Leslie,
Uloric works well but is very expensive (especially in comparison to allopurinol which is dirt cheap). Although it is another xanthine oxidase inhibitor, its chemical structure is very different from allopurinol. I can find nothing to indicate that there is cross-sensitivity. As you may know, the PI does NOT say that it should be used with caution in those allergic to allopurinol.
Been meaning to mention your new avatar. Is that a mule or a donkey? Either way, a compliment is in order. If it is the former, I like your mule. If it is the latter, I like your new [censored].
