Clinical and pharmacological evaluation of erythromycin ethylsuccinate in patients with chronic bronchitis

SummaryA clinical and pharmacological evaluation of erythromycin ethylsuccinate was carried out in 20 patients with acute exacerbations of chronic bronchitis. Administration of a 1 g dose after a meal on Day 1 produced serum concentrations of 3.36 μg/ml after 60 min and 3.12 μg/ml after 90 min. Serum levels on Day 4 of treatment with 1 g 4-times daily showed an accumulation of erythromycin, concentrations of over 4 μg/ml being found at 1 to 2 hours after the first dose. Twelve of the 15 patients with microscopic evidence of pus in the sputum and positive for H. influenzae (12) and/or pneumococci (5) showed a satisfactory response to treatment, as did the other 5 patients with negative cultures. In the 3 patients who failed to respond clinically, H. influenzae was still present on culture and the sputum remained purulent. In 2 patients regarded as clinically cured, the sputum was mucoid but H. influenzae persisted. There was no evidence of patient intolerance of treatment with erythromycin ethylsuccinate.