Cure for Heroin Addiction on the Horizon

California scientists at the Scripps Institute have found a possible vaccination that may cure lab rodents that are addicted to heroin.

The potential cure helped to dull the pain-killing property in the powerful narcotic, and it showed signs of blocking the addictive nature of heroin. The vaccine, however, did not offer pain relief for many other opiates.

The original lab experiments of a heroin vaccine were published in 1974. Since then, scientists have developed vaccines against nicotine, cocaine and amphetamines. Although both nicotine and cocaine vaccines have gone as far as human tests, none have been licensed for commercial use.

The vaccines work by stimulating the immune system to make antibodies against the addictive compounds. The antibodies bind those compounds in the bloodstream and prevent them from entering the brain, where they exert their euphoric and addictive effects.

Researchers have found developing a heroin vaccine particularly challenging because the drug metabolizes quickly into other compounds after entering the body. Therefore, such a vaccine would have to impact three different compounds.

Kim Janda, a chemist at the Loa Jolla-based Scripps Research Institute, has led the team of scientists working on the heroin vaccine.

Janda said, ''Our vaccine goes through a dynamic process where it slowly changes in form from heroin to 6AM to morphine." He added, ''The immune system recognizes each of those molecules.''

To test the results of the vaccine, scientists exposed rats' paws to a hot surface or sharp objects to determine if their pain-killing functions were still intact after taking heroin. The researchers also found the rodents did not continue to press their heroin lever in order to fuel their addiction after taking the vaccine.

The Scripps Institute heroin breakthrough was reported in the Journal of Medicinal Chemistry.