Influence of xanthines on gastroesophageal reflux in infants at risk for sudden infant death syndrome.

Theophylline and caffeine are two drugs frequently administered to infants at risk for sudden infant death syndrome, because of their stimulatory effects on the respiratory system. These drugs are known to increase gastric acid secretion and to decrease lower esophageal sphincter pressure that, in turn, possibly increases gastroesophageal reflux (GER). Thirty babies were tested for GER before and during caffeine treatment. Eighteen were studied under the same conditions while undergoing theophylline treatment. All results of pH monitoring before treatment were within normal ranges. Episodes of GER increased significantly (P less than .001) in about 50% of the group treated with caffeine and in 66% of the group treated with theophylline. These results were independent of plasma xanthine concentrations (within or below therapeutic ranges) and of the efficacy of the drug. In addition, an increase was noted for the number of episodes of GER in 24 hours (from 5.3 to 17.1 in the caffeine group and from 5.3 to 24.3 in the theophylline group) and for the time pH was less than 4 (from 0.87% to 6% in the caffeine group and up to 13% in the theophylline group). Because GER is another known risk factor for sudden infant death syndrome, the administration of xanthine derivatives in babies at risk for sudden infant death syndrome should be carefully considered in each case.