If I were in this situation, Stephen, I’d take the allopurinol down to 100mg per day. Then, if I tolerated that, I’d increase it in very small amounts – a process known as allopurinol desensitization. Your rheumatologist should be able to decide on the dose increase, and interval.
One reason why I suggest this over febuxostat is because that drug is also associated with dizziness in pre-market trials. Also, allopurinol has a longer safety record, and it is much cheaper.
Allopurinol Desensitization is one option for allopurinol intolerance