[Double-blind long-term study on a combination of tetracycline, theophylline, doxylamine succinate, etafedrine, phenylephedrine and guaifenesine in chronic bronchitis (author's transl)].

The investigations presented were undertaken to find out whether a long-term treatment of chronic bronchitis with a combination of tetracycline, theophylline, doxylamine succinate, etafedrine, phenylephrine and guaifenesine could reduce the frequency of recurrent infections of the respiratory system. Out of 57 patients who all had suffered from at least one exacerbation in the year preceding the trial only 12 showed clinical signs of an ixacerbation during the study. 12 exacerbations occurred during the placebo phase, 6 during the treatment with Ditenate Tetra. It is specified why such a long-term treatment with an antibiotic should be reserved only for patients who are especially endangered by the exacerbation. The results of numerous microbiological investigations of sputa, nose and throat swabs before and during the long-term study are interpreted under certain aspects and questioning.