Evaluation of pertussis treatment with erythromycin ethylsuccinate and stearate according to age.

Although erythromycin estolate has been fully assessed for pertussis treatment, the evaluation of erythromycin ethylsuccinate and stearate, the main erythromycin preparations used in Japan and the US, is inadequate. We evaluated these preparations to establish an appropriate treatment for pertussis according to age. Sixty-six patients with culture-confirmed pertussis were treated with erythromycin administered at a dosage of 40-50 mg/kg/day (maximum, 1.2 g/day). Negative culture was obtained in 39% (15/38) of patients aged 0-2 years within one week and in 71% (27/38) within two weeks, in 78% (7/9) of those aged 3-15 years within one week and in 100% (9/9) within two weeks. All 12 adult patients had a negative culture within one week. The efficacy of erythromycin for the eradication of B. pertussis was significantly lower in children aged 0-2 years than in older children. In conclusion, it is desirable to administer erythromycin for three weeks to children aged 0-2 years, two weeks to those aged 3-15 years and one week to adults.