C. diff Risk


Oral Bioavailability


Approximate Cost


General Pediatric

30-50 mg/kg/24h PO divided q6-8h
Maximum: 2 g/24h

15-50 mg/kg/24h IV divided q6h
Maximum: 4 g/24h


250 -500 mg PO q6h

General Information

Common Usage

Pertussis, Chlamydial infections, mycobacterial infections, latency in pregnancy

Drug Monitoring

Monitor QTc in patients with increased risk.

Adverse Effects

  • GI upset, diarrhea

  • Prolongation of QTc interval

Major Interactions

Substrate of CYP3A4. Multiple CYP450 interactions possible - consult a pharmacist for more detail. May increase digoxin, carbamazepine level. Caution with QTc prolonging medications

Additional Information

Erythromycin use has been associated with an increased risk of hypertrophic pyloric stenosis in term infants less than 14 days of age.


Antimicrobial class: Macrolide

Route of Elimination: Primarily hepatic