Libby Brooks (Never mind the evidence – a drug-free world is nigh, 5 March) rightfully decries the devastation the global "war on drugs" has wrought on millions of people worldwide, through mass incarceration of users, denial of life-saving health services and crop eradication. But the "war on drugs" has other victims who deserve our urgent attention: people suffering from severe pain.

Almost 50 years ago the UN agreed that states must ensure availability of narcotic drugs for the "relief of pain and suffering". Yet that promise remains a dead letter for 80% of the world population. According to the World Health Organisation, tens of millions of people suffer from severe pain without access to treatment, even though pain medications are safe, effective and inexpensive.

As a recent Human Rights Watch report documented, the near-exclusive focus on cracking down on illicit drug use has led many countries to neglect their obligation to ensure people can benefit from the medicinal qualities of narcotic drugs.