ALLOPURINOL AND CARBAMAZEPINE

There is some evidence to suggest that high-dose allopurinol (15 mg/kg or 600 mg daily) can gradually raise serum carbamazepine levels by about one-third. It appears that allopurinol 300 mg daily has no effect on carbamazepine levels.
This interaction may take weeks or months to develop. Warn patients taking high- dose allopurinol to monitor for indicators of carbamazepine toxicity, which include nausea, vomiting, ataxia and drowsiness. Monitor carbamazepine levels as necessary.