Abstracts

Incidence of new onset partial epilepsy is highest in elderly patients. Choice of anti-epileptic drug (AED) is limited due to multiple comorbidities, concomitant medications and scarce published clinical experience in this population, especially after an AED failure. Sodium divalproex (SDV) was chosen as alternative monotherapy, because it was available and approved for the intended use in our patients. Medical charts of 13 male patients taking SDV monotherapy after failure (lack of efficacy n=2, toxicity n=11) of gabapentin, lamotrigine, or carbamazepine monotherapy were reviewed after obtaining IRB exemption of informed consent. Data regarding seizure frequency, side effects, comorbidities, hematology, chemistry, serum SDV levels, and demographics were collected from each visit note and compared longitudinally for each patient. SDV starting dose was 250mg b.i.d. with weekly increments of 250mg per day to reach a target maintenance dose of 500mg b.i.d. Dose adjustments were performed to achieve or maintain seizure freedom, or minimize side effects. Age at onset and duration of SDV treatment averaged 74 years (62-86 years) and 13.9 months (0.2-28.0 months), respectively. SDV maintenance doses were 250mg b.i.d. (n=4), 500mg b.i.d (n=7), 500mg t.i.d. (n=1), and 750mg b.i.d (n=1). Serum SDV levels averaged 51.8 microgram/ml (n=5), 55.0 microgram/ml (n=6), and 63.5 microgram/ml (n=7) at 3, 6, and 12 months, respectively. Comedications averaged 9 (2-16) per patient; the most common 5 were acetyl-salycilic acid (n=9), albuterol (n=5), lisinopril (n=5), furosemide (n=4), and KCl (n=4). Seizure types included simple partial seizures only (n=5), complex partial seizures (CPS) only (n=3), secondarily generalized seizures (2GTC) only (n=4) and CPS with 2GTC (n=1). Nine patients continued to be seizure free from the first AED monotherapy, and four became seizure free at 6 months after starting SDV. Three patients discontinued within the first 3 months: due to rash (n=1); myoclonic jerks, tremor, and unsteady gait with fear of falling (n=1); and dizziness, tremor and impotence (n=1). Of the remaining 10 patients only 2 reported side effects; namely, tremor of moderate severity. No clinically important changes in platelet count or liver function tests were observed. Four patients reported weight gain and three reported weight loss of [gt]5 pounds. Patients[apos] average weight was 192 pounds at the last visit. SDV monotherapy was efficacious and well tolerated in the majority of our study population of elderly patients with new onset seizures. The use of SDV as first or second choice in elderly patients with new onset partial epilepsy is a reasonable option. (Supported by Malcom Randall VA Medical Center and the University of Florida, Gainesville, Florida)