A study was designed to determine the pharmacokinetics and pharmacodynamics of a single dose of over-the-counter ranitidine 75 mg in children having symptoms of gastro-esophageal reflux disease (GERD).

Children aged 4 to 11 years with symptoms of heartburn suspected to be associated with GERD were evaluated at six clinical centers. Nineteen children received a single dose of oral ranitidine 75 mg and 10 received placebo. Intragastric pH and serial blood sampling were done for 6 h after dosing.

Study findings –

• Median Cmax of 477 ng/mL was noted within a median of 2.5 h following dosing.
• Median half-life was 2.0 h.
• Intragastric pH started increasing about 30 min after dosing with ranitidine to a peak of ˜
• The pH in the group that received ranitidine remained higher than that in the placebo group all through the 6-h period.

The study concluded that ranitidine 75 mg led to a significant increase in intragastric pH in children. The pharmacokinetic and pharmacodynamic profiles appeared to be similar to those seen in adults. Ranitidine is an effective agent to control intragastric acidity children aged 4-11 years.

Source: Orenstein SR, Blumer JL, Faessel HM, et al. Ranitidine, 75 mg, over-the-counter dose: pharmacokinetic and pharmacodynamic effects in children with symptoms of gastro-oesophageal reflux. Aliment Pharmacol Ther. 2002;16(5):899-907.