If a drug was present in the bloodstream but unable to cross the blood-brain barrier,then one could conclude:
A) that nonspecific binding occurred.
B) the drug could enter the brain using active transport mechanisms.
C) the drug's pKa had matched the pH of the physiological medium it was administered in.
D) the drug was not small, non-charged or lipid soluble.

Question

Quizplus · Accepted Answer

The blood-brain barrier only allows small, non-charged, lipid-soluble molecules to pass through. If a drug is unable to cross the blood-brain barrier, it is likely because it does not meet these requirements.

If a Drug Was Present in the Bloodstream but Unable