BOSTON—Prescribing patterns for antiepileptic drugs (AEDs) for older patients who have been newly diagnosed with epilepsy do not match the current clinical recommendations, according to a report at the 57th Annual Meeting of the American Epilepsy Society. Recent recommendations for the treatment of elderly patients newly diagnosed with epilepsy include as first-line therapy AEDs such as carbamazepine, lamotrigine, gabapentin, or oxcarbazepine, as opposed to older drugs with more adverse effects in the elderly, such as phenobarbital and phenytoin, according to Mary Jo V. Pugh, PhD, RN.

Dr. Pugh and colleagues from the Center for Health Quality at ENRM Veterans Hospital in Bedford, Massachusetts, examined national inpatient, outpatient, and pharmacy data from the Veterans Administration (VA) to identify veterans 65 and older who had been diagnosed with epilepsy in 1999 and who had received AEDs from the VA. The patients’ drug regimens were classified, and the investigators used these data to determine whether clinical practice was consistent with recommendations and who was at the greatest risk of receiving potentially problematic AEDs.

STATISTICAL ANOMALY

According to the investigators’ findings, 85% of patients received monotherapy. Of these, 4.67% received phenobarbital monotherapy, 69% received phenytoin monotherapy, and 26.53% received monotherapy consisting of one of the “recommended AEDs.” Of the remaining patients receiving combination therapy, 29.27% received combinations including phenobarbital, 53.31% including phenytoin, and 17.42% received a combination of the recommended AEDs, Dr. Pugh noted.

Additional analyses revealed that patients with more severe disease were less likely to receive phenobarbital monotherapy than other monotherapy (odds ratio [OR], 0.47); they were also less likely to receive phenobarbital combinations than other combinations (OR, 0.29). Patients who consulted a neurologist were less likely to receive phenytoin monotherapy than one of the recommended monotherapies (OR, 0.49), and whites were less likely to receive phenytoin monotherapy than recommended monotherapy (OR, 0.54), the researchers reported.

PROBLEM PRESCRIPTION

“A surprising number of newly diagnosed veterans received phenobarbital despite its well-known adverse effects,” said Dr. Pugh. She also noted that the group’s finding that “nearly 70% receive phenytoin is not consistent with recent recommendations for epilepsy care in the elderly.”

Their findings “suggest that a reevaluation of treatment patterns for older patients with epilepsy is necessary,” and that this problem may be even more pronounced in the public sector, where cost may be an important predictor of what is prescribed for older patients with limited income, she added. With 1.5% of older Americans actively being treated for epilepsy—a rate that data suggest will increase—there is specifically a call for research to investigate why drugs that have been considered suboptimal treatments for epilepsy in the elderly for many years (in the case of phenobarbital, more than 15 years) are still being prescribed to newly diagnosed patients, Dr. Pugh said.

Other points of possible clinical relevance raised by the study that remain to be pursued include “the differential relationship of disease severity to use of phenytoin and phenobarbital” and the findings of treatment variation by race, the investigators noted. Finally, further research evaluating the effectiveness of phenytoin and other AEDs on the elderly in clinical practice “is necessary to provide clinicians with additional evidence on which to base prescribing decisions,” the investigators said.

NR

—C. Justin Romano

Suggested Reading
Palmieri C, Canger R. Teratogenic potential of the newer antiepileptic drugs: what is known and how should this influence prescribing? CNS Drugs. 2002;16:755-764.
Perucca E. Current trends in antiepileptic drug therapy. Epilepsia. 2003;44 Suppl 4:41-47.
Pugh MJ, Cramer JA, Knoefel J, et al. Potentially inappropriate drugs for elderly patients with epilepsy. J Am Geriatr Soc. 2004. In press.

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