reducing to 1 6 ml/s at 72 weeks.'2 These selective adrenergic blockade has an adjunctive role in ml/s at six weeks, cc, observations suggest the development of tolerance. Alter- treating symptomatic benign prostatic hyperplasia and pro- natively a more likely explanation is that the cc blockade vides an alternative to surgery for those patients who are unfit results in a change in both voiding pressure and flow during for surgery, do not want surgery, or those who are on waiting for surgery. voiding and that these effects on detrusor function take more lists CHRISTOPHER CHAPPLE than a month to occur, reducing the potential for any increase in flow rate. Supporting the suggestion that there is a gradual Consultant Urological Surgeon, Royal Hallamshire Hospital, change in detrusor function is the observation that detrusor Sheffield S1O 2JF instability may take up to six months to improve after prostatectomy. 1 Catalona WJ, Smith DS, Ratliff TL. Measurement of prostate-specific antigen in serum as a The best way of assessing clinical efficacy is currently the test for prostate cancer. NEngl7Med 1991: 324:1156-61. screening subject of considerable debate. Though the effect of any drug 2 Caine M, Perlberg S, Meretyk S. A placebo-controlled double-blind study of the effect of phenoxybenzamine in benign prostatic obstruction. BrJ Urol 1978;50:551-4. on symptoms is extremely relevant to clinical practice, 3 Abrams PH, Shah PJR, Stone AR, Choa RG. Bladder outflow obstruction treated with phenoxy- Res symptom scores are difficult to quantify and validate. Con- benzamine. Prog Clin Biol 1981;78:269-75....