[Xanthines in apnea of premature infants. Influence on gastroesophageal reflux]

Theophylline and caffeine are two xanthine-derivated drugs frequently administered for their stimulating effects on the respiratory center in premature babies presenting with "idiopathic apnea". These drugs are known to increase the gastric acid secretion and to decrease the lower esophageal sphincter pressure, that in turn possibly increase gastroesophageal reflux. We studied 14 premature babies presenting with "idiopathic apnea", treated with caffeine at recommended dose (2.5 mg/kg/day). At 24 hour continuous esophageal pH monitoring was performed 3 to 5 days after starting the treatment. In 6 babies total reflux time (5.6% of the investigation time with ph less than 4) and the number of refluxes in 24 hours (15.3) were significantly increased compared to the other 8 babies (pH less than 4: 0.92%; number of refluxes 6.1). These results were also compared to the results obtained ina symptomatic full term neonates (5-10 days old) (pH less than 4: 0.87; number 5.3/24 hours). The results we obtained in the caffeine treated group were independent of the plasma xanthine levels (all within or below therapeutic ranges). A second pH monitoring 2 weeks after stopping caffeine administration was always within normal ranges. The increase of gastroesophageal reflux seems individual for each patient. Gastroesophageal reflux can lead to pulmonary aspiration, and, in this way, it can be the origin of obstructive apnea or aspiration pneumonia.