Comment by cassowary37

Ironic that folks who work in CNS drug discovery spend much of their time worrying about how to get our molecules /into/ the brain... and less energy thinking about keeping non-CNS meds out. For what it's worth, though, these 'off-target' CNS effects have also prompted a lot of enthusiasm for repurposing existing FDA-approved drugs for new indications, since their safety is already established.