I went and did 'it' my way

Anti-incontinence drug shown to reduce incontinence
episodes in clinical trials

By Chris Williams

Hilda Levi is afraid to leave her house. She's neither paranoid nor hiding from the door-to-door vacuum cleaner salesman � well not for the most part. She's staying home because the last time she went out, the 72-year-old had an 'accident' on her oldest friend's white couch. For Hilda, an overactive bladder is more than an annoyance. It's a source of mental anguish. But soon, physicians will be able to offer patients like Hilda another relief option � darifenacin (Enablex).

Darifenacin works by blocking a receptor that helps govern the bladder-encasing detrusor muscle. This stops the muscle from contracting spastically and creating the frequent and urgent need to pee. The drug was the subject of two presentations at the recent Annual Meeting of the American Urological Association in San Francisco. The seminars detailed the outcomes of separate phase III clinical trials, which confirmed the drug's effectiveness in reducing the number of both incontinence episodes and middle of the night bathroom trips.

One of the trials, led by Dr Vik Khullar of Imperial College in London evaluated the effectiveness of darifenacin vs a placebo in 439 patients over the course of six months. The trial found that the number of incontinence episodes was reduced by 77% in those taking the drug and 46% in those taking the placebo. Additionally, the frequency of sleep interruptions was reduced by 23% in the active drug group but only 3.6% in those taking the placebo. The darifenacin crowd's better night's sleep carried over into better daytime functioning, another point in the drug's favour.

Dr Christopher Chapple, of Royal Hallamshire Hospital in Sheffield, reached similar conclusions based on a 12-week double- blind placebo-controlled study of 1,049 people. He found that the increased relief from incontinence didn't come at the expense of the central nervous system or cardiovascular function, whose activity is partially governed by receptors similar to the receptor blocked by darifenacin.

"Enablex may be an important new treatment option for overactive bladder," commented Dr Khullar. Others take a less enthusiastic view. "Right now [darifenacin] has a theoretical edge, but it is certainly not a proven edge," said University of Pennsylvania urology professor Dr Alan Wein. "The only way to prove the edge is by comparing it to the other drugs in head-to-head studies."

In Canada, urologist Dr Luc Valiquette, who sits on the governing board of The Canadian Continence Foundation, is also taking a wait-and-see approach. "This product is interesting, with possibly less side effects than the other products, but it is not a major breakthrough."

Whether darifenacin is a major breakthrough or not remains to be seen, but at the very least it presents doctors and patients with another treatment option for incontinence.