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 potential that the elimination of the glucuronidated drug lamotrigine (LTG) is increased by OC's. We present seven cases in whom the plasma levels of LTG were significantly decreased by OC's (mean 49%, range 41-64%). The interaction was of clinical relevance in most of the patients who either experienced increased seizure frequency/recurrence of seizures after OC's had been added, or adverse effects following withdrawal of OC's.

Clinical experiences with topiramate in children with intractable epilepsy.

At a tertial referral epilepsy centre 39 children were consecutively enrolled in an open add-on study with topiramate (TPM). All children had intractable epilepsy; the mean seizure frequency was 36 per month, and 31 children were treated with polypharmacy. All but five children were mentally retarded. The initial dose of TPM was 0.5-1 mg/kg daily, slowly titrated with 1-3 mg/kg daily every second week with an estimated target dose of 10 mg/kg daily. At latest follow-up 19 children continued on TPM, three (8%) were seizure-free, eight (21%) had a seizure reduction of more than 50% and eight (21%) improved their general condition. Mean follow-up was 13 months (range 9-36 months). Seizure reduction was seen in focal as well as generalized epilepsies. Adverse effects were reported in 21 cases (54%), weight loss and sedation being most frequent. The mean steady state dose in the children continuing on TPM was at latest follow-up: 14 mg/kg daily (< 5 years), 10 mg/kg daily (5-7 years), 5.8 mg/kg daily (8-17 years). The corresponding plasma level varied from 3 to 45 mumol/litre, and a significant correlation between the daily dose in mg/kg and the plasma level was found. Two patients with progressive myoclonus epilepsy are described separately; one had a dramatic general improvement. It is concluded that TPM seems to be a promising new broad-spectrum anti-epileptic drug, which is efficacious even in epilepsy syndromes, intractable to other new anti-epileptic drugs such as vigabatrin and lamotrigine.