Lamotrigine plasma levels reduced by oral contraceptives

Although it is known that the use of oral contraceptives (OC's) can induce glucuronide conjugating enzymes, currently no data exists as to the potenti al that the elimination of the glucuronidated drug lamotrigine (LTG) is inc reased by OC's. We present seven cases in whom the plasma levels of LTG wer e significantly decreased by OC's (mean 49% range 41-64%). The interaction was of clinical relevance in most of the patients who either experienced in creased seizure frequency/recurrence of seizures after OC's had been added. or adverse effects following withdrawal of OC's. (C) 2001 Elsevier Science B.V. All rights reserved.