The efficacy and safety of
lamotrigine and
carbamazepine as monotherapy in patients with untreated, newly diagnosed or recurrent partial and/or generalised
tonic-clonic seizures, were compared in a randomised, open, multicentre study. Patients received 24 weeks' treatment with oral
lamotrigine 100 mg (LTG 100, n = 115) or 200 mg (LTG 200, n = 111) or
carbamazepine 600 mg (CBZ 600, n = 117). Efficacy measurements were comparable between the three treatment groups, although the higher
lamotrigine dose was possibly most effective, with 60.4% completing seizure free compared with 51.3% (LTG 100) and 54.7% (CBZ 600). Both dosage regimens of
lamotrigine were well tolerated. More patients on CBZ 600 reported adverse experiences, 66% versus 53% (LTG 100) and 58% (LTG 200), and of these a greater proportion were attributed to CBZ 600 treatment, 53% versus 23% (LTG 100) and 28% (LTG 200). Similarly, a greater proportion of the CBZ 600 group required a change in dose, 47% versus 20% (LTG 100) and 17% (LTG 200) or withdrew completely due to adverse experiences, 10.3% versus 4.3% (LTG 100) and 4.5% (LTG 200). The most common adverse experience leading to withdrawal was
rash, with approximately double the proportion of reports occurring in patients on CBZ 600 (5.1%) compared with
lamotrigine (1.7% on LTG 100 and 2.7% on LTG 200). Overall
lamotrigine appeared equally effective but better tolerated compared with
carbamazepine.