Clinical pharmacology of azithromycin in infants and children

Azithromycin is the most active macrolide antibiotic. It is an azalide antibiotic. Azithromycin inhibits protein synthesis by binding reversibly to 50S ribosomal subunity. Azithromycin is bacteriastatic, but may be bactericidal, at high concentrations. This antibiotic is used for treating respiratory tract infections caused by common pathogens of community-acquired pneumoniae. Azithromycin is active against streptococci, gram-positive bacilli, Clostridium perfringens, Corynebacterium diphtheria, Listeria monocytogenes, Haemophilus influenzae, Neisseria meningitis, Neisseria gonorrhoea, Bordetella pertussis, Campylobacter jejuni, Mycoplasma pneumoniae, Legionella pneumophila, and Vibrio cholera. In infants, azithromycin dose is 10 mg/kg for treating and preventing diseases. In children, azithromycin dose ranges from 10 to 30 mg/kg. A loading dose of 500 mg is given on the first treatment day, and then 250 mg once-daily is given for days 2 through 5 for the treatment of community-acquired pneumoniae, pharyngitis, and sinusitis. Azithromycin has a long half-life, of approximately 80 hours, and thus it is administered once-daily. Much of azithromycin undergoes biliary excretion, and the rest is inactivated in the liver. This antibiotic is efficacy and safety in infants and children, and has limited side-effects in this population. Azithromycin reduces the mortality rate, and prevents illness in infants and children. Azithromycin pharmacokinetics has been extensively performed in infants and children. After azithromycin intravenous administration, the mean clearance and distribution volume are 0.15 L/h/kg, and 13 L/kg, respectively, in infants. After oral administration, Tmax is 2 hours, and the mean Cmax, AUC0-24 hours and, clearance are 230 ng/ml, 1,841 ng.h/ml, and 3.03 L/h/kg, respectively, in children. Azithromycin trials have been extensively investigated in infants and children. The aim of this study is to review the published data of azithromycin effects, metabolism, pharmacokinetics, and bacteria-resistance in infants and children.