AVP and xanthinuria type I: Reduced levels of UA are seen with a variety of medications (allopurinol, aspirin, probenacid, coumadin, corticosteroids), liver disease, alcohol use, Wilson's disease, hemochromatosis, protein or purine deficiency, xanthine oxidase deficiency, syndrome of inappropriate ADH secretion (SIADH) or renal tubule disease [58].