Evaluation of the anticocaine monoclonal antibody GNC92H2 as an immunotherapy for cocaine overdose.

The illicit use of cocaine continues in epidemic proportions and treatment for cocaine overdose remains elusive. Current protein-based technology offers a new therapeutic venue by which antibodies bind the drug in the blood stream, inactivating its toxic effects. The therapeutic potential of the anticocaine antibody GNC92H2 was examined using a model of cocaine overdose. Swiss albino mice prepared with intrajugular catheters were tested in photocell cages after administration of 93 mg/kg (LD50) of cocaine and GNC92H2 infusions ranging from 30 to 190 mg/kg. GNC92H2 was delivered 30 min before, concomitantly or 3 min after cocaine treatment. Significant blockade of cocaine toxicity was observed with the higher dose of GNC92H2 (190 mg/kg), where premorbid behaviors were reduced up to 40%, seizures up to 77% and death by 72%. Importantly, GNC92H2 prevented death even post-cocaine injection. The results support the important potential of GNC92H2 as a therapeutic tool against cocaine overdose.

Cannabinoid receptor antagonist reduces heroin self-administration only in dependent rats.

Functionality of the endogenous cannabinoid system undergoes relevant changes in reward-related brain areas in animal models of opiate addiction. By using a limited access heroin self-administration paradigm we show that cannabinoid CB(1) receptor antagonist N-(piperidin-1-yl)-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide hydrochloride (SR141716A, 0.03-3.0 mg/kg) suppresses heroin self-administration only in opiate-dependent rats but not in non-dependent animals. These results further support the study of cannabinoid CB(1) receptor antagonists for the treatment of opiate addiction.

Cocaine pharmacology and current pharmacotherapies for its abuse.

Cocaine abuse continues to be prevalent and effective therapies for cocaine craving and addiction remain elusive. In the last decade immunopharmacotherapy has been proposed as a promising means to alleviate this illness. By using the organism's natural immune response, an anti-cocaine vaccine promotes the production of cocaine-specific antibodies that sequester the drug before their passage into the brain, where it exerts its reinforcing and thus addictive effects. A series of studies demonstrating the cocaine-blocking properties of various immunogenic conjugates will be reviewed in the context of the neuropsychopharmacological profile of the drug.

Treating cocaine addiction with viruses.

Cocaine addiction continues to be a major health and social problem in the United States and other countries. Currently used pharmacological agents for treating cocaine abuse have proved inadequate, leaving few treatment options. An alternative is to use protein-based therapeutics that can eliminate the load of cocaine, thereby attenuating its effects. This approach is especially attractive because the therapeutic agents exert no pharmacodynamic action of their own and therefore have little potential for side effects. The effectiveness of these agents, however, is limited by their inability to act directly within the CNS. Bacteriophage have the capacity to penetrate the CNS when administered intranasally. Here, a method is presented for engineering filamentous bacteriophage to display cocaine-binding proteins on its surface that sequester cocaine in the brain. These antibody-displaying constructs were examined by using a locomotor activity rodent model to assess the ability of the phage-displayed proteins to block the psychoactive effects of cocaine. Results presented demonstrate a strategy in the continuing efforts to find effective treatments for cocaine addiction and suggest the application of this protein-based treatment for other drug abuse syndromes.

Investigations using immunization to attenuate the psychoactive effects of nicotine.

Despite the enormous health risks, people continue to smoke and use tobacco primarily as a result of nicotine addiction. As part of our immunopharmacotherapy research, the effects of active and passive immunizations on acute nicotine-induced locomotor activity in rats were investigated. To this end, rats were immunized with either a NIC-KLH immunoconjugate vaccine designed to elicit an antinicotine immune response, or were administered an antinicotine monoclonal antibody, NIC9D9, prior to a series of nicotine challenges and testing sessions. Vaccinated rats showed a 45% decrease in locomotor activity compared to a 16% decrease in controls. Passive immunization with NIC9D9 resulted in a 66.9% decrease in locomotor activity versus a 3.4% decrease in controls. Consistent with the behavioral data, much less nicotine was found in the brains of immunized rats. The results support the potential clinical value of immunopharmacotherapy for nicotine addiction in the context of tobacco cessation programs.