بررسي غلظتهاي سرمي داروهاي ضد صرع در بيماران مقاوم به درمان دارويي

Study of Serum Levels of Anticonvulsant Drugs in Patients with Refractory Epilepsy Undergoing Treatment in Imam Khomeini and Razi Hospitalsʹ Tabriz

Background and Objectives: Although many studies have been carried out on therapeutic drug monitoring (TDM) of anticonvulsant drugs, there are few reports on TDM of these drugs in patients with refractory epilepsy. In this study, serum levels of carbamazepine, Phenobarbital and phenytoin in epileptic patients and patients with refractory epilepsy, are investigated. Furthermore, in this study the efficiency of clinical-based drug treatment protocols designed and used by the physicians to treat patients with refractory epilepsy in Imam Khomeini and Razi Hospitals of Tabriz, is evaluated. Materials and Methods: The subjects of this study were 66 epileptic patients undergoing treatment in Imam Khomeini and Razi Hospitals of Tabriz, of which 29 suffered from refractory epilepsy. About 0.5 mL serum was obtained from each patient and the concentrations of drugs were determined using HPLC method. Results: No significant difference was observed in the serum levels of drugs and average doses of phenobarbital and phenytoin in both groups (p>0.05). However, the average dose of carbamazepine in patients with refractory epilepsy, was higher than that of other group. The absence of significant differences in the serum levels of carbamazepine in both groups, in spite of using higher average doses in patients with refractory epilepsy, could be indicative of the presence of differences in pharmacokinetics of this drug in both groups. The serum levels of carbamazepine and phenobarbital, were slightly higher than the lowest limit of reported therapeutic range of drugs; however, the corresponding value for phenytoin was even lower than the lowest limit of the reported therapeutic range for this drug. Conclusion: The results were indicative of necessity for renewing the treatment protocols used in Imam Khomeini and Razi Hospitals for patients with refractory epilepsy. There were also evidences indicating a difference in the pharmacokinetics of carbamazepine in patients with refractory epilepsy.