Abstracts

VA Cooperative Study (VACS) #428 reported on treatment of 593 older individuals (average age 72, range 59-91) with newly diagnosed seizures who were assigned to one of three treatment groups: carbamazepine (CBZ), gabapentin (GBP) or lamotrigine (LTG -- Neurology 2005;64:1868-1873). The GBP and LTG groups demonstrated significantly better one year retention in study than CBZ (p=0.0001), due primarily to superior tolerability. There was little difference among the groups with respect to seizure control. We now consider whether there were age-related differences in our population with respect to seizure control and AED tolerability., We divided our population into three groups: ages 60-69, 70-79 and 80+. For each group we determined seizure-free rates at three, six and 12 months. Likewise, we determined retention in study at 12 months for the three groups. Finally, we considered the incidence of one of the study[apos]s principal side effects, sedation, for each age group., For the three age groups, the intent to treat (ITT) seizure free rate at 12 months showed a steady decline from the youngest to the oldest group for all three treatments.
The only exception was an improvement for GBP in the 70-79 group followed by a decline for the 80+ group. Overall, LTG was superior to the other two treatments. Breaking down the data into three, six and 12 month observations, we found that seizure free rate for GBP did not decline until after six months for the 60-69 group, whereas it declined steadily for the two older groups. For LTG, decline was arrested after six months for the 80+ group. For CBZ the only steady decline was in the 80+ group.
An important side effect, sedation, showed a steady increase in age-related incidence for the LTG and GBP groups. In particular, two-thirds (65.6%) of the GBP 80+ group reported sedation comapred with just over half that number (34.4%) for the 60-69 group. There was little change over the ages for CBZ., In elderly patients with newly diagnosed seizures, seizure control appears to decline with increasing age for all three treatments studied in VACS #428. Sedation shows an age-related increase for LTG and GBP, but little change for CBZ. The most profound increase in sedation occurred with GBP. Age considerations should play an important role in determining AED selection and usage in the elderly.[table1], (Supported by Department of Veterans Affairs.)