It does not readily cross the blood--brain barrier of mammals due to the presence of P-glycoprotein, although crossing may still become significant if it is given at high doses (in which case, brain levels peak 2--5 hr after administration).
It does not readily cross the blood--brain barrier of mammals due to the presence of P-glycoprotein. Crossing may still become significant. It is given at high doses (in which case hr after administration). Case is brain levels peak 2--5.