CYP2D6 expression in the whole blood of epileptic patients in treatment with Carbamazepine

Carbamazepine (CBZ) is a commonly prescribed drug for patients with epilepsy. However, after administration of CBZ, many patients experience cutaneous adverse drug reactions (CADRs), the most common allergic skin symptoms. CYP2D6 enzyme is one of the enzymes that play an important role in drug metabolism in general and CBZ in particular. Therefore, analysis of gene expression and enzyme activity of CYP2D6will help predict the magnitude of CBZ metabolism of the patients, allowing them to forecast CADRs. In this study, the authors evaluated the mRNA expression of CYP2D6 in CBZ-treated epilepsy patients using a Real-time PCR method, and then investigated the relationship of CYP2D6 expression levels between mild and severe CADR harbouring groups. The results showed that the expression level of CYP2D6 in the CBZ-tolerant group was about 3 times higher than that in the CBZ-allergic group. These results suggested that the gene expression level of CYP2D6 could be a useful biomarker for predicting CBZ response in patients with epilepsy.