True or False: Some drugs may be excreted in breast milk.

True or False: Some drugs may be excreted in breast milk.

• A. False
• B. Only in men
• C. Only with topical administration
• D. True

Answer: (D)

Some drugs can pass from a nursing mother’s bloodstream into breast milk, so they can be excreted into milk. This happens because drugs reach milk by diffusion and the amount depends on factors like how lipid-soluble the drug is, its molecular size, how tightly it binds to plasma proteins, and the mother’s plasma concentration. The milk is slightly acidic, which can also cause certain drugs—especially basic ones—to become ionized in milk and remain there longer, increasing infant exposure. Because of these principles, it is possible for drugs to be present in breast milk, making the statement true. The other options don’t fit: no drugs being excreted in breast milk is false, since there is documented transfer; restricting this to men or to topical administration ignores the fact that any systemic exposure can lead to milk excretion, and topical use can still result in systemic absorption in some cases.

Some drugs can pass from a nursing mother’s bloodstream into breast milk, so they can be excreted into milk. This happens because drugs reach milk by diffusion and the amount depends on factors like how lipid-soluble the drug is, its molecular size, how tightly it binds to plasma proteins, and the mother’s plasma concentration. The milk is slightly acidic, which can also cause certain drugs—especially basic ones—to become ionized in milk and remain there longer, increasing infant exposure. Because of these principles, it is possible for drugs to be present in breast milk, making the statement true.

The other options don’t fit: no drugs being excreted in breast milk is false, since there is documented transfer; restricting this to men or to topical administration ignores the fact that any systemic exposure can lead to milk excretion, and topical use can still result in systemic absorption in some cases.