What outcome is associated with pregnancy-related enzyme induction regarding drug levels?

• A. Subtherapeutic concentrations due to increased metabolism
• B. Increased peak concentrations due to slower metabolism
• C. No change in drug levels
• D. Delayed elimination leading to toxicity

Answer: (A)

During pregnancy, hormonal changes can induce hepatic enzymes, speeding up the metabolism of many drugs. This increased metabolism clears the drug from the body more quickly, leading to lower plasma concentrations. If dosing isn’t adjusted, those levels can fall below the therapeutic range, producing subtherapeutic effects.

This is why subtherapeutic concentrations due to increased metabolism is the best description. Increased peak concentrations would occur if metabolism were slower, no change in levels would ignore the induction effect, and delayed elimination leading to toxicity would imply slower clearance rather than the faster clearance seen with enzyme induction.