WEIGHT-GAIN IN EPILEPTIC PATIENTS DURING TREATMENT WITH VALPROIC ACID- A RETROSPECTIVE STUDY

Background: Weight gain has been recognized as a common adverse effect of valproic acid (VPA) that leads to discontinuation in some patients but its incidence and correlates have been rarely studied. Methods: W e have analyzed the records retrospectively and interviewed 70 adult p atients attending an epilepsy clinic on VPA mono-or polytherapy follow ed over a median of 27 months (range 3-189), as well as 20 patients on carbamazepine (CBZ) monotherapy. Patients were divided into non-weigh t gainers (< 5% baseline body weight), mild-moderate weight gainers (5 -10% body weight) and marked weight gainers (> 10% body weight). The f ollowing variables were statistically analyzed to determine their rela tionship to weight gain: gender, age, body mass index, drug dose perso nal or family history of obesity and monotherapy versus polytherapy. R esults: Seventy-one percent of the VPA group were weight gainers versu s 43% in the CBZ group. A weight gain of more than 4 kg in 70% of the VPA group was observed. The weight gain was often sustained and freque ntly socially significant to the patients. Patients below or within no rmal range body mass index prior to the start of VPA experienced the m ost severe percentage weight gain, From the structured patient intervi ews, patients with no personal history of weight problems experienced the greatest initial weight increase, Conclusion: Strategies should be devised to help patients avoid weight gain when starting on VPA, espe cially if they are not already overweight.