DOSE-RESPONSE STUDY OF METOCLOPRAMIDE IN GASTROESOPHAGEAL REFLUX IN INFANCY

Twenty-four infants, 1 to 18 months-old, who were referred to four centers for suspected gastroesophageal reflux and whose esophageal pH after a standard formula meal given at 9 to 10 am (Ho-day 1) fulfilled the criterion of being < 4 for more than 5% of the time between H-1 and H-6, entered a double-blind placebo-controlled dose-response trial of metoclopmmide (M). Twenty-four hours later (day 2), patients were randomly assigned to receive either placebo or a single 0.1, 0.2, or 0.4 mg/kg dose of metoclopramide, 30 min before the formula meal (n = 6/group) and the procedure was repeated. Metoclopramide plasma concentration was measured 1 h after dosing (C1h). On day 1, the time during which the esophageal pH was < 4 (time pH < 4), and five other parameters, were not significantly different in the treatment groups. On day 2, time pH < 4 (m(SD)) decreased from 33(13) to 30(33), 39(27), to 36(47), 42(15) to 18(13) and 48(25) to 31(46) min in the placebo, 0.1, 0.2, and OA mg/kg metoclopramide groups, respectively. Possibly due to the large interindividual variability, no significant differences in parameters were observed between the different groups. None of the parameters correlated with the metoclopramide dose. Time pH < 4 expressed as the difference between day 1 and day 2, relative to day 1, decreased significantly as a function of C1h. No side effects were observed. A similar study should be performed after repeated dosing regimen.