Popular heartburn medications Prilosec and Nexium are commonly used to treat gastroesophageal reflux disease (GERD), gastric ulcers, duodenal ulcers, and other conditions related to excess stomach acid. Prilosec (omeprazole) appeared on the market first, and was approved for use in children as young as two years old. Nexium (esomeprazole magnesium) is approved only for adults, and is not available as a generic drug.
The U.S. Food and Drug Administration classify Prilosec as a Category C drug, indicating possible risks to a fetus when the drug is taken during pregnancy. When given to pregnant rabbits in high doses, Prilosec increased the risk of miscarriage. Nexium is placed in Category B, meaning it has yet to be determined whether the medication could possibly harm an unborn baby or cause birth defects. Physicians are advised to not prescribe either Prilosec or Nexium to nursing women, and to determine whether the risks outweigh the benefits before prescribing to pregnant women.
While these drugs used to only be available if prescribed by a doctor, Prilosec, Zegerid and Prevacid are now available for over-the-counter use without a prescription. Additionally these medications have lost patent protection and are now available under store brand names.
Although a 2010 study from Denmark published in the New England Journal of Medicine suggested that the number of children with birth defects born to women taking heartburn drugs was not statistically significant, the study also found that women who took the medications in the four weeks leading up to pregnancy had a 39% greater risk of having children with birth defects. The study looked at nearly 841,000 births registered with national databases from 1996 to 2008.