Growth and bone metabolism were evaluated in 27 boys and 26 girls, aged 3 to 17 years (mean 9.2 yrs), with epilepsy treated with valproate (VPA) and/or lamotrigine (LTG) for >2 years, in a study at McMaster University and Children’s Hospital, Hamilton, Ontario, Canada. Height was below the 10th percentile in 23 (43.4%) of the patients, and bone mineral density (BMD) was reduced in 24%. When patients were divided according to daily activity, the inactive group had significantly lower scores for height percentile, BMD, and biochemical indices for bone metabolism, when compared with the active group. The score for total body BMD was correlated with the daily activity score. Height percentiles were significantly lower in children treated with VPA/LTG combination therapy compared to VPA-alone or LTG-alone. [1]

COMMENT. Long-term VPA and LTG therapy, especially in combination, is associated with short stature, low bone mineral density, and reduced bone formation. These effects on growth and bone metabolism are correlated with reduced physical activity. Although a specific effect of the anticonvulsant medication on growth and bone mass is unproven, further studies are indicated.