Acetohydroxamic acid is known to inhibit bacterial
urease activity, thus, reducing urinary
ammonia levels. A double-blind placebo-controlled clinical trial of
acetohydroxamic acid was conducted at 12 Veterans Administration
spinal cord injury units. A total of 210 male
spinal cord injury patients with chronic
urea-splitting urinary
infection was enrolled for a scheduled followup of 2 years. The study data support the usefulness of
acetohydroxamic acid in reducing urinary
ammonia. At every followup visit the
acetohydroxamic acid patients with stones had decreases in
ammonia of 30 to 48 mg. per dh., while the placebo patients had increases in
ammonia.
Acetohydroxamic acid also retarded stone growth. Patients with stones treated with
acetohydroxamic acid exhibited significantly longer intervals from randomization to first stone growth than patients treated with placebo (p less than 0.005, medians 15 versus 9 months).
Acetohydroxamic acid reduced significantly the proportion of patients with stone growth at 12 months (33 versus 60 per cent, p equals 0.017). This decrease was diminished at 24 months (42 versus 60 per cent, p equals 0.260). Patient attrition was 31 per cent in the placebo group and 62 per cent in the
acetohydroxamic acid group, the latter attrition being primarily owing to patient request because of mild symptoms. Of the
acetohydroxamic acid and placebo patients 62 and 29 per cent, respectively, reported
drug side effects but all were reversible and no unanticipated or life-threatening reactions occurred.