A study was conducted to assess if ranitidine given once or twice a day is effective for relief of gastroesophageal reflux symptoms among pregnant women who failed conservative approaches.

Volunteers were sought who had heartburn despite antacid use among obstetrics clinic population. This was a double-blind, placebo-controlled, triple crossover study. Following a baseline week, 20 patients were randomly allocated to receive the following weekly regimens - ranitidine 150 mg twice a day, placebo in the morning and ranitidine 150 mg in the evening, or placebo twice a day. Eighteen patients completed the study.

The twice a day ranitidine regimen was found to decrease heartburn symptoms in comparison with the baseline (P < .001) or a placebo (P < .01).

When compared with ranitidine once a day, the twice-daily dosing regimen led to lesser need for antacids compared with placebo (P < .05 versus P > .05) and to the baseline (P < .001 versus P < .05).

There was a 55.6% average reduction in heartburn severity with the twice-daily ranitidine regimen, when compared with baseline, and 44.2% reduction when compared with placebo.

To conclude, ranitidine 150 mg twice daily is effective in relieving gastroesophageal reflux symptoms during pregnancy.

Source: Larson JD, Patatanian E, Miner Jr PB, et al. Double-blind, placebo-controlled study of ranitidine for gastroesophageal reflux symptoms during pregnancy. Obstet Gynecol. 1997 Jul;90(1):83-7.