The carbamazepine test measures the level of carbamazepine in the blood. Carbamazepine is an anticonvulsant medication used to treat:

•  Epilepsy and seizure disorders 
•  Trigeminal neuralgia (nerve pain) 
•  Bipolar disorder (as a mood stabilizer) 

Monitoring blood levels ensures that the drug is within the therapeutic range—high enough to be effective but low enough to avoid toxicity.