Alpha blockers prior to removal of a catheter for acute urinary retention in adult men

Background Acute urinary retention is a urological emergency in men and requires urgent catheterisation. Any intervention which aims at increasing the rate of a successful trial without a catheter following an acute urinary retention episode would be considered potentially beneficial. Alpha blockers relax prostatic smooth muscle cells thereby decreasing the resistance to urinary flow and by doing so improve urinary symptoms. Objectives To assess the effects of alpha blockers on successful resumption of micturition following removal of a urethral urinary catheter after an episode of acute urinary retention in men. Search methods We searched the Cochrane Incontinence Group Specialised Register (11 February 2009) and the reference lists of relevant articles. No language or other restrictions were imposed on the searches. Selection criteria Only randomised and quasi-randomised clinical trials of alpha blockers for trial without a urethral catheter following an episode of acute urinary retention in men were included. Data collection and analysis Both review authors independently examined all the citations and abstracts derived from the search strategy. Any disagreement about trial selection and inclusion was resolved by discussion. A third independent judgement was sought where disagreement persisted. Both review authors extracted independently, cross-checked and processed the data as described in the Cochrane Collaboration Handbook (Higgins 2008). Main results Five randomised clinical trials were eligible for inclusion in this review. All five trials compared alpha blockers versus placebo. In four trials alpha blockers were used between 24 to 72 hours (in one study up to a maximum of eight days) before trial without a catheter (TWOC); in one trial alpha blockers were used for eight days prior to trial without a catheter. Four trials tested alfuzosin and one trial tested tamsulosin. Four trials favoured alpha blockers and one trial favoured placebo. Overall rates of successful TWOC tended to favour alpha blockers over placebo. This was statistically significant (RR 1.39, 95% CI 1.18 to 1.64) irrespective of the alpha blocker used (alfuzosin: RR 1.31, 95% CI 1.10 to 1.56; tamsulosin: RR 1.86, 95% CI 1.17 to 2.97). With regard to causing fewer vasodilatation-related side effects (for example hypotension, dizziness), two studies favoured placebo and one favoured alpha blockers. Overall side effects were low for both placebo and alpha blockers. Failure rates were high and mainly caused by the need for re-catheterisation rather than vasodilatation-related side effects. Authors' conclusions The limited available evidence suggests that alpha blockers increase success rates of TWOC. Alpha blocker side effects are low and comparable to placebo. It is uncertain whether alpha blockers reduce the risk of recurrent urinary retention and need for prostate surgery. The cost effectiveness and recommended duration of alpha blocker treatment after successful TWOC remains unknown. There are a lack of internationally agreed outcome measures for what constitutes successful TWOC. This makes meta-analysis difficult. More randomised clinical trials are needed to address these issues.