SEATTLE—Patients taking enzyme-inducing antiepileptic drugs (AEDs) also take higher statin doses and have higher total cholesterol levels, compared with patients taking non–enzyme-inducing AEDs, reported Gina M. Jetter, MD, and colleagues at the 62nd Annual Meeting of the American Epilepsy Society.
The retrospective analysis included 137 patients (95% male) who attended an outpatient seizure clinic at the Audie L. Murphy VA Hospital in San Antonio, Texas. All subjects were taking at least one AED for epilepsy, as well as simvastatin for hyperlipidemia, for six months prior to examination of cholesterol levels. Patients who received valproate and other classes of cholesterol-lowering medications were excluded. The control group (n = 134) consisted of patients with epilepsy who were taking AEDs but not statins.
Adult Treatment Panel Guidelines for LDL Cholesterol Goal
“High levels of LDL cholesterol have shown to be a risk factor for coronary heart disease,” Dr. Jetter, Chief Resident in the Department of Neurology at the University of Texas Health Science Center in San Antonio, told Neurology Reviews. “Based on a patient’s risk factors for coronary heart disease (eg, comorbid hypertension, smoking, family history) an LDL cholesterol goal level is calculated. With the help of diet, exercise, and cholesterol-lowering medications—namely statins—a patient needs to be below his or her LDL cholesterol goal level to reduce the risk for coronary heart disease.”
According to the Adult Treatment Panel III guidelines, optimal LDL cholesterol levels for patients with coronary heart disease and coronary heart disease risk equivalents are less than 100 mg/dL. Patients with two or more major risk factors for coronary heart disease have an LDL cholesterol goal level of less than 130 mg/dL. Patients with one of these risk factors have an LDL cholesterol goal level of less than 160 mg/dL.
Enzyme-Inducing AEDs Increase Statin Dose, LDL Cholesterol Levels
Patients taking enzyme-inducing AEDs (n = 71) had a mean statin dose of 46.06 mg, compared with 36.52 mg for subjects on non–enzyme-inducing AEDS (n = 66). Patients were grouped according to simvastatin doses of 10 to 20, 40, and 80 mg daily. Unlike LDL and HDL cholesterol levels, the increase in total cholesterol levels was significant for the enzyme-inducing AED group (mean range, 165.2 to 169.7 mg/dL) versus the non–enzyme-inducing AED group (mean range, 161.4 to 151.6 mg/dL). Statins seemed less effective in patients taking enzyme-inducing AEDs, as their total cholesterol levels remained elevated. Those taking non–enzyme-inducing AEDs had lower total cholesterol levels. In addition, there were significant differences between non–enzyme-inducing AEDs and enzyme-inducing AEDs without statins (mean total cholesterol level, 177.9 vs 192.0 mg/dL; mean HDL cholesterol level, 44.3 vs 51.4 mg/dL; mean LDL cholesterol level, 109.1 vs 116.9 mg/dL). This suggests that enzyme-inducing AEDs may also affect cholesterol metabolism independent of statin use, observed the investigators.
“Patients taking enzyme-inducing AEDs need closer supervision of their cholesterol levels,” Dr. Jetter concluded. “If continually above cholesterol and LDL cholesterol goals despite statin treatment, physicians should consider switching their AED to a non–enzyme-inducing AED.
—Marguerite Spellman