Doxycycline in respiratory tract infections. Report of a retrospective study in Spain during the winter 1972-1973.

In the winter of 1972-1973 a multicentre trial of the treatment of upper and lower respiratory tract infections was carried out in Spain using doxycycline. 85 physicians participated in the study and treated 1,653 patients. The infections included acute bronchitis, acute exacerbation of chronic bronchitis, pneumonia, bronchopneumonia, tonsillitis, pharyngitis, trachetis, sinusitis, and otitis media. The majority of the patients were adult out-patients although some children and adolescents were included: 1,011 of the patients were male and 642 female. A number of the signs of respiratory infection such as temperature, cough, pain and inflammatory symptoms were examined. A rapid reduction in intensity and severity was noted in all of these parameters. Tolerance to the antibiotic was excellent. Only minor side-effects were reported and these were mild and mainly limited to the gastro-intestinal tract - in no case was treatment discontinued. The total number of side-effects was 37; they occurred in 31 out of the 1,653 patients. The overall evaluation of results showed a very good or good response in 85% of the patients. It appears from this multicentre study that the efficacy of doxycycline has in no way decreased over the 7 years of its extensive use in Spain. It remains a fast acting and effective antibiotic in upper and lower respiratory tract infections irrespective of age, sex or diagnosis.