Bromo-Seltzer (original) (raw)

Bromo-Seltzer was a brand of antacid formulated to relieve pain occurring together with heartburn, upset stomach, or acid indigestion. It originally contained sodium bromide and acetanilide, both toxic substances which were eventually removed. Its final formulation contained the pain reliever acetaminophen and two reactive chemicals—sodium bicarbonate and citric acid—which created effervescence when mixed with water. Sodium bicarbonate is an antacid.