Regulators in the USA have given the green light to Eli Lilly's erectile dysfunction drug Cialis as a treatment for enlarged prostate.

Specifically, the US Food and Drug Administration has approved Cialis (tadalafil) to treat the signs and symptoms of benign prostatic hyperplasia (BPH) and for the treatment of the latter and ED, when the conditions occur simultaneously. In two clinical trials, men with BPH (who suffer from a sudden urge to urinate and do so more frequently at night) and took 5mg of Cialis once-daily experienced a statistically significant improvement in their symptoms compared to men on placebo. In a third trial, men who experienced both ED and BPH and took Cialis had improvement in their symptoms of both.

Scott Monroe, director of the Division of Reproductive and Urologic Products in the FDA’s Center for Drug Evaluation and Research, said “BPH can have a big impact on a patient’s quality of life”. He added that "a large number of older men have symptoms of BPH [and] Cialis offers these men another treatment option, particularly those who also have ED".

The agency noted that Cialis, which was approved in the USA in 2003, should not be used in patients taking nitrates, because the combination can cause an unsafe decrease in blood pressure, and use of the drug in combination with alpha blockers for the treatment of BPH is also not recommended.

Dave Ricks, Lilly USA president, said these additional indications for Cialis "reinforce our commitment to providing medical innovation in the area of men's health". The drug is the only treatment to get the thumbs-up for both ED and BPH.

The BPH market is pretty crowded and the FDA has previously approved eight other drugs. They are Merck & Co's Proscar (finasteride) and GlaxoSmithKline's Avodart (dutasteride) and Jalyn (dutasteride plus tamsulosin), plus five alpha blockers: Abbott's Hytrin (terazosin), Pfizer's Cardura (doxazosin), Boehringer Ingelheim's Flomax (tamsulosin), Sanofi's Uroxatral (alfuzosin) and Watson's Rapaflo (silodosin).