Monte Carlo simulations demonstrated that the trough concentrations of CLB and N-CLB in children with epilepsy could reach satisfactory target values under varying dose regimens in CYP2C19 NMs and IMs, whereas there was a failure to achieve the desired trough concentrations of CLB and N-CLB simultaneously in CYP2C19 PMs due to the accumulation of N-CLB. Here, CLYBL is linked to epilepsy.