Painkillers have been mentioned in the news again recently for all the wrong reasons. The widespread use of opioids to treat pain frequently prompts concerns about addiction and even deaths. So, why are these sometimes dangerous drugs still being given to people?
Opioids work by combining with receptors in the brain to reduce the sensation of pain - and they are highly effective.
In the US, the increasingly widespread prescription of opioids to treat long-term pain has led to an epidemic of addiction. In 2016, a record11.5 million people in the US misused prescription opioids, and there were 42,249 deaths from overdoses.
In England, GP's prescribed 23.8 million opioid-based painkillers in 2017 - a rise of 10 million prescriptions since 2007. More than 2 million working-age people were thought to have taken a prescription painkiller that was not prescribed for them in 2016-17.
Despite their benefits, the problems associated with these medicines are clear. For decades, scientists have tried to develop opioids that work without causing the problems of addiction and misuse. Better education and training might be one way to make sure they are used appropriately for those who might benefit, so that potential harms are avoided.