An assessment of serum and red blood cell folate concentrations in patients with epilepsy on lamotrigine therapy.

Lamotrigine (LTG) is a new antiepileptic drug which is effective in refractory epilepsy and which has been shown to have weak antifolate properties in vitro. The effect of LTG on serum folate and red cell folate (RBC) concentrations was assessed in a series of 14 patients on short-term LTG treatment during a placebo-controlled double-blind study. A further 14 patients who had been treated with LTG for up to 5 years were also assessed. In the short-term double-blind study the baseline mean serum folate concentration was 2.7 ng/ml and mean RBC folate concentration was 295 ng/ml. After 12 weeks of LTG therapy mean concentrations were 3.3 ng/ml and 339 ng/ml respectively and corresponding levels after 12 weeks of placebo were 2.4 ng/ml and 288 ng/ml. Patients on chronic LTG therapy showed no significant difference in RBC folate concentrations compared to those prior to LTG therapy (346 compared to 407 ng/ml). Other biochemical and haematological parameters were unaltered by LTG therapy. Thus, neither short-term nor chronic LTG therapy appears to be associated with significant changes in serum or RBC folate concentrations.

RCT Entities:   Population Interventions Outcomes