Abstracts

Rationale: When added to cultured porcine ovarian cells, levetiracetam has been shown to increase basal testosterone secretion (1). We sought to determine whether levetiracetam use in male patients was associated with an increase in testosterone levels. Methods: Adult male patients who were started on levetiracetam for seizure prophylaxis were evaluated for total testosterone, free testosterone, sex hormone binding globulin (SHBG), luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels before and one month after leveticetam therapy. The Anger Attacks Scale was used to assess anger, irritability and frequency of anger outbursts before and after treatment. Results: Ten subjects were enrolled; results are available on five subjects thus far. Subjects ranged in age from 37 to 74 years, with a mean of 56. Total testosterone prior to starting levetiracetam ranged from 311 to 787 ng/dL with a mean of 518 ng/dL (SD 215). After levetiracetam therapy, total testosterone increased in 4 of 5 subjects and free testosterone increased in 3 of 5 subjects. The mean total testosterone after levetiracetam therapy increased to 592 ng/dL (SD 272) and the free testosterone increased from a mean of 63 pg/mL (SD 30) to a mean of 72 pg/mL (SD 37). SHBG decreased from a mean of 68 nmol/L (SD 41) to a mean of 56 nmol/L (SD 29). The changes in total testosterone and SHBG trended toward significance at p= 0.11 for each. No directional changes were present for LH or FSH. Subjects did not have seizures during the study and the Anger Attacks Questionnaire showed no directional change. Conclusions: These results suggest that although levetiracetam is not a hepatic enzyme inducer or inhibitor, it may increase testosterone levels by an as yet unknown mechanism, such as a direct gonadal effect. Larger studies are needed to confirm this preliminary finding. (1) Tauboll E, Gregoraszczuk EL, Tworzydo A, Wojtowicz AK, Ropstad E. Comparison of reproductive effects of levetiracetam and valproate studied in prepubertal porcine ovarian follicular cells. Epilepsia. 2006;47(9):1580-3. Supported by a grant from UCB.