Effects of iodopropylidene glycerol on tracheobronchial clearance in stable, chronic bronchitic patients.

We carried out a randomised, double-blind, two-period crossover study in 15 stable, chronic bronchitics to ascertain the effect on tracheobronchial clearance (TBC) of 1 week's treatment with iodopropylidene glycerol (IPG-Organidin), two tablets four times daily compared to matched placebo. TBC was measured by radioaerosol technique. The drug did not significantly alter TBC in the group as a whole but did significantly enhance TBC in 6 patients who expectorated during both placebo and IPG 6-h observation periods. In 4 patients who did not expectorate in either period no change in TBC occurred. In 10 patients who expectorated in either one or both observation periods, a significant positive correlation was found between an index of the patients' sputum produced and improvement in TBC following IPG treatment. IPG can be an effective expectorant in patients with mucus hypersecretion and particularly so in patients with copious sputum production.