ANTACIDS FOR POSTOPERATIVE STRESS-ULCER P ROPHYLAXIS IN YOUNG INFANTS- A DOSE-FINDING STUDY

In the prophylaxis of stress ulcers with antacids in young infants the re are no recommandations of dosages that consider the physiologic mat uration of gastric acid secretion. During the first six month of life the amount of gastric acid secretion in relation to body weight and bo dy surface area increases exponentially. Therefore adult dosages of an tacids cannot be transferred to infants.Methods In a cross over study 12 infants aged be tween 4 and 174 days, who had been undergoing a car diosurgical intervention with the heart lung machine, were treated dur ing 48 hours with 2 different antacid regimens over a period of 24 hou rs each, monitoring the gastric pH continuously. The used antacid cons isted of a aluminium-magnesium complex (Al(OH)(3), 90 mg/ml and Mg(OH) (2), 60 mg/ml): Regimen A: 6 x 0.5 ml per kg body weight. Regimen B: 0 .25 ml per kg body weight at a gastric pH less than 3, with the pH rea d every 30 minutes. Results Compared to 28 applications under regimen B, 72 single doses were given under regimen A, 58 of them at a gastric pH of higher than 3. Thus, the mean administered dose was significant lower under regimen B (2.2 ml) than under regimen A (12.0 ml). Conseq uently, the mean level of gastric pH was higher under regimen A (media n: 5.96 +/- 1.31 versus 4.94 +/- 1.16). pH-values lower than 3 were mo re often measured under regimen B, whereas the phases at this pH-level were longer under regimen A. Conclusion The usual body weight related dosage of antacids seems to be to high for-early infancy. In the face of the discrepancy of the administered antacid quantity comparing reg imen A with regimen B, it seems to be reasonable for the studied age g roup to reduce the single antacid dose to 0.25 ml/kg body weight while adhering to a high application frequency of 6 times a day.