antiepileptics and microsampling: TDM for AEDs is easy as ABC

Therapeutic drug monitoring (TDM) is essential for those taking medication for the long run, such as those who use anti-epileptic drugs (AEDs). For AED monitoring, the most common method uses a liquid chromatography that is of high performance to determine the presence of anti-epileptic drugs in the human plasma. Some of the most common anti-epileptic drugs monitored through therapeutic drug monitoring include the following.

• Lamotrigine
• Oxcarbazepine
• Tiagabine
• Rufinamide
• Levetiracetam
• Zonisamide

Anti-Epileptic Therapeutic Drug Monitoring

The primary goal of AED therapeutic drug monitoring is the optimization of a patient’s clinical outcome by supporting management of the patient’s medication through measurement of drug concentration levels. Therapeutic drug monitoring has become very important in treatment with the AEDs since it can be quite difficult to identify a patient’s optimal dose on just the clinical basis. This is due to a number of reasons. Some of the reasons include:

• Clinical symptoms of toxicity are not readily detectable.
• There are no direct laboratory indicators for AED toxicity or clinical efficacy.
• The interconnection between AED serum levels and clinical effects is much better compared to that of dose and effect.
• AED treatment is purely prophylactic, and since seizures occur at irregular intervals it is hard to determine whether a prescription will be sufficient to control seizures long term.

The process of monitoring requires samples of blood from the patient and for the longest time, venipuncture has been the main technique used to obtain blood. However, this method has proven to be an invasive technique. Technological advancement has facilitated the invention of new techniques that are less invasive and allow drawing little amounts of blood compared to venipuncture.

One of these technologies is microsampling. It allows drawing very little amounts of blood (as little as 10 µL to 20 µL) which can be used for the therapeutic drug monitoring (TDM). With the amount of blood needed for these tests from time to time, it is the safest method of obtaining blood from patients without having to put the patients’ health in jeopardy. Other than that remote patient monitoring with microsampling, is an easy and convenient method of blood sample collection and can be done even in remote areas where patients can draw blood on their own and send the sample to the lab for evaluation. With microsampling, TDM for AEDs is as easy as ABC.