Hydroxyurea and infected stones.

The formation of struvite stones is closely linked to the enzyme urease produced by certain bacteria found in urine. It has been shown that hydroxamic acids will block the activity of this enzyme. One of these, hydroxyurea, in a morning dose of 500 mg. was used in 21 patients for three months or longer. Most were then able to acidify their urine despite persistent urinary infection. After three months, treatment with nitrofurantoin (Macrodantin and hydroxyurea (Hydrea), 78.6 per cent of patients had persistently sterile urine. There are 11 patients who have been observed for one year, and no toxic effect of the drug has been found. Three patients have shown some decrease in size of their retained calculus. This experimental study has shown that hydroxyurea may be useful in the management of struvite stones and deserves further study.