title: Further studies on allopurinol therapy and human cataractogenesis.
abstract: We examined 11 cataractous lenses (or aspirated lens matter from extracapsular extractions) from patients ranging in age from 55 to 84 years who used allopurinol on a long-term basis (more than two years). Phosphorescence analyses demonstrated the characteristic allopurinol triplet in these lenses. When we analyzed normal lenses from patients taking allopurinol in a similar manner we found no evidence of allopurinol photobinding. These data indicated that allopurinol has a cataractogenic action only in patients in whom the drug has become photobound within the lens. Long-term allopurinol therapy does not necessarily cause or enhance cataracts in all patients. There may be a relationship between ultraviolet radiation exposure and circulating allopurinol levels (and perhaps renal function) in the genesis of photosensitized allopurinol cataracts.
mesh_terms: D000368:Aged; D000493:Allopurinol / Q000009:adverse effects* / Q000032:analysis; D002386:Cataract / Q000139:chemically induced*; D006073:Gout / Q000188:drug therapy; D006801:Humans; D007908:Lens, Crystalline / Q000032:analysis / Q000528:radiation effects; D008875:Middle Aged; D013050:Spectrometry, Fluorescence; D013997:Time Factors; D014466:Ultraviolet Rays / Q000009:adverse effects
chemical_list: D000493:Allopurinol