An observational urodynamic evaluation of men with lower urinary tract symptoms treated with doxazosin.

OBJECTIVES

To assess the urodynamic changes in men with lower urinary tract symptoms (LUTS) suggestive of bladder outlet obstruction treated with doxazosin and to correlate these changes with voiding symptoms.

METHODS

Fifty patients with LUTS were treated with doxazosin at a dose of 4 mg/day for 3 months. All men were initially evaluated by International Prostate Symptom Score (I-PSS) questionnaires, measurements of urinary flow rate, and complex urodynamic study. Those patients completing the 3-month study underwent repeat testing.

RESULTS

Forty-four (88%) men underwent initial and follow-up urodynamic evaluation. The mean I-PSS improved from 20.6 to 10.5 (P < 0.001), mean peak urinary flow rate increased for 11.7 to 13.2 cc/s (P = 0.20), mean detrusor pressure at peak flow decreased from 9 3.6 to 83.0 cm H20 (P = 0.15), and mean cystometric bladder capacity increased from 266 to 304 cc (P = 0.07). Using the Abrams-Griffiths nomogram and number, more than 58% of patients remained obstructed after treatment with doxazosin for 3 months. Men with and without objective evidence of bladder outlet obstruction at the outset of the study had similar improvement in voiding symptoms. Most patients elected to continue treatment with doxazosin at the completion of the study (41/44, 93%).

CONCLUSIONS

The majority of patients had objective evidence of persistent bladder outlet obstruction after treatment with doxazosin for 3 months despite significant benefit. The results of complex urodynamic evaluation did not predict treatment response in men with LUTS suggestive of bladder outlet obstruction. Urodynamic study does not appear to be helpful in the evaluation of patients with uncomplicated LUTS prior to treatment with doxazosin.