[Indomethacin inhalation therapy for patients with excessive sputum]

We studied the effect of indomethacin (INDO) inhalation therapy on patients with excessive sputum due to chronic respiratory infection. INDO (3.5 x 10(-2) M) reduced sputum production from 211 +/- 43 to 106 +/- 22 ml/day (p less than 0.05, n = 7), the effect that was more remarkable in patients with diffuse panbronchiolitis (DPB). The prostaglandin E2 (PGE2) levels in sputum were also decreased significantly. In addition, to elucidate the mechanism of action of INDO on epithelial ion transport, we measured short-circuit current (Isc) of canine tracheal epithelium in response to 3 x 10(-6) M INDO under short-circuit conditions in vitro. Addition of INDO to mucosal medium decreased Isc from 42.8 +/- 6.0 to 8.2 +/- 3.5 microA/cm2 (p less than 0.01, n = 6). The increases in Isc produced by PGE2 and PGF2 alpha were abolished by furosemide, a Cl-transport blocker. These results suggest that INDO inhalation is a promising therapy in improving excessive sputum production, and that this effect may be attributed to inhibition of PGE2-dependent Cl-secretion into the airway lumen.