Comparison of erythromycin acistrate and enterocoated erythromycin base in acute respiratory infections

The efficacy and tolerability of erythromycin acistrate (EA), a new erythromycin derivative, and enterocoated erythromycin base (EB) were studied in 183 outpatients belonging to the personnel of Helsinki University Central Hospital. The patients had acute respiratory tract infections. The dosage of EA was 400 mg tid and that of EB 500 mg tid, and the treatment period ranged from seven to 14 days. The cure rate of patients taking full courses of treatment was good in both treatment groups, 96% in the EA-(n = 81) and 93% in the EB-group (n = 73). EA caused statistically significantly (P less than 0.05) less gastrointestinal side effects than EB. These side effects were also milder in the EA- than in the EB-group. The treatment was discontinued in seven patients (7%) in the EA- and in 12 patients (13%) in the EB-group because of gastrointestinal side effects. Neither of the drugs caused clinically important elevations in liver enzymes, nor were changes observed in the laboratory safety parameters measured. EA seems thus to be as effective as and better tolerated than enterocoated EB.