A team of scientists found a new way to block addiction to heroin and morphine and increase pain relief.
The team from the University of Adelaide and University of Colorado has discovered the key mechanism in the body's immune system that amplifies addiction to opioid drugs.
Laboratory studies have shown that the drug (+)-naloxone (pronounced: PLUS nal-OX-own) will selectively block the immune-addiction response.
The results - which could eventually lead to new co-formulated drugs that assist patients with severe pain, as well as helping heroin users to kick the habit - will be published tomorrow in the Journal of Neuroscience
"Our studies have shown conclusively that we can block addiction via the immune system of the brain, without targeting the brain's wiring," says the lead author of the study, Dr Mark Hutchinson ARC Research Fellow in the University of Adelaide's School of Medical Sciences.
"Both the central nervous system and the immune system play important roles in creating addiction, but our studies have shown we only need to block the immune response in the brain to prevent cravings for opioid drugs."
The team has focused its research efforts on the immune receptor known as Toll-Like receptor 4 (TLR4).
"Opioid drugs such as morphine and heroin bind to TLR4 in a similar way to the normal immune response to bacteria. The problem is that TLR4 then acts as an amplifier for addiction," Dr Hutchinson says.