How often and what type of control tests should be done during long-term anti-epileptic treatment?

During long-term epileptic treatment, it is essential to monitor the efficacy of the drugs used. Any adverse effects of this treatment must be detected early or preferably avoided. However, the type of control and the frequency with which this should be carried out are controversial. All anti-epileptic drugs are potentially liable to provoke adverse reactions of different types and degrees. Determinations of the blood-levels of anti-epileptic drugs are useful to attain optimus drug levels, and to identify any relationship there might be between these drugs and possible adverse effects. However, this usefulness varies, depending on the particular anti-epileptic drug concerned. Therefore measurement as a routine is not justified, but should be under taken to obtain the answer to specific questions. Laboratory analysis of blood to determine liver function, blood cell counts, coagulation, etc. is necessary in some cases. This may imply problems of interpretation and of cost. Is most cases it is of little help in the early detection or prevention of the most serious adverse reactions, which cause the greatest mortality. Therefore although such measures are necessary, attention should be paid to clinical methods for the early detection of symptoms and signs which may indicate the presence of adverse effects. Similarly, EEG should not be done as a routine for the assessment of the effect of treatment, but should be used when indicated for the follow-up of specific epileptic syndromes. An EEG may be useful for prognosis before suspending long-term epileptic treatment.