P8 – 2228: The effects of anti-epileptic drugs on the growth plates of infant rats

“Epilepsy is among the most common neurologic disorders in childhood. Levetiracetam (LEV) and valproic acid (VPA) are widely used drugs in the treatment of children with epilepsy. The adverse effects of both drugs on bone metabolism and growth is defined in the literature. The present study aimed to investigate the effects of these two common anticonvulsant drugs on longitudinal bone growth in rats.

Twenty-four infant rats divided into three groups. The study groups received VPA (600 mg/kg/day) and LEV (150 mg/kg/day) for two weeks respectively. Normal saline was applied to the control group. The rats were sacrified after the appliance of the drugs and the rat femurs were removed. The thickness of the growth plates were measured by histopathologically.

All groups included four males and four females. The thickness of the growth plates were larger in VPA and LEV groups versus control group (p<0.05). In addition the measurement of the growth plate in VPA group was larger than LEV group (p<0.05).

We concluded that VPA and LEV both enlarge the growth plate on rats in this study. But this finding does not reflect all steps of endochondral bone growth. The hormonal factors and apoptotic processes also have role on longitudinal bone growth. Further investigations are needed to clarify the adverse effects of anticonvulsants on bone growth and influence on final height.”

Note though that enlargement of the growth plate does not always equal larger longitudinal bone growth.