Indications: susceptible infections in patients with penicillin hypersensitivity; oral infections; campylobacter enteritis, syphilis, non-gonococcal urethritis, respiratory- tract infections (including Legionnaires' disease), skin infections; chronic prostatitis; diphtheria and whooping cough prophylaxis; acne vulgaris and rosacea.

Caution neonate under 2 weeks (risk of hypertrophic pyloric stenosis); predisposition to QT interval prolongation (including electrolyte disturbances, concomitant use of drugs that prolong QT interval); porphyria; hepatic impairment; renal impairment; pregnancy and breast-feeding.

Side Effects: nausea, vomiting, abdominal discomfort, diarrhoea (antibiotic-associated colitis); less frequently urticaria, rashes and other allergic reactions; reversible hearing loss after large doses; cholestatic jaundice, pancreatitis, cardiac effects (including chest pain and arrhythmias), myasthenia-like syndrome, Stevens- Johnson syndrome, and toxic epidermal necrolysis.

Dose: By mouth, ADULT and CHILD over 8 years, 250– 500 mg every 6 hours or 0.5–1 g every 12 hours up to 4 g daily in severe infections;

NEONATE 12.5 mg/kg every 6 hours;

CHILD 1 month–2 years 125 mg every 6 hours, 2–8 years 250 mg every 6 hours, doses doubled for severe infections.

Early syphilis, 500 mg 4 times daily for 14 days Uncomplicated genital chlamydia, non-gonococcal urethritis, 500 mg twice daily for 14 days

By intravenous infusion, ADULT and CHILD severe infections, 50 mg/kg daily by continuous infusion or in divided doses every 6 hours; mild infections (oral treatment not possible), 25 mg/kg daily;

NEONATE 30–45 mg/kg daily in 3 divided doses.