Alfuzosin: a Review of the Therapeutic Use of the Prolonged-release Formulation Given Once Daily in the Management of Benign Prostatic Hyperplasia

Unlabelled: Alfuzosin, a quinazoline derivative, is a selective and competitive alpha(1)-adrenoceptor antagonist. It distributes preferentially in the prostate, compared with plasma, and decreases the sympathetically controlled tone of prostatic smooth muscle. As a result lower urinary tract symptoms suggestive of benign prostatic hyperplasia (BPH) are improved. The once-daily formulation of alfuzosin contains inactive barrier layers which have been added to the planar surfaces of compressed tablets. Drug release is sustained over 20 hours with a near constant dissolution rate between 2 and 12 hours. Mean values for area under the plasma concentration-time curve over 24 hours (AUC(24)) were similar after administration of prolonged-release alfuzosin 10mg once daily and immediate-release alfuzosin 2.5mg three times daily. Likewise, similar AUC(24) values were reported when prolonged-release alfuzosin 10mg once daily and sustained-release alfuzosin 5mg twice daily were compared. These data suggest that these alfuzosin regimens provide similar average systemic exposure. Data from short- (3 months) and long-term (up to 12 months) clinical trials show that the prolonged-release formulation of alfuzosin controls the symptoms associated with BPH as effectively as immediate-release alfuzosin 2.5mg three times daily and clinical improvement is maintained for up to 1 year. Improvements in International Prostate Symptom Score, maximum urinary flow rate and quality-of-life index were improved to a similar extent in patients treated with immediate- or prolonged-release alfuzosin and improvements were statistically significant compared with placebo. Prolonged-release alfuzosin 10mg is well tolerated and the overall incidence of adverse events is similar to that seen with placebo. The once-daily formulation of alfuzosin 10mg caused fewer vasodilatory adverse events than immediate-release alfuzosin 2.5mg three times daily and caused only slight decreases in systolic and diastolic blood pressure which were not clinically significant and did not differ significantly from those with placebo. No dosage titration is required. The incidence of ejaculatory disorders was <1%.

Conclusion: Prolonged-release alfuzosin 10mg once daily controls symptoms associated with BPH throughout a 24-hour dosage interval as effectively as immediate-release alfuzosin 2.5mg three times daily but with fewer vasodilatory adverse events. A nonblind extension study showed that clinical benefits were maintained for up to 1 year and the once-daily 10mg formulation continued to be well tolerated, particularly in terms of cardiovascular effects and sexual function. Thus, for the medical management of men with BPH, prolonged-release alfuzosin 10mg is an effective, well tolerated and convenient treatment option.