Antidote to cocaine overdose developed

La Jolla - In what could be a major breakthrough in treating cocaine addiction, investigators at the Scripps Research Institute have developed an injectable solution that can protect mice from an otherwise lethal overdose of cocaine.

This discovery holds promise for future human clinical trials to treat cocaine overdoses. According to the Scripps Institute, cocaine is responsible for more than 400,000 emergency department visits each year. The Centers for Disease Control and Prevention (CDC) cited and about 5,100 deaths from cocaine overdose in the United States in 2008. Cocaine overdose may present as acute psychosis or paranoia, anxiety, agitation, aggressive behavior, sleeplessness, seizures, delirium, rapid heart rate, tremors or hallucinations. It can also cause deadly heart attacks or arrhythmia. Once it is developed for use in humans, this will be the first specific antidote to cocaine toxicity, according to lead author Kim Janada,Ph.D. director of The Worm Institute for Research and Medicine, at Scripps Research. According to study results, which were published in the March issue of the journal Molecular Pharmaceutics, this “passive vaccine” reversed the motor impairment, seizures and other dangerous symptoms of a cocaine overdose. The study authors described this vaccine as a composition of pre-formed human antibodies against cocaine that are 10 times more potent in binding cocaine molecules than an active vaccine. This improved potency speeds up their ability to reverse cocaine toxicity, when time is of the essence. The new cocaine vaccine works similarly to snakebite anti-venom. When injected, cocaine-specific antibodies swiftly removed cocaine molecules from the bloodstream, immediately limiting the drug’s direct impact on the heart and other vital organs. Importantly, researchers found that this process lowered the bloodstream concentration, allowing cocaine molecules - which are small enough to cross the blood-brain barrier - to rapidly diffuse out of brain tissue and potentially limit its damage. In active vaccines, antibodies bind to circulating cocaine molecules in the blood and prevent these drug molecules from reaching the brain, making the user feel no pleasurable effects. However, it can take weeks to build up enough antibodies to be effective. Dr. Janada and his colleagues have also been working on antidotes for other powerful and potentially lethal drugs like heroin, nicotine and the so-called date rape drug Rohypnol, but they are all been active vaccines. Dr. Janda and research associate Jennifer Treweek, PhD. are working on methods to economically produce large quantities of the antidote so clinical trials can begin. This vaccine also has potential to help prevent relapses immediately following crisis episodes, In a statement published by Scripps Research, Dr. Janada said “a lot of people that overdose end up going back to the drug rather quickly, but this antibody would stay in their circulation for a few weeks at least, and during that time the drug wouldn't have an effect on them."