The role of alpha-blockers in the management of acute urinary retention caused by benign prostatic obstruction.
OBJECTIVE
To consider theories concerning the etiology of acute urinary retention (AUR), which may influence the outcome of a trial without catheter (TWOC), and to discuss evidence regarding the use of medical therapy in the management and secondary prevention of AUR.


METHODS
A search of the literature discussing measurable parameters that may identify patients at risk for AUR and who require further intervention after initial treatment was undertaken. Studies of the effect of medical interventions for benign prostatic hyperplasia (BPH) and AUR were also identified.


RESULTS
The etiology of acute urinary retention remains unknown in many cases, which are often described as spontaneous, but catheterization remains standard management followed by a TWOC and bladder outlet surgery in those who do not void satisfactorily. Alpha-blockers (alpha(1)-adrenoreceptor antagonists) effectively reduce the symptoms associated with BPH and improve the urodynamic parameters of obstruction, without the sexual adverse events associated with the 5alpha-reductase inhibitors. They may diminish the incidence of AUR and the need for surgical intervention in symptomatic men. There is now good evidence that alfuzosin, in particular, improves the success rate of a TWOC, although other uroselective alpha-blockers have also been shown to improve the success rates of TWOC.


CONCLUSIONS
The proven effects of alpha-blockers support the hypothesis that they will increase the chances of a successful TWOC following AUR, which has now been proven in several well-designed and conducted studies. However, it is not yet clear whether these or other medical therapies have a role to play in the secondary prevention of further AUR or the need for further surgery. It is clear that certain measurable parameters may be used to identify patients at highest risk of a further episode of AUR following a successful TWOC; these patients may then be offered urgent surgical intervention.
Alan McNeill
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Department of Urology, Western General Hospital, Edinburgh, Scotland, UK. alan.mcneill@luht.scot.nhs.uk
D000208:Acute Disease; D000317:Adrenergic alpha-Antagonists / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D011470:Prostatic Hyperplasia / Q000150:complications*; D011788:Quality of Life; D012307:Risk Factors; D016055:Urinary Retention / Q000188:drug therapy* / Q000209:etiology*
D000317:Adrenergic alpha-Antagonists