Therapeutic Drug Monitoring of Antiepileptic Drugs in Turkey: Five Years’ Experiences

Öz

Therapeutic drug monitoring (TDM) plays a major role in planning and optimizing the treatment of a patient, as in the treatment of epilepsy. The monitoring of antiepileptic drugs (AEDs) in the management of epilepsy is crucial because of their complex pharmacokinetic properties, narrow therapeutic index, and wide fluctuations. In this study, we aimed to investigate the 5-year TDM results of AED, which is one of the most applied groups to our laboratory, in terms of age, gender and plasma concentrations (by therapeutic limit). We also aimed to guide clinicians who diagnose and treat epilepsy patients. This study was conducted to retrospectively analyze the TDM results of patients in Eskişehir Osmangazi University Hospital between 2013-2018. The AED levels were classified as below, within, and above the reference range. The monitored drugs were valproic acid, carbamazepine, phenytoin, phenobarbital, and levetiracetam. The percent of all drug level results analyzed for valproic acid, carbamazepine, levetiracetam and phenobarbital was within the reference range. Phenytoin showed wide fluctuation and its subtherapeutic level was notably high. In practice, TDM was found to be helpful in the of adjustment drug dosage with regard to the response of individual patients.

Anahtar Kelimeler

• serum drug levels
• antiepileptics
• therapeutic drug monitoring

Türkiye’de Antiepileptik İlaçların Terapötik İlaç Düzeyi İzlemi: Beş Yıllık Deneyim

Öz

Terapötik ilaç düzeyi izlemi (TİDİ), epilepsi tedavisinde olduğu gibi bir hastanın tedavisinin planlanmasında ve optimize edilmesinde önemli bir rol oynamaktadır. Epilepsi tedavisinde antiepileptik ilaçların (AEİ) düzeyinin izlenmesi, karmaşık farmakokinetik özellikleri, dar terapötik indeksleri ve geniş fluktuasyonları nedeniyle çok önemlidir. Bu çalışmada laboratuvarımızda en çok uygulanan gruplardan biri olan AEİ'nin 5 yıllık TİDİ sonuçlarını yaş, cinsiyet ve plazma konsantrasyonları açısından (terapötik limtlerine göre) araştırmayı amaçladık. Ayrıca epilepsi hastalarını teşhis ve tedavi eden klinisyenlere rehberlik etmeyi amaçladık. Bu çalışma 2013-2018 yılları arasında Eskişehir Osmangazi Üniversitesi Hastanesi'ndeki hastaların TİDİ sonuçlarını retrospektif olarak analiz etmek için yapıldı. AEİ seviyeleri referans aralığı altında, referans aralığı içinde ve üstünde olarak sınıflandırıldı. İzlenen ilaçlar valproik asit, karbamazepin, fenitoin, fenobarbital ve levetirasetam’dı. Valproik asit, karbamazepin, levetirasetam ve fenobarbital için analiz edilen tüm ilaç seviyesi sonuçları yüzdeleri referans aralığındaydı. Fenitoin geniş fluktuasyon gösterdi ve terapötik düzeyi oldukça yüksekti. Uygulamada, TİDİ'nin, bireysel hastaların cevabında ayarlama yapılmasının ilacın dozajında yardımcı olduğu bulunmuştur.

Anahtar Kelimeler

• serum ilaç düzeyi
• antiepileptikler
• terapötik ilaç düzeyi izlemi

Kaynakça

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