Once they have been metabolized by the liver, the metabolites may be:
1. More active than the parent drug
2. Less active than the parent drug
3. Totally deactivated so they are excreted without any effect
4. All of the above
Question 2
Which of the following statements about the major distribution barriers (blood-brain or fetal-placental) is true?
1. Water soluble and ionized drugs cross these barriers rapidly.
2. The blood-brain barrier slows the entry of many drugs into and from brain cells.
3. The fetal-placental barrier protects the fetus from drugs taken by the mother.
4. Lipid-soluble drugs do not pass these barriers and are safe for pregnant women.