[ deep inhale ] claritin-d. get more airflow. did you know prilosec otc can stop frequent heartburn before it begins? heartburn happens when stomach acid refluxes into the esophagus. prilosec otc uses a unique delayed-release formula that helps it pass through the tough stomach acid. it then works to turn down acid production, blocking heartburn at the source. with just one pill a day, you get 24-hour heartburn protection.