According to a study published in Acta Anaesthesiologica Scandinavica, oral ranitidine is effective in reducing gastric acidity in children.

Goudsouzian and Young evaluated the effect of preoperative administration of oral ranitidine on intragastric pH and volume of aspirate in anesthetized children aged 3-13 years. The children were divided into five groups of eight children each. The first group served as control. Groups 2 to 5 were given 2, 2.5, 3, and 3.5 mg/kg ranitidine, respectively. The drug was administered 1-4 h prior to surgery. Investigators assessed intragastric pH and volume of aspirate every hour.

• At first evaluation, ranitidine was found to be significantly effective (P < 0.001) in increasing the pH of intragastric contents to above 2.5 in 94% of the children.
• At the second measurement after one hour, it was effective in all the study children. The values of intragastric pH at the first and second evaluation are summarized in table below.
• There appeared to be no significant effect on the volume of gastric aspirate.

Table. Mean (+ s. e. mean) intragastric pH in study participants

It was concluded that oral ranitidine at doses of 2-3.5 mg/kg is an effective regimen to reduce gastric acidity in children.

Source: Goudsouzian NG, Young ET. The efficacy of ranitidine in children. Acla Anaesthesiol Scand. 1987;31:387-390.