Frustrated by the high relapse rate of traditional addiction treatments, scientists are working on a strategy that recruits the body’s own defenses to help addicts kick drug habits.
The new approach uses injected vaccines to block some addictive substances from reaching the brain. If a vaccinated addict on the path to recovery slips and indulges in a drug, such as tobacco or cocaine, no pleasure will result.
“You still have to mentally say to yourself, ‘I’m not going to do this,’ but it’s so much easier to say it when you know if you light a cigarette, you’re not going to get any pleasure out of it,” says Stephen Ballou, a 56-year-old banker who got a nicotine vaccine in a 2007 clinical trial to help kick his pack-a-day habit. He says he hasn’t smoked since.
Some medications currently available to treat addictions typically work by mimicking a drug in the brain. For example, methadone stands in for heroin and the nicotine patch for cigarettes. Other medications block activity in the brain’s reward system. Alkermes Inc.’s once-monthly Vivitrol injection does this for alcoholics and opioid addicts, while Pfizer Inc.’s Chantix pills block the brain’s pleasure receptors activated when people smoke.
Small-molecule drugs like Chantix that function inside the brain can raise safety concerns. Chantix carries a federally mandated warning to users of possible depression and suicidal thoughts. A spokesman for Pfizer notes that no causal link between Chantix and such symptoms has been made.
By contrast, addiction-treatment vaccines work in the bloodstream, not the brain. Clinical trials have so far revealed no significant side effects, though the vaccines would do nothing to combat cravings. They work by tricking the body to reject drugs as if they are foreign pathogens. Normally, tiny drug molecules wend their way through the bloodstream to the brain, unleashing a flood of chemicals involved with pleasure and gratification. The drug molecules are too small to goad the immune system into generating antibodies to fight them off.
Scientists have figured out how to attach molecules similar to addictive drugs to much bigger antigens, such as deactivated versions of cholera or the common cold. When injected, these so-called conjugate vaccines spur the immune system to create antibodies to fight the tiny, addictive-drug molecules. These antibodies have in several studies glommed on to molecules of nicotine, cocaine and heroin ingested by lab animals and in some cases people, blocking them from triggering the pleasure centers in the brain.
Read the full article at the Wall Street Journal.