Drug Can Block Addiction to Morphine and Heroin

An international team of scientists from the Universityof Adelaide and the University of Coloradohave uncovered a drug that will block addiction to morphine and heroin without affecting pain relief.

“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.

Basically, researchers have discovered that the drug (+)-naloxone (pronounced: PLUS nal-OX-own), created by Dr. Kenner Rice in the 1970s, selectively blocks the immune-addiction response to prevent cravings.

The drug is a variant of naloxone, which is an opioid inverse antagonist used to counter the effects of opiate overdose, specifically to counteract life-threatening depression of the central nervous system and respiratory system.

Researchers paid close attention to 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.

The drug (+)-naloxone changes the neurochemistry in the brain so that opioids can no longer produce the dopamine needed to generate addiction, yet the pain-relieving affects of these drugs are retained. For example, if both morphine and (+)-naloxone are taken simultaneously, a patient can receive the necessary analgesic effect of the morphine but avoid the potential for addiction.

Senior author Professor Linda Watkins, from the Center for Neuroscience at the University of Colorado Boulder, says: “This work fundamentally changes what we understand about opioids, reward and addiction. We’ve suspected for some years that TLR4 may be the key to blocking opioid addiction, but now we have the proof.

These results could lead to the production of better formulated medications to prevent addiction and assist heroin and morphine users in kicking their habit.

Scientists Can Now Block Heroin,Morphine Addiction
Naloxone