIN ON SPUTUM PRODUCTION AND ITS RHEOLOGICAL PROPERTIES IN CHRONIC RESPIRATORY-TRACT INFECTIONS

Macrolide antibiotics possess a variety of actions other than antimicr obial activities, To determine the effects of Long-term administration of clarithromycin (CAM) on the amount and physical properties of sput um in patients with clinical conditions associated with excessive airw ay secretions, we conducted the present study in a parallel, double-bl ind, placebo-controlled fashion, Patients were divided into two groups : the first group (n = 16) received CAM (100 mg, twice a day) for 8 we eks, and the second group (n = 15) received placebo, In evaluating air way secretion, the daily amount of expectorated sputum, solid composit ion, viscoelastic properties (including elastic modulus and dynamic vi scosity), and sputum microbiology were assessed, CAM decreased sputum production from 51 +/- 6 to 21 +/- 3 g/day after treatment, whereas pl acebo had no effect, The bacterial density and sputum flora were unalt ered, In the group receiving CAM, the percent solid composition and el astic modulus increased from 2.44% +/- 0.29% to 3.01% +/- 0.20% and 66 +/- 7 to 87 +/- 8 dyne/cm(2) (P < 0.05), respectively, but the dynami c, viscosity remained unchanged, These results suggest that long-term treatment with CAM reduces the amount of sputum production, probably b y inhibiting airway secretions, and increases sputum elasticity.