International control of medicines

Psychoactive substances are classified and placed under international control in compliance with three international conventions ratified by the member states of the United Nations.
The purpose of putting these substances under international control is to protect public health and minimize the diversion and misuse of harmful psychoactive substances. However, it is imperative to find a balance between the prevention of drug misuse and dependence on the one hand, and the accessibility of essential controlled medicines on the other.
The WHO Expert Committee on Drug Dependence (ECDD) is mandated by the international drug control conventions to assess the health risks and potential therapeutic use of psychoactive substances. Depending on the outcome of this assessment, the ECDD issues recommendations to the UN Commission on Narcotic Drugs (CND) in Vienna on whether a substance should be placed under international control or not.

Balancing access and prevention

Although drug control regulations are needed, if they are overly restrictive they can hamper access to controlled medicines for therapeutic use. A balance must therefore be struck between medical and regulatory requirements. To adequately address the need for pain medication and prevent potential harms, proper regulation of controlled medicines needs to be enforced.
In addition, careful initial assessment of patients prior to prescribing, regular patient monitoring and patient education and having a proper understanding and management of the differences between acute and chronic pain, are imperative. Moreover, recent research in the fields of palliative care and pain management has identified many strategies for managing pain, beyond drug treatment alone. Evaluating this new evidence and establishing best strategies for alleviating pain - both acute and chronic - is an important area of work for WHO.
More information can be found at:
UNODC provides suggestions for promoting access to controlled drugs for medical purposes at the national level in its Technical Guidance: Increasing access and availability of controlled medicines. The document focuses on the critical components essential for creating change and providing the best medical care available for patients to alleviate pain and contribute to a higher quality of life. 
The INCB report Progress in ensuring adequate access to internationally controlled substances for medical and scientific purposes shows the latest trends in the consumption of opioid analgesics and aims to assist governments develop measures to ensure the safe use and rational delivery of the best affordable medicines to the patients who need them, while preventing their diversion, misuse and abuse.