ETHICAL IMPLICATIONS IN THE VACCINE PHARMACOTHERAPY TO TREAT AND PREVENT DRUG OF ABUSE DEPENDENCE

Different immunotherapeutic approaches are under development to the treatment of drug dependence. "Drug vaccines" aim to induce the immune system to produce antibodies that bind to drugs and prevent them from induce rewarding effects in the brain. The drugs of abuse currently being tested using this new approach are nicotine, cocaine, phencyclidine and methamphetamine. In laboratory animal models, a range of immunotherapy, including vaccines, monoclonal antibodies and catalytic antibodies, have reduced the drug seeking. In human clinical trials, "cocaine and nicotine vaccines" have been shown to induce sufficient antibody levels while producing few side effects. Studies in humans determining how these vaccines interact in combination with their target drug are underway. Nevertheless, although vaccines against drugs of abuse may become a viable treatment option, there are several drawbacks that need to be considered. These include a lack of protection against a structurally dissimilar drug that produces the same effects as the drug of choice; a lack of an effect on drug craving that predisposes an addict to relapse and a wide individual variability in antibody formation. Overall, immunotherapy offers a range of potential treatment options: drug treatment, as well as the treatment of overdose, prevention of brain or cardiac toxicity and fetal protection in pregnant drug abusers. Nevertheless the results obtained by a small-scale trials, using vaccines against cocaine and nicotine, suggest that a number of major technical challenges need to be overcome before that vaccines can be approved for clinical use.