In 1955 psychiatry was dominated by psychoanalytic theory and psychoanalysts. Change occurred with empirical diagnostic criteria, but also with Miltown (meprobamate), the first broadly popular psychotropic drug. By late 1956 one in 20 Americans was taking Miltown or another tranquilizer. Pharmacies ran out of the drug before the close of one day's business. They posted signs in their windows announcing, "Out of Miltown" or "More Miltown Tomorrow." Miltown's success was followed by the success of other agents. In the early 1970s, one in ten Americans was taking Valium (diazepam). By 1994 Prozac was the second-best-selling drug in the United States, after Zantac (ranitidine).