The penetration of anti-infectives into the central nervous system

The blood-brain barrier, blood-cerebrospinal fluid (CSF) barrier, and menin ges are a complex and difficult-to-study system charged with protecting the central nervous system (CNS) from toxins, including drugs. Current estimat es of CNS drug exposure are limited to CSF to blood ratios, of which area-u nder-the curve (AUC) estimates provide the most robust measure of drug expo sure. Different classes of drugs and individual drugs within classes have d ifferent CNS penetration potential that is dependent upon a variety of biol ogic and pharmacologic factors. Clinical data (AUC and point ratios) regard ing the penetration of several anti-infective agents used for the treatment of CNS infections are provided in this article.