The Harrison Act authorized the practitioners to prescribe cocaine and opiates; however, the law was somehow subject to interpretation by the enforcing authorities.
The U.S. Department of Treasury viewed patient drug maintenance with the aid of these substances as being beyond medical scope, and this resulted in many physicians being arrested, jailed, and prosecuted.
Under the authority of the Harrison Act, the Internal Revenue Bureau’s Narcotic Division closed down city and state narcotic clinics and also sent the drug violators to federal penitentiaries.
And logically, this resulted in the physicians stopping their prescription of drugs that were covered under the Harrison Act, ultimately sending the users to the black market to seek out these substances.
Ironically, the enforcement agents were referred to as “narcs”, arguably first use of the current and familiar colloquialism.