A chronic lack of opioid drugs leaves millions of people throughout the developing world to live and die in unrelenting, excruciating pain. It is a particularly bitter irony in India, which historically had the world's biggest legal opium poppy industry.

The Lancet journal has dubbed the lack of access even to cheap pain killers such as morphine a "medical, public health, and moral failing". Justin Rowlatt reports from Kerala, where Dr M R Rajagopal is pioneering a revolution in palliative care, including the successful lobbying of the Indian government to liberalise its draconian laws on opioids in 2014.

But where will the drugs come from? Megan O'Brien of the American Cancer Society explains a cheap solution they are advocating in Sub-Saharan Africa. And Kunal Saxena, managing director of pharma company Rusan, tells of his hopes for the privatisation and expansion of India's opium business.

Producer: Laurence Knight

(Picture: Benedict Alexander, a patient at the Pallium India clinic, with his wife Bindu; Credit: BBC)