my husband had a colloid cyst in 3rd ventrical and had a surgical removal, post the surgery he started having epiliptic attacks, he had 2 attacks only though in 1 yr post surgery and was on levipil for an yr, after 14 months of his surgery he was on levipil 2000 mgm per day,all of a sudden he had 3 seizures within an hour on a particular day, doctor said levipil is not suiting him and has changed his medicine to zen retard,how safe is zen retard, are there any side effects have read about weight gain on net because of this, is this true and are there any other side effects