Metabolic and respiratory effects of theophylline in the preterm infant

Arch Dis Child Fetal Neonatal Ed. 2000 Jul;83(1):F39-43. doi: 10.1136/fn.83.1.f39.


Background: Methylxanthines are often administered to preterm infants for the treatment of apnoea.

Aims: To study the effects of theophylline on energy metabolism, physical activity, and lung mechanics in preterm infants.

Methods: Indirect calorimetry was performed for six hours before and after administration of a bolus of theophylline (5 mg/kg) in 18 preterm infants while physical activity was recorded with a video camera. Lung mechanics measurements were performed at baseline and 12 and 24 hours after theophylline treatment.

Results: Theophylline increased mean (SEM) energy expenditure by 15 (5) kJ/kg/day and augmented carbohydrate utilisation from 6.8 to 8.0 g/kg/day, but fat oxidation was unchanged. After theophylline treatment, preterm infants had faster respiration, lower transcutaneous CO2, and improved static respiratory compliance without increased physical activity.

Conclusions: A bolus of 5 mg/kg theophylline increased energy expenditure independently of physical activity, increased carbohydrate utilisation, and improved respiratory compliance. The increased energy expenditure could be detrimental to the growth of the preterm infant.

Publication types

  • Clinical Trial

MeSH terms

  • Aminophylline / pharmacology
  • Bronchodilator Agents / pharmacology*
  • Calorimetry, Indirect
  • Energy Metabolism / drug effects*
  • Heart Rate / drug effects
  • Humans
  • Infant, Newborn
  • Infant, Premature / physiology*
  • Phosphodiesterase Inhibitors / pharmacology*
  • Physical Exertion / drug effects
  • Pulmonary Gas Exchange / drug effects
  • Respiratory Mechanics / drug effects
  • Theophylline / pharmacology*


  • Bronchodilator Agents
  • Phosphodiesterase Inhibitors
  • Aminophylline
  • Theophylline