Summary

Little evidence is available on the pharmacokinetics of antituberculous medication in premature infants. We report rifampicin (RMP) pharmacokinetics in an extremely premature, low-birthweight female infant born to a mother with known miliary tuberculosis. Intravenous RMP, isoniazid (INH), ciprofloxacin and amikacin were used, as the enteral route was not possible. Area under the curve calculations revealed low average RMP concentrations at doses of 5–10 mg/kg. We review the literature with regard to the dosing regimen and therapeutic drug levels of RMP and INH in premature infants and discuss issues of management. Evidence from this case suggests 10 mg/kg/day is the minimum dose required.