Pitch perception abnormality as a side effect of carbamazepine.

Carbamazepine (CBZ) is frequently used to treat patients with epilepsy, neuralgia, psychiatric diseases, etc. We prescribe it with care due to its side effects, mainly such as dizziness, sleepiness and cerebellar symptoms. But pitch perception abnormality is an uncommon side effect. We describe the case of a 12-year-old girl who exhibited half tone lowered pitch perception abnormality caused by CBZ. As CBZ acts as a central nervous system (CNS) inhibitor, we speculate that CBZ inhibits CNS and patients misperceive notes. We must prescribe CBZ with care to prevent pitch perception abnormalities.