From experimental evidence, we know that allopurinol reduces oxygen use by myocardium, so researchers have wondered whether this drug is capable to obtain some benefits in patients with heart ischemia. Some English researchers have performed a crossover trial randomizing 60 subjects with strain-induced stable chronic angina, shown with angiography, with positive ergometric test, to add also 600 mg/die of allopurinol or placebo, for 6 weeks, to their usual therapy. After this period, subjects have been shifted to the contrary treatment for 6 further weeks. A stress test has been performed after randomization and after the end of each treatment period. Compared with patients treated with placebo, the ones treated with allopurinol have presented a significant extension in exercise time (393” vs. 307”), an extension in the average time for the onset of ST elevation (298” vs. 249”) and a greater delay in the onset of ischemic symptoms (304” vs. 272”). No side effects have been recorded.
The positive results obtained with allopurinol are comparable with the ones obtainable also with other drugs, like amlodipine and nitrates; the difference is that the mechanism of action, up to now, has not been cleared up yet (a reduction in the oxidative stress? An improvement in the endothelial function?). We will see whether further trials clear up this matter.
