Carbamazepine blood levels are to monitor therapeutic effectiveness.

• A. Optional
• B. Not necessary
• C. Only if symptoms occur
• D. Required

Answer: (D)

Therapeutic drug monitoring is essential for anticonvulsants like carbamazepine because they have a narrow range where they work well and toxicity can be significant. The goal is to keep the drug level high enough to prevent seizures but low enough to avoid adverse effects. Carbamazepine also induces its own metabolism over time and interacts with other drugs, so levels can drift even with the same dose. By checking blood levels at steady state and after dose changes or symptoms, you can fine-tune the dose to maintain effectiveness and safety. That’s why monitoring is required rather than optional or only checking if symptoms appear.