Is your bladder feeling the signs of age? Spending too much time in the bathroom? Allergan's (NYSE: AGN) Botox can help.

Of course, the wrinkle treatment isn't making patients' bladders look more youthful. Instead, the neurotoxin is reducing muscle activity, the same way it does with wrinkles and migraines, which it's currently approved to treat.

In a pair of phase 3 trials, the number of daily incontinence episodes was greatly reduced in patients who received a Botox injection compared with those who got a placebo. Allergan didn't release the full data, but based on the p-value of less than 0.001, it's pretty clear the drug works.

The results aren't all that surprising; Botox is already approved as a treatment for overactive bladder associated with a neurological condition like a spinal cord injury or multiple sclerosis or for patients who can't tolerate other drugs used to treat the condition.

Allergan expects to present the full data at an upcoming medical meeting and has already applied for expanded use in the United States and European Union.

An injection into the bladder muscle with a neurotoxin, however effective, probably isn't going to be the first choice for patients and their doctors, though. In fact, Allergan isn't even targeting those first-line patients, choosing instead to go after patients who have failed other treatments such as Pfizer's (NYSE: PFE) Detrol, Johnson & Johnson's (NYSE: JNJ) Ditropan, Warner Chilcott's Enablex (Nasdaq: WCRX), and Allergan's own Sanctura. Allergan says greater than 50% of patients discontinue oral medications, probably because of an inadequate response to or intolerance of the medication.

The treatment of overactive bladder may never reach the level of the cosmetics sales of Botox, but any incremental addition is still a welcome addition. And patients can get overactive bladders that they want to treat in good times and bad, unlike winkles that can be a little more sensitive to the economic cycles.

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