Which statement about drug interactions is true?

• A. It induces hepatic metabolism, lowering other drugs' levels.
• B. It inhibits hepatic metabolism increasing other drugs' levels.
• C. It has no interactions.
• D. It prevents absorption of all other drugs.

Answer: (A)

The main concept is that some drugs can change how quickly other drugs are processed by the liver. When a drug acts as an inducer of hepatic enzymes, it boosts the liver’s metabolic activity. This speeds up the breakdown of other medications, so their blood levels fall and their effects can be reduced. Because enzyme induction takes time to develop, this effect usually appears after several days and can last for a while after the inducer is stopped—until enzyme levels return to baseline.

This makes the statement about inducing hepatic metabolism lowering other drugs’ levels true. The idea that a drug only inhibits metabolism and raises levels describes a different, but real, mechanism (inhibitors). Saying there are no interactions or that a drug universally prevents absorption of all others are incorrect.