Erythromycin acistrate and erythromycin stearate in the treatment of non-gonococcal urethritis

: The antibacterial efficacy and tolerability of erythromycin acistrate (EA) and erythromycin stearate (ES) were compared in 100 male patients with non-gonococcal urethritis (NGU). The dosage of EA was 400 mg tid and that of ES 500 mg tid. Mean duration of treatment was ten days. When the final evaluation of the trial was made, the patient material was divided into two groups. One group consisted of patients with chlamydia-positive culture before treatment, the other of chlamydia-negative patients with signs of infection in the direct smear. There were 17 patients with chlamydial infection in the EA-group, and the microbiological cure rate was 100%. In the ES-group there were 21 patients with chlamydial infection and the microbiological cure rate was 95%. In the EA-group, the cure rate of chlamydia-negative NGU patients was 78%, and the corresponding figure in the ES-group was 86%. There was no difference in the cure rates between the two groups on either drug. In the EA-group, 25 patients (50%) reported side effects, in 22 these were gastrointestinal. In the ES-group, 26 patients (52%) reported side effects; in 22 these were gastrointestinal. Two patients in the EA-group discontinued the treatment because of gastrointestinal side effects. There were no differences between the groups in the frequency, severity and duration of side effects.