Allopurinol is an externally administered medicine. It is sold under numerous brand names with Zyloric and Zyloprim being the most common ones.
Allopurinol is used to treat high levels of uric acid in the bloodstream. It works by reducing the amount of uric acid present, and hence, serves as a means of treatment and prevention of conditions like gout and kidney stones. It is also given to patients receiving cancer chemotherapy treatment as they have high levels of uric acid.