Trimethoprim prophylaxis of acute exacerbations in chronic obstructive pulmonary diseases. Five-year winter chemoprophylaxis for chronic bronchitis. Long-continued treatment with tetracycline and prednisolone in chronic bronchitis; a controlled trial.
A double-blind randomized trial was carried out to study the efficacy and tolerance of trimethoprim with a daily single dose of 300 mg in long-term prophylaxis of acute exacerbations of chronic obstructive pulmonary diseases (COPD). The patients, 13 in the trimethoprim group and 11 in the placebo group, were followed up at fixed intervals and checked for respiratory functions and haematological parameters for six months. The number of exacerbations were significantly lower than during the previous winter in both groups: 0.6 compared to 3.8 in the trimethoprim group, and 0.6 to 3.0 in the placebo group. Tolerance of trimethoprim was good and did not differ from that of placebo. The necessity of double-blind trials in evaluating the prophylactic value of antibiotics in COPD is emphasized, since the exacerbations are also dependent on many unknown factors. There were no statistically significant differences in blood counts of folate levels. Seventy-nine patients with chronic bronchitis were randomly allotted to four treatment regimens-placebo throughout the winter months for five years; tetracycline for the first two winters and placebo for the next three; placebo for the first two winters and tetracycline for the next three; and tetracycline for five winters. In addition all groups recevied a five-day course of tetracycline for any acute exacerbation. There was a significant reduction in the number of exacerbations among the more susceptible patients-that is, those who suffered more than one exacerbation each winter. Though the average decline in F.E.V.(1) over the five-year period was less in the treated groups this was not statistically significant. There was no significant difference between the groups in respect of lung volumes, diffusing capacity, and blood gases. nan
Prophylactic antibiotics in chronic bronchitis/COPD have a small but statistically significant effect in reducing the days of illness due to exacerbations of chronic bronchitis. They do not have a place in routine treatment because of concerns about the development of antibiotic resistance and the possibility of adverse effects. The available data are over 30 years old, so the pattern of antibiotic sensitivity may have changed and there is a wider range of antibiotics in use.