Therapeutic drug monitoring of antiepileptic drugs: current status and future prospects

ABSTRACT

Introduction: Antiepileptic drugs (AEDs) are the cornerstone of treatment of patients with epilepsy, and there are presently 27 licensed AEDs making AEDs among the most common medications for which therapeutic drug monitoring (TDM) is performed. The aim of this review is to provide an overview of the current evidence of the use and implementation of AED TDM in patients with epilepsy and other non-epilepsy conditions.

Areas covered: The pharmacokinetic variability of AEDs is extensive, resulting in pronounced variability in serum concentrations between patients. TDM may thus be useful to individualize the treatment of patients with epilepsy and also in non-epilepsy conditions. Indications for TDM include settings where pharmacokinetic variability is anticipated (e.g. in children, the elderly, during pregnancy, and patients prescribed polytherapy resulting in drug interactions) and drug adherence. TDM contributes to provide a quality assurance of the treatment. Patient management is, therefore, best guided by the determination of individual therapeutic concentrations.

Expert opinion: Because of pharmacokinetic variability is prevalent among AEDs, TDM allows a bespoke approach to epilepsy care allowing dose adjustments based on measured drug concentrations so as to optimize clinical outcome. Future advances include the use of additional markers of toxicity and genetic variability so as to further aid individualization and optimize AED treatment.

KEYWORDS:

• Antiepileptic drugs
• epilepsy
• drug interactions
• pharmacokinetic variability
• therapeutic drug monitoring

Article highlights

• The pharmacokinetic variability of all AEDs is extensive, resulting in pronounced variability in serum concentrations between patients, and may be challenging in special patient groups such as children, pregnant women, and the elderly

• Therapeutic drug monitoring (TDM) contributes to quality assurance of the treatment, taking pharmacokinetic variability, drug interactions, adherence, and other treatment challenges into account

• Future advances for TDM of AEDs include use of additional markers of toxicity and genetic variability to individualize and optimize treatment

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Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This paper was not funded.