Utilization and Costs of Antiepileptic Drugs in the Elderly

The aging of the general population in industrialized countries has brought to public attention the increasing incidence of age- and aging-related clinical conditions. Management of multiple and chronic disorders has become a more important issue for healthcare authorities because of increasing requests for medical assistance, the greater numbers of drugs required and drug interactions reported, and the increase in treatment-related costs.

Epilepsy is a chronic clinical condition affecting both sexes and all ages with a worldwide distribution. The incidence of epilepsy, after childhood, increases with age and the cumulative risk of epilepsy by 80 years of age ranges from 1.3% to 4% in different study populations. Although the issues for people with epilepsy are similar for older and younger adults, the elderly may require more attention with regard to selection of antiepileptic drugs (AEDs) than younger patients. Elderly patients with newly diagnosed epilepsy are more likely to remain seizure-free on AED therapy than younger populations; however, the toxicity of AEDs in elderly patients is ill-defined because seizures may be difficult to recognize in this group and the symptoms and signs of toxicity can be attributed to other causes. Moreover, elderly people have chronic clinical conditions and are more likely to be taking medications that could possibly interfere with AEDs.

Some older AEDs such as phenobarbital and phenytoin should not be used in the elderly because of their pharmacokinetic and pharmacodynamic profiles. There is no evidence that new AEDs, despite their better tolerability profiles, are advantageous in terms of attaining freedom from seizures compared with older agents.

Older AEDs are much less expensive than the new compounds and, with some exceptions, appear to be more cost effective. New AEDs may be cost effective only in patients who are not able to tolerate or who are resistant to older compounds or when the use of an older drug is contraindicated. However, there are no cost-effectiveness studies in the elderly and further evidence is needed to confirm these assumptions.