First introduced in 1950 by Smith, Kline and French, Dexamyl was marketed as an antidepressant medication that did not cause agitation, and also as an anti-anxiety drug and diet drug. Amphetamine alone had previously been marketed as an antidepressant (under the Benzedrine Sulfate brand) beginning around 1938. The amphetamine in Dexamyl was intended to elevate mood, while the barbiturate was added to counter the side effects of the amphetamine. Its name is a portmanteau of dextroamphetamine and amylbarbitone.
The British Prime Minister Anthony Eden was prescribed Dexamyl; he was using it to treat abdominal pain. It has been suggested that the drug impaired his judgement during the Suez crisis. The failure of his Suez policies led to his ousting while he was recovering in Jamaica.
In Britain during the early 1960s, the drug was taken by "tired housewives", and was also abused by youths who took excessively large doses and nicknamed the triangular blue tablets "purple hearts". This became a celebrated part of the Mod subculture. The main character of the film of Quadrophenia by The Who is shown taking purple hearts at a party, then subsequently appearing to suffer an attack of amphetamine psychosis.
In the late 1960s and early 1970s, Dexamyl spansules—a clear and green capsule containing green and white "beads"—became popular as a street-drug upper nicknamed "Christmas trees," a reference to its appearance.
The Bureau of Narcotics and Dangerous Drugs and the Food and Drug Administration decided to recall all diet drugs that contained amphetamines and required all of them to be off the market by June 30, 1973. Smith, Kline & French, the producer of Dexamyl and Eskatrol, was excepted from an order banning interstate shipment of its drugs. The company asked for a hearing before the F.D.A.
In his autobiography My Life of Absurdity, Chester Himes writes of his use of Dexamyl in the mid-1950s. He also writes that he stopped taking the pill after his friend Vandi Haygood died from "steady doses of Dexamyl."
Dr. George C. Nichopoulos was indicted in May 1980 for having improperly prescribed Dexamyl and Preludin to the singer Jerry Lee Lewis, despite knowing he was addicted to them. Dr. Patrick A. Mazza, team physician for the Reading Phillies, said he prescribed Dexamyl, Eskatrol, Dexedrine, and Preludin for Steve Carlton, Larry Christenson, Tim McCarver, Pete Rose, Larry Bowa, and Greg Luzinski. The charges against Mazza were dropped after he contended that he had provided the prescriptions in good faith to the baseball players at their request. The pill was noted writer Terry Southern's drug of choice for many years.
- Amfecloral, a single molecule with a similar effect (due to metabolites)
- Desbutal, another pharmaceutical drug containing an amphetamine and a barbiturate.
- D-IX, an experimental drug containing methamphetamine, cocaine & oxycodone
- The 1966 Kinks song "Big Black Smoke" makes reference to the drug with the lyric "And every penny she had was spent on purple hearts and cigarettes."
- The Primrose To Drug, Charleston, West Virginia Sunday Gazette-Mail, March 28, 1965, Page 54.
- Rasmussen, Nicolas, On speed : the many lives of amphetamine, New York University Press, (New York), 2008, pp.172–173.
- U.S. Sets Diet Drug Recall In Drive on Amphetamines, New York Times, April 2, 1973, Page 73.
- Himes, Chester (1976). My Life of Absurdity: The Autobiography of Chester Himes Volume II. Garden City, New York,: Doubleday & Company. p. 19.
- Presley Doctor Indicted on Drugs, New York Times, May 17, 1980, Page 8.
- Charges Dismissed In Phils' Drug Case, New York Times, February 5, 1981, Page B7.