"The emerging consensus is that heroin is a treatment for a limited number of illicit-drug users who do not do well with other medicines. Historically, however, heroin was the main 'drug of choice' for treatment. In the 1920s and earlier in Britain, it was the treatment or maintenance drug for compliant middle-class addicts, those who accepted the authority of the doctor to prescribe to them. The prescription of heroin was the basis of the so-called British system, which operated until the 1960s.6 This was not the case in the United States. The inability to conduct the NAOMI trial in the United States reflects a historically different attitude toward the medical prescription of heroin to addicts; this prohibition dates back to the implementation of the 1914 Harrison Narcotics Act before World War I. Doctors were prosecuted thereafter if they prescribed heroin for addicts."
Berridge V. (2009). Heroin prescription and history. The New England journal of medicine, 361(8), 820–821. doi.org/10.1056/NEJMe0904243