Comparison of erythromycin estolate and erythromycin ethylsuccinate for treatment of pertussis. The Erythromycin Study Group.

In an open randomized multicenter study 190 culture-positive pediatric ambulatory pertussis patients were treated for 14 days with either erythromycin estolate (EST) (n = 93; 40 mg/kg/day divided in 2 doses) or erythromycin ethylsuccinate (ETH) (n = 97; 60 mg/kg/day divided in 3 doses). On day 14 Bordetella pertussis was recovered from cultures of 2 patients (2.2%) treated with EST and 1 patient (1.0%) treated with ETH. Despite the fact that 151 patients (79.4%) had reached the early paroxysmal stage at initiation of antimicrobial therapy, clinical improvement was seen in the majority (reduced frequency and severity of coughing: EST, 77.4 and 67.7%; ETH, 74.2 and 63.9%, respectively). Drug-related side effects were noted in 11 patients (11.8%) treated with EST and 16 patients (16.5%) treated with ETH (P greater than 0.05) and consisted mainly of minor gastrointestinal complaints. Erythromycin estolate in a lower dose administered only twice a day was equivalent to erythromycin ethylsuccinate in all aspects and proved to be adequate antimicrobial treatment for pertussis patients.