Effect of methylxanthines on periodic respiration and acid gastroesophageal reflux in newborn infants

The treatment of neonatal apnea and bradycardia with methylated xanthines--theophylline and caffeine--is generally accepted. Besides the desired effects of these drugs they induce a wide range of side effects including relaxation of smooth muscles and increased gastric secretion. The aims of this study were, at first to investigate the coincidence of periodic breathing (PA) and acid gastro-esophageal reflux (GER) in neonates (n = 15) without therapy; at second to examine the influence of the consecutive medication with theophylline and caffeine on these parameters in patients (n = 10) with recurrent episodes of bradycardia and apnea. A 24 h esophageal pH-monitoring and 24 h cardiorespirography were performed simultaneously under standarized conditions. In the 15 neonates studied a weak correlation was found between the time spent breathing periodically and the duration of GER; the overlap of PB and GER was minimal. Theophylline and caffeine medication resulted in a marked reduction of PB which was more pronounced than it could be expected from maturation. The total time of a 24 h esophageal pH-monitoring was subdivided in an early postprandial time (FPP: first two hours after the beginning of a meal) and a late postprandial time (SPP: remaining time until the following meal). An increased duration of acid GER was observed during the SPP under therapy with theophylline and even more distinct with caffeine treatment.