Alpha-1 Blocker Reduces Acute Urinary Retention Risk in the Elderly

January 10, 2005
Internal Medicine World Report, January 2005,

Alpha-1 Blocker Reduces Acute Urinary Retention Risk in the Elderly

By Walter Alexander

VIENNA—For men in their 70s with benign prostatic hyperplasia (BPH), the 5-year risk for acute urinary retention (AUR) is about 20%—for men in their 80s, the risk of AUR is 33%. Results of the ALFAUR (ALFuzosin in Acute Urinary Retention) study show that alfuzosin (Uroxatral) 10 mg/day reduces the need for surgical treatment and facilitates rapid catheter removal. This study was presented at the European Association of Urology Congress.

Alfuzosin is an alpha-1 (A1) blocker. In AUR, which is related to a high degree of sympathetic stimulation, decreasing sympathetic tone at the level of the urethra and bladder neck with an A1 blockers reduces bladder outlet obstruction and postvoid residual urine. Both, according to S. Alan McNeill, MD, of Western General Hospital, Edinburgh, United Kingdom, play a role in the development of AUR.

This study was conducted among 363 men ≥50 years old (mean age, 69 years) having a first episode of BPH-related AUR, with a retention volume between 500 to 1500 mL at time of catheterization. Following their AUR episode, patients were randomized to catheterization plus alfuzosin or placebo for 2 to 3 days (2:1, alfuzosin: placebo). Catheters were removed after 2 doses; those with successful removal (ie, no need for catheterization within 24 hours following catheter removal) were again randomized to alfuzosin or placebo for 6 months (n = 169, 1:1).

The goal of the first phase of ALFAUR was to confirm a role for alfuzosin in allowing rapid catheter removal. Phase 1 showed a significantly higher rate of successful voiding following catheter removal for those receiving alfuzosin 10 mg/day (61.9% vs 47.9%; P = .012). Benefits were more pronounced in older men (aged ≥65 years) and those with higher retention volumes (≥1000 mL), both categories conferring higher failure risk in those treated without catheters.

In phase 2, the percent of patients with a successful outcome (defined as the absence of need for surgery during the 6-month treatment period) was looked at among 85 men randomized to alfuzosin 10 mg/day and 84 to placebo.Fewer patients needed BPH surgery in the alfuzosin group. At 28 days the need for surgery was reduced by 61% (P <.05); at 84 days by 52% (P <.05); at168 days by 29% (P = .2); and at 6 months by 24% (NS). Of 83 evaluable patients, 20 required surgery. Most surgeries were required early, with 13/20 (65%) in the first month and 17/20 (85%) within the first 3 months. The overall survival rate (surgery or catheterization not required) for ALFAUR was 25% for the placebo group and 39% for alfuzosin (P = .02).

Although the 29% reduction in risk for surgery at 6 months follow-up in phase 2 did not reach statistical significance, Dr McNeill argued that delaying the need for surgical intervention with alfuzosin allows those most in need of surgical intervention to be identified. Once identified, they may be offered elective surgical intervention prior to a further episode of AUR. Surgery in the presence of a urinary catheter, research has shown, increases the risk of perioperative morbidity.

Alfuzosin was well tolerated. More adverse event-related withdrawals were reported for placebo than for alfuzosin (approximately 1.5%). “For my money, if you had AUR and you were told that with alfuzosin you have about a 40% chance of managing without a catheter, you would take it,” said Dr McNeill. “Treatment continuation over 6 months after a successful treatment without a catheter reduces the need for BPH surgery with no increased risk of adverse events.”

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