Dose conversion from aminophylline to theophylline in preterm infants.

Twenty two preterm infants were prospectively evaluated to assess the need for dose adjustment when converting enteral and parenteral routes of methylxanthine administration. Serum theophylline concentrations remained unchanged in 18 infants after conversion from intravenous aminophylline to theophylline by mouth with dose reduction, as is currently recommended. Intravenous aminophylline and theophylline by mouth may therefore be prescribed at equivalent doses, with a possible reduction in drug errors, and improved stability of serum concentrations.