Letters

Acute urinary retention in men

Management is more complex issue than was described

Authors' reply

Management is more complex issue than was described

EDITOREmberton and Anson's review of acute urinary retention was timely and informative.¹ In part of it they focused on the use of finasteride to reduce the risk of the disease.² We disagree with them that the continuous administration of finasteride for four years is probably warranted in men with large prostates, moderate to severe symptoms, and poor urinary flow rates.

Firstly, the cost implications are enormous. To prevent one event (acute urinary retention or prostatectomy) 15 patients would have to be treated for four years at a cost of £19 475.³ Secondly, the reduction in mean symptom scores with long term finasteride treatment is small (mean reduction 3.3 points) and not comparable with the results obtained after prostatectomy (mean reduction 19.4 points).⁴ Furthermore, what should happen after four years of treatment has not been established. Should finasteride treatment be stopped, with the probability of prostatic regrowth, or should patients take it for life? The answers are not known. We therefore conclude that long term finasteride is not efficient or cost effective in preventing acute urinary retention and that prostatectomy should remain first line treatment in such patients.

The review also describes patients with drained bladder volumes of more than 1 litre and low detrusor pressures who have a worse outcome (failure of catheter removal or failure of prostatectomy). Most urologists would describe this group as having chronic urinary retention, although there are no agreed criteria defining this condition. Uniform standards are urgently needed to evaluate data and therefore compare different treatments.

Jeremy J Elkabir, higher surgical trainee in urology. 
the.elk{at}virgin.net

Anup Patel,  consultant urologist. 
Justin A Vale,  consultant urologist. 
Ross O'N Witherow,  consultant urologist. 
St Mary's Hospital, Imperial College of Science Technology and Medicine, London W2 1NY

Authors' reply

EDITORThe principal concern of Elkabir et al relates to the cost of preventing one episode of acute urinary retention by use of finasteride. Unfortunately, their calculation was incorrect. Their mistake was to apply the overall treatment effect (finasteride v placebo) to their analysis rather than calculate the numbers needed to treat for the group of men whom we deliberately specified in our review. We suggested that finasteride might be of use in those men at increased risknot overall risk. In other words, those men with large prostates, high symptom scores, and low flow rates. In treating men with symptoms a 50% risk reduction for long term complications is achieved in addition to the health gain conferred by a reduction in symptoms. The analysis of Elkabir et al highlights the danger of "back of the envelope" economic assessment. An evaluation more in line with Drummond and Jefferson's guidelines for economic submissions to the BMJ¹ was recently proposed. By analysing decisions based on models in which transitions were triggered by urological events, non-surgical failure, and natural mortality over a two year time frame, Albertsen et al concluded that finasteride showed cost savings compared with terazosin in appropriately selected patients.² These cost savings were largely due to a reduction in the rates of acute urinary retention in men and the need for prostate surgery. Moreover, their findings seemed to be robust over a range of model assumptions and costs.

The other points of Elkabir et al were both raised and answered by them. Firstly, no one would argue that drug treatment and prostatectomy confer the same reduction in symptoms. Secondly, we, like Elkabir et al, cannot comment with any authority on intermittent treatment as no trials have addressed this question. Finally, the patients who had high volumes of urine drained from the bladder at the time of catheterisation were in sudden, painful retention of urine. Most people would call this acute retention of urine.

Mark Emberton,  senior lecturer in oncological urology. 
Institute of Urology and Nephrology, University College Hospital, London W1P 7PN memberton{at}dial.pipex.com

Ken Anson,  consultant urologist. 
St George's Hospital, London SW17 0QT