Pain, pus and poison.

Michael Mosley tells the extraordinary story of how scientists learnt to use the world around us to conquer the common afflictions of pain, pus and poison. In the first of three programmes, Mosley discovers just what pain is, why we want to control it and how we ultimately did it. He begins by recalling Friedrich Sertürner’s experiments to isolate morphine from opium in 1815. For centuries opium was relied upon to relieve pain, but the raw material was expensive and unreliable, leading to a drive to extract the active ingredient. At UCL School of Pharmacy, Mosely recreates the process using modern equipment. Sertürner’s discovery led to the extraction of other alkaloids from plants and the birth of modern pharmaceuticals. Mosley then considers the physiology of pain and how opiates act to block it. Although effective, their side effects prompted a search for alternatives, leading to the discovery of cocaine (extracted from coca leaves). Freud described cocaine as a ‘magical substance’ and sent samples to colleagues. One of these, eye surgeon Karl Koller, discovered the drug’s effectiveness as a local anaesthetic – demonstrated in footage of a cataract operation on a conscious patient in 1917. But more extensive surgeries could not be performed pain-free using alkaloids alone. Humphry Davy discovered through self-experimentation that nitrous oxide (laughing gas) reduced pain but its potential for use in surgery wasn’t explored until nearly 50 years later. After trying the substance at a party, the young American dentist Horace Wells began using it on patients, but a failed demonstration meant that it was not readily accepted by the medical community. His colleague William Morton was undeterred and successfully demonstrated the use of ether as an anaesthetic on a surgical patient in 1846. Stephanie Snow comments that general anaesthetics brought about a widespread reduction in social tolerance of pain. Mosely moves on to synthetic painkillers produced from coal tar. In the 1890s, German chemist Arthur Eichengrün and colleagues at Bayer chemically modified existing drugs to produce aspirin and diamorphine (heroin). Aspirin was initially overlooked in favour of heroin but after further testing went on to become one of the world’s bestselling painkillers. Mosely demonstrates how aspirin works locally using stinging nettles. The possibility of producing entirely synthetic drugs led to the production of chloral hydrate, a sleeping tablet. Mosely tries out one of its successors, barbiturate sodium thiopental, aka ‘the truth drug’. Used predominately as a general anaesthetic, the drug appears to inhibit lying as Mosely demonstrates. Chemists are now focussing on the development of new painkillers rather than anaesthetics. Michael Hayden from the University of British Columbia explains how research on individuals born without the ability to feel pain may hold the key to future drugs that will offer hope to millions.