Allopurinol should not be started new during an acute gout attack as it may make the attack worse.
Allopurinol has not been well studied in pregnancy. Human data suggests that risks may be low and that allopurinol may be safe, but before starting allopurinol tell your healthcare provider if you are pregnant or planning to become pregnant.
Allopurinol does pass into breast milk. Allopurinol is likely safe in breast feeding although human data is limited. Allopurinol is considered by the American Academy of Pediatrics to be compatible with breastfeeding. Breastfed infants of mothers receiving allopurinol should be monitored for signs of allopurinol side effects, such as rash. Infants whose mothers require treatment with allopurinol may also require periodic blood work.
Allopurinol interacts with a number of other medications. Please speak with your healthcare provider about whether any of the other medications you currently take interact with allopurinol.
Anyone who is hypersensitive to allopurinol or has had a previous allergic reaction to allopurinol should avoid the medication.