My brother is a 61 year old, 6 1 African American man who weighs only 125 pounds. He eats, but doesn t seem to gain much weight. He has had lab work (a1c, thyroid, psa, occult stool, urine analysis cbc) done and everything came back normal. He has seizure disorder and takes the following medications: Keppra - 5,000 miligrams daily, Vimpat - 500 miligrams daily, Topamax - 150 miligrams daily, Banzel - 800 miligrams daily, Diazepam - 1cc as needed to control seizures. He also takes a multi-vitamin and a calcium supplement daily. Though there is no signs of a rash, he complains of itching, but mostly at night. Can you tell me why he doesn t gain weight.