Factors affecting long-term dutasteride add-on treatment to alpha-adrenergic antagonist for patients with BPH

This study identified clinical risk factors that resulted in the failure of dutasteride (Avodart) add-on treatment to alpha-adrenergic antagonists for patients with lower urinary tract symptoms (LUTS) and benign prostatic hyperplasia (BPH). The authors concluded that an intravesical prostatic protrusion (IPP; the enlargement of the prostate towards the floor of the bladder) of 13 mm or more, a large prostate volume, and severe blockage are risk factors that result in treatment failure in these patients.

Dutasteride is a commonly used medication for symptoms of BPH (non-cancerous increase in prostate gland size) and LUTS. LUTS include urinary symptoms such as difficulty initiating urination, incomplete bladder emptying, a weak urine stream. Dutasteride blocks the action of an enzyme that changes testosterone into an active compound. As a result, dutasteride can help reduce the size of the prostate gland. Additionally, dutasteride may decrease the need for surgery for BPH.

However, when used alone or combined with an alpha-adrenergic antagonist (a drug that causes muscle tissue relaxation in blood vessels and in the prostate gland), it may not always be effective at improving LUTS or urinary retention.

Surgery may be needed for such patients that experience treatment failure. Treatment failure refers to the need for surgery for BPH, a requirement for intermittent catheterization or permanent bladder catheter despite medication. There is a need to investigate risk factors associated with the failure of dutasteride add-on treatment to alpha-adrenergic antagonists in men with BPH.

This study included 92 patients that received dutasteride add-on treatment to an alpha-adrenergic antagonist. Treatment failure was evaluated in patients. The average follow-up was 59.4 months.

25% of patients had treatment failure after an average of 38 months of dutasteride add-on treatment. 20 patients received transurethral prostatectomy (TURP). TURP involves the removal of prostate tissue blocking urine flow through the urethra (the tube that passes urine out of the bladder). 2 patients needed intermittent catheterization and 1 patient needed a permanent urethral catheter.

Patients with treatment failure were younger in age, had higher prostate volumes (76 ml vs 49 ml), lower voiding efficiency (54% vs 68%), and higher bladder outlet blockage. Treatment failure was also associated with IPP (prostate gland enlargement) of 13 mm or greater.

The study indicated that an IPP of 13 mm or greater, larger PV, inefficient voiding, and severe bladder outlet blockage were risk factors resulting in failure of dutasteride add-on treatment to alpha-adrenergic antagonists in patients with LUTS and BPH.

The study design affected patient selection for surgical treatment and there were no specific criteria for surgery.