The prescription-only model is the most tightly controlled drug supply model currently in operation. Under this model, drugs are prescribed to a named user by a qualified and licensed medical practitioner. They are dispensed by a licensed practitioner or pharmacist from a licensed pharmacy or other designated outlet.
The process is controlled by a range of legislation, regulatory structures and enforcement bodies. These guide, oversee and police the prescribing doctors and dispensing pharmacists. They also help determine which drugs are available, in what form, where, and under what criteria.
As the most tightly controlled and enforced supply model, the prescription model is the most expensive to administer. It is limited to medical necessity, which means it tends to only be used to address the problematic or dependent end of the drug use spectrum. Most commonly, it supports heroin substitute (e.g. methadone) maintenance prescribing as part of a treatment regimen or harm reduction programme. As such it will only ever involve a small fraction of the total drug using population, although it should be noted that this user group is disproportionately associated with the greatest personal and societal harms (especially under prohibition).
While substitute opiates such as methadone are the most commonly prescribed under such scenarios, it is also used to provide prescribed, injectable heroin (diamorphine) in some cases. Heroin Assisted Treatment (HAT) has a long history, and an established evidence base as an effective harm reduction measure for people who have not achieved success with substitute opiates. Less common, although not unknown, is the prescription of stimulants, including amphetamines and cocaine.