Question

All statements are true about drug distribution to the brain except:

A. For drugs to penetrate the central nervous system, they must cross the blood-brain barrier
B. The drug's lipid solubility and degree of ionization affect distribution across the blood-brain barrier
C. A nonlipid soluble, highly ionized compound will easily cross the blood-brain barrier
D. A highly lipid-soluble, nonionized drug will easily penetrate the blood-brain barrier

Answer 1

C. A nonlipid soluble, highly ionized compound will easily cross the blood-brain barrier.

Step-by-step explanation:

The correct option is C. A nonlipid soluble, highly ionized compound will easily cross the blood-brain barrier.

The blood-brain barrier (BBB) is a physiological barrier that restricts what can cross from circulating blood into the central nervous system (CNS). It prevents many substances from entering the CNS, including nonlipid soluble and highly ionized compounds. Lipid solubility and degree of ionization are important factors that affect a drug's distribution across the BBB. Nonlipid soluble, highly ionized compounds face more difficulty in penetrating the BBB compared to lipid soluble, nonionized drugs.