Abstracts

In abstracts from the annual AES meeting Dec 2004 (VOL 45 supp7), we observed an article concerning lamotrigine (LTG) and increasing serum creatinine levels (p. 139). The Physicians[apos] Desk Reference (PDR) lists increased serum creatinine as a rare (occuring in less than 1/1000 patients) adverse event. We investigated the frequency and extent of this possible phenomenon in a randomly chosen group of our LTG treated patients. We retrospectively analyzed the data of our patients who have been treated with LTG for at least one year. The relationship between LTG and serum creatinine was investigated. We randomly chose 117 patients on LTG. 35 patients were excluded from this study because no baseline creatinine was available or the patients had been on LTG for less than 1 year. 82 patients with a mean age of 37.4 years, 34 (41.4%) males and 48 females (58.6%) were eligible for our study. In these 82 patients treated for an average of 3.6 years, the mean change in serum creatinine was 0.03 mg/dL. In 43(52.4%) patients on LTG for an average of 36 months, the serum creatinine increased by an average of 0.15mg/dL. In 20 patients (24%) on LTG for an average of 65 months, the serum creatinine decreased by an average of 0.l8mg/dL. In 19 patients (23.1%) on LTG for an average of 38 months, the serum creatinine did not change. The serum creatinine remained within the normal range (0.5 - 1.4 mg/dL) despite these changes. LTG treatment did not significantly impact creatinine levels. In our review of 82 patients, lamotrigine did not cause any clinically significant increase in serum creatinine nor was there any apparent impairment in renal function. This does not preclude the possibility of rare occurence of this phenomenon. (Supported by The Comprehensive Epilepsy Care Center for Children and Adults.)