Patent medicines reached peak popularity at the turn of the 20th century and were sold as cures for anything from a toothache to a full-blown cold. They were not patented but they would certainly mask symptoms because these "medicines"contained opium, morphine, and alcohol. Despite the name there was no regulation of these compounds and manufacturers intentionally suppressed the true ingredients of their remedies. The ads were aimed at wooing new customers.
Much more: Atlas Obscura