Dose and Administration

	Dose
Preterm neonates	5-20 mg/kg/dose 12 hourly PO
Term neonates:≤7 days	10-20 mg/kg/dose 12 hourly PO
Term neonates: >7 days	10-20 mg/kg/dose 8 hourly PO
Infants	10-20 mg/kg/dose 6 hourly PO

Administer with EBM/infant formula to enhance absorption and reduce possible gastrointestinal side effects.

Indications

Suspected/proven infection with Mycoplasma pneumoniae, Ureaplasma urealyticum, and Chlamydia trachomatis.
As a substitute for penicillin in situations of significant hypersensitivity to penicillin.
Treatment for and prophylaxis against Bordetella pertussis.

Contraindications and Precautions

Known hypersensitivity to erythromycin or other macrolides.
Infants with biliary tract obstruction.
Caution in preterm infants, especially extreme immaturity.
Caution in infants with jaundice, liver dysfunction, and biliary tract disease.

Clinical Pharmacology

Bacteriostatic antibiotic which suppresses bacterial protein synthesis. The antibacterial spectrum is similar to penicillin but extended to include Mycoplasma pneumoniae, Ureaplasma urealyticum and Chlamydia trachomatis.

Vd 45% of body weight in adults. Antibacterial levels are achievable in all tissues except brain and CSF. Highly bound (64-98%) to human plasma protein. Hepatic excretion into bile as active compound. Only 5-15% of administered dose excreted in the active form in the urine. Limited data are available for pharmacokinetics in neonates. It is reported that the drug is well absorbed by mouth. Plasma half life is 2-4 hours.

Interactions

Increase serum digoxin levels.
Midazolam: increased effect.
Theophylline decreases erythromycin blood levels and increases theophylline toxicity. Effect on half life of caffeine has not been clarified.
Never give erythromycin to a baby receiving cisapride because there is a risk of arrhythmias.

Possible Adverse Effects

Gastrointestinal disturbances (nausea, vomiting, diarrhoea).
Jaundice, intrahepatic cholestasis.
Reversible hearing loss (very high doses).
Hypersensitivity reactions (urticaria, mild skin eruptions, anaphylaxis) rare.

Special Considerations

May antagonise action of penicillins, cephalosporins.
Concurrent use with theophylline, phenytoin, carbamapezine, or digoxin may be associated with elevation in serum levels of these drugs. The dose of these drugs should be reduced in infants and serum concentrations monitored closely.
Reduce dose of erythromycin if extreme immaturity, severe jaundice and/or hepatic dysfunction.
Absorption from the gastrointestinal tract is unpredictable in the very immature infant. It may be preferable to administer erythromycin intravenously initially for at least 48-72 hours, or longer, before changing to oral administration.