PDE also likely improves symptoms when used in combination with 5-alpha reductase inhibitors. Several phosphodiesterase-5 inhibitors are also effective, but may require multiple doses daily to maintain adequate urine flow. Tadalafil, a phosphodiesterase-5 inhibitor, was considered then rejected by NICE in the UK for the treatment of symptoms associated with BPH. In 2011, the U.S. Food and Drug Administration approved tadalafil to treat the signs and symptoms of benign prostatic hyperplasia, and for the treatment of BPH and erectile dysfunction (ED), when the conditions occur simultaneously. Others
Antimuscarinics such as tolterodine may also be used, especially in combination with alpha blockers. They act by decreasing acetylcholine effects on the smooth muscle of the bladder, thus helping control symptoms of an overactive bladder. Self-catheterization
Intermittent urinary catheterization is used to relieve the bladder in people with urinary retention. Self-catheterization is an option in BPH when it is difficult or impossible to completely empty the bladder. Urinary tract infection is the most common complication of intermittent catheterization. Several techniques and types of catheter are available, including sterile (single-use) and clean (multiple use) catheters, but, based on current information, none is superior to others in reducing the incidence of urinary tract infection. Surgery
If medical treatment is not effective, surgery may be performed. Surgical techniques used include the following:

Transurethral resection of the prostate (TURP): the gold standard. TURP is thought to be the most effective approach for improving urinary symptoms and urinary flow, however, this surgical procedure may be associated with complications in up to 20% of men.
While the prevalence rate is 2.7% for men aged 45–49, it increases to 24% by the age of 80 years. References
External links

Extrinsic Compression by Prostate