Bromo-Seltzer (acetaminophen, sodium bicarbonate, and citric acid), is an antacid used to relieve pain occurring together with heartburn, upset stomach, or acid indigestion. Originally produced by inventor Isaac E. Emerson's Emerson Drug Company of Baltimore, Maryland, Bromo-Seltzer is sold in the United States in the form of effervescent granules which must be mixed with water before ingestion.
In the days of classic radio, it was known for its slogan which was repeated rhythmically in imitation of a railroad steam engine: "BRO-mo-Selt-zer, BRO-mo-Selt-zer, ..." There is also a clock tower in Baltimore, Maryland, known as the Bromo-Seltzer Tower, which has the name written on the face of the clock in lieu of the hours. Patterned on the Palazzo Vecchio in Florence, Italy, it is listed on the National Register of Historic Places.
The product took its name from a component of the original formula, sodium bromide; it contained 3.2 mEq/teaspoon of this active ingredient. Bromides are a class of tranquilizers that were withdrawn from the American market in 1975 due to their toxicity. Their sedative effect probably accounted for Bromo-Seltzer's popularity as a hangover remedy. Early formulas also used Acetanilide as the analgesic, a known poisonous substance.[1]