Proton pump inhibitors (PPIs) — a class of heartburn drugs that includes Nexium, Prilosec and Prevacid — may increase the risk of stroke, according to research presented at the American Heart Associations’ Scientific Sessions 2016.

Dr. Thomas Sehested of the Danish Heart Foundation in Copenhagen Denmark — the study’s lead author — presented his findings at the Scientific Sessions held on Nov. 12 to 16 in New Orleans, Louisiana.

PPIs are some of the most commonly used drugs in the U.S.