Metabolic effects of theophylline in preterm infants.

A loading dose of theophylline produces significant metabolic changes, including increase of plasma glucose concentration and an early rise in serum insulin in some infants. The chronic effects of theophylline on plasma glucose, serum insulin, and glucagon are not known at this time. The potential for development of metabolic derangements must be kept in mind when theophylline is used for protracted periods in premature infants.