Low-dose theophylline therapy in idiopathic apnea of prematurity.

The effects of theophylline at a dose of 2 mg/kg/day (with resultant serum concentrations of 2.8 to 3.9 micrograms/ml) were observed in seven premature infants with severe idiopathic apnea. The frequency of apneic episodes decreased 62 +/- 9% (SEM) and the frequency of episodes of bradycardia decreased 73 +/- 9% following 24-48 hours of this therapy. No changes in ventilatory response to CO2 resting respiratory minute volume, arterial blood gas values, resting heart rate, or serum electrolyte concentrations were observed. Theophylline at this dose appears to be a safe and effective treatment for idiopathic apnea in premature infants. It works by a mechanism other than increasing CO2 sensitivity.