Updated

Botox injections may be best known for smoothing facial lines, but they may also help soothe an overactive bladder, a small study shows.

UK researchers found that among 34 patients with stubborn overactive bladder symptoms, those treated with Botox showed improvements in symptoms and quality of life that lasted up to six months.

The findings, published in the journal BJU International, add to evidence that Botox may aid people with overactive bladder symptoms that resist standard therapy.

Botox, which is derived from botulinum toxin, works by interfering with nerve signals in the treated muscle, essentially paralyzing it. Administered to the muscles of the bladder, Botox is believed to prevent the spasms that create the symptoms of overactive bladder — a strong, frequent urge to urinate, sometimes accompanied by leakage.

For the current study, Dr. Arun Sahai and colleagues at Guy's Hospital and King's College London randomly assigned the 34 patients to receive either Botox injections or a placebo for comparison. All of the men and women had tried oral medication for their symptoms but failed to improve.

The Botox treatment was delivered via a thin, flexible tube called a cystoscope. Each patient received 20 injections through the bladder wall to various sites on the bladder muscles.

After one month, Sahai's team found, the subjects given Botox injections reported a greater improvement in symptoms, as well as quality of life — including fewer physical limitations and a better social life — than the placebo patients. In general, many of the benefits were still present 24 weeks after treatment.

Along with symptom improvement, Sahai's team notes, a boost in quality of life is "perhaps of most importance" to people with overactive bladder.

All of the researchers on the study are also investigators for Botox maker Allergan Ltd.