Doctors are not the only people reluctant to venture into using opioids.
Many experts now also use opioids for a longer time to treat chronic pain.
The benefits of using opioids and the risks associated with their use vary among individuals.
It is important that one not attempt to use opioids while using naltrexone.
However, it is still possible to use other opioids on either treatment regime, although many people find "getting high" to be difficult or unattainable.
One of the promises is that you can use opioids off and on for breakthrough pain.
They say more long-term studies are needed to look at the risks and benefits of using opioids versus other, currently available treatments.
Twenty people were found to have been primarily using opioids other than heroin (either methadone or dihydrocodeine).
In other countries it is more common to use morphine or other strong opioids in these situations.
"You're talking about a patient with end-stage cancer who is afraid to use opioids because she's seen what addiction has done to her family," Walker says.
