Carbamazepine induces which enzyme that is NOT listed among those induced?

Carbamazepine induces which enzyme that is NOT listed among those induced?

• A. CYP3A4
• B. CYP1A2
• C. CYP2D6
• D. CYP2C9

Answer: (D)

Carbamazepine acts as a strong inducer of hepatic cytochrome P450 enzymes, boosting the body’s production of certain drug‑metabolizing enzymes. The most clinically relevant enzymes it increases are CYP3A4, CYP1A2, and CYP2C9 (with some induction also seen in CYP2C19). This means drugs that are substrates for these enzymes are cleared faster when a patient is taking carbamazepine, which can lower their effectiveness and may require dose adjustments. Carbamazepine also shows autoinduction, meaning it can increase its own metabolism over time. Among the enzymes listed, carbamazepine does not meaningfully induce CYP2D6. Therefore, the enzyme that is not induced by carbamazepine is CYP2D6. This distinction helps predict interactions: drugs reliant on CYP3A4, CYP1A2, or CYP2C9 may be cleared more quickly with carbamazepine, whereas drugs primarily metabolized by CYP2D6 would not experience the same induction effect.

Carbamazepine acts as a strong inducer of hepatic cytochrome P450 enzymes, boosting the body’s production of certain drug‑metabolizing enzymes. The most clinically relevant enzymes it increases are CYP3A4, CYP1A2, and CYP2C9 (with some induction also seen in CYP2C19). This means drugs that are substrates for these enzymes are cleared faster when a patient is taking carbamazepine, which can lower their effectiveness and may require dose adjustments. Carbamazepine also shows autoinduction, meaning it can increase its own metabolism over time.

Among the enzymes listed, carbamazepine does not meaningfully induce CYP2D6. Therefore, the enzyme that is not induced by carbamazepine is CYP2D6. This distinction helps predict interactions: drugs reliant on CYP3A4, CYP1A2, or CYP2C9 may be cleared more quickly with carbamazepine, whereas drugs primarily metabolized by CYP2D6 would not experience the same induction effect.