Drug Entry Into the Brain and Its Pharmacologic Manipulation

Abstract

During recent years much progress has been made in pharmacology which has resulted in the introduction of several important new drugs into clinical medicine. Even greater progress has been made in the arena of biopharmaceutical technology, with the development of a number of peptides and genetically engineered agents which interact, with high specificity, with intra- and/or extracellular targets at a molecular level. It is probable that many of these new peptide and protein therapeutics will undergo clinical assessment during this decade. For the vast majority of drugs, peptides, and proteins the relation between dose and effect is critical. Most therapeutic agents produce their required pharmacologic response by interfering with some specific aspect of cell function or structure in a concentration-dependent and reversible manner. To obtain a required pharmacologic response, the administration, absorption, and transport of a threshold amount of drug to the target is essential. Further, this often must occur at the correct time for a pharmacologic effect to be elicited and maintenance of drug at the target may be required for a specific time to achieve a clinically valuable response. Thus, for an optimal pharmacologic response, control of drug input and time-dependent knowledge of drug disappearance, due to distribution, metabolism, and excretion processes, is required.