Urinary tract disorders. Clinical comparison of flavoxate and phenazopyridine.

In nine separate clinical trials, 382 patients having symptoms of either prostatitis, acute cystitis, urethritis, and/or trigonitis were randomly assigned to treatment with flavoxate or phenazopyridine. Over-all response was evaluated in 384 patients after five days of therapy. In patients having prostatitis, response was satisfactory in 66 per cent treated with flavoxate and 31 per cent treated with phenazopyridine. In all other patients, satisfactory responses were reported in 80 per cent on flavoxate compared with 56 per cent on phenazopyridine. Similarly, symptom-severity evaluations at two and five days of therapy showed most symptoms improved in more of the patients on flavoxate therapy than on phenazopyridine therapy. Although more adverse effects were reported in patients treated with phenazopyridine than with flavoxate, the difference between medications was not statistically significant.