Paediatric endocarditis prophylaxis

Clarithromycin is a macrolide. The EAPD lists it as an alternative for confirmed penicillin allergy when a child with a high-risk cardiac condition undergoes a high-risk dental procedure. Use it only after consulting the paediatric cardiologist. Its use for endocarditis prophylaxis is off-label.

The EAPD regimen is a single oral dose of 15 mg/kg, 30 to 60 minutes before the procedure. The ESC sets a maximum of 500 mg per dose. See Paediatric antibiotics for indications and other prophylactic regimens.

The calculator uses the 125 mg/5 mL (25 mg/mL) suspension from 6 months of age. Check the strength: the 250 mg/5 mL suspension requires a different volume.

QT risk and interactions

Clarithromycin is contraindicated with known QT prolongation, previous ventricular arrhythmia, hypokalaemia or hypomagnesaemia. Check for CYP3A4 interactions, including with oral midazolam and ivabradine. Seek individual assessment if there is significant renal or hepatic impairment.