Diirected Drug Distribution: Adding Controlled Brain Activity to a Drug

Abstract
Environmental factors can alter the state of an organism so as to influence the response to drugs. This fact is widely recognized even though the responsible mechanisms are difficult to understand and control. The capacity of environmental influences to alter local drug pharmacokinetics is rarely considered. Drug localization and resulting action within the brain are influenced by vascular blood flow factors, local concentration ‘differences in competing neurohumours, and receptor density. These are all frequently asymmetrically represented in the brain and drug effects are correspondingly laterality dependent. Attention to regional brain pharmacokinetics and the influence of environment on regional blood flow, local neurohumor concentration, and receptor density represents an untapped opportunity to enhance the desired effect of a centrally active drug at its site of action without enhancing general systemic toxicity. Combined pharmacotherapy and psychotherapy may result in superior therapeutic responses. Psychotherapy is a potential tool deliberately to manipulate environmental factors that influence physiological and physical chemical parameters that determine drug disposition.