Drug therapy rarely warranted in incontinent children

"My personal belief is that very few children require pharmacotherapy for incontinence," said Douglas A. Canning, MD, chief of the division of urology at Children's Hospital of Philadelphia and professor of surgery (urology) at the University of Pennsylvania School of Medicine.

"If you are going to prescribe medicines to children, then you have to select drugs that have very few side effects," he said in a lecture at a recent conference on incontinence in the pediatric population, co-sponsored by the International Children's Continence Society and USF Health at the University of South Florida, Tampa.

"Remember," he said, "no one has ever died of wetting, although some who wet wish they had."

Proceed cautiously

Before going to pharmacotherapy, Dr. Canning said, clinicians should try diet therapy; the use of stool softeners and bulking agents to fight constipation; behavioral management, such as timed voiding, increased hydration, and improved elimination; and biofeedback. He said that approximately 85% to 90% of children seen in clinics because of wetting respond to those therapies. Only if those therapies fail should the doctor consider drug therapy.

"If you do need to use pharmacotherapy," Dr. Canning said, "it should be tailored to the child. Start broad and gain precision."

Generally, he said, pharmacotherapy is appropriate in children with overactive bladder, primary bladder neck dysfunction, or a congenitally small bladder.

Dr. Canning said one problem with using drugs for incontinence is that several of them cause constipation, and constipation is a major cause of incontinence in children.

"One of the side effects of treatment with oxybutynin [Ditropan] and imipramine [Tofranil]-neither of which have proven effective in children-is that these drugs cause constipation," he explained. "We know that stool in the rectum may displace the bladder, reducing room for bladder filling. This may make it more difficult for the child to avoid wetting. That can make these drugs counterproductive."

His conservative approach to treating children with incontinence was backed by Howard M. Snyder, MD, professor of surgery in urology at the University of Pennsylvania School of Medicine.

"Hardly ever would pharmacotherapy be appropriate for children with incontinence. In almost every case, these are problems that can be resolved with changes in diet or behavior," Dr. Snyder said.

In his presentation, Dr. Canning reviewed the drugs used to treat incontinence in children.

He cautioned that antimuscarinics, used for treatment of overactive bladder, also affect the central nervous system, the lacrimal gland responsible for lubrication of the eye, salivary glands, the heart, the gallbladder, the stomach, and the colon. Other pharmacologic approaches include injections of botulinum toxin (Botox) into the urethra and the oral use of alpha-1 antagonists, both of which can help reduce resistance at the bladder neck. (Botulinum toxin is not FDA-approved for this indication, and not all alpha-1 antagonists are approved for this indication in children.)

Dr. Canning described the individual antimuscarinics, beginning with the former gold standard for overactive bladder, oxybutynin, an M1and M3 muscarinic receptor blocker.

"Oxybutynin is associated with high efficacy and very high side effect rates," he said.

However, oxybutynin therapy administered through a transdermal patch (Oxytrol) provides efficacy with the possible advantage of a lower incidence of dry mouth.

Tolterodine (Detrol) has gained favor as a uroselective agent that reduces the incidence of dry mouth and that pharmacokinetically shows a more balanced receptor profile, Dr. Canning said, noting that the drug lacks dosing flexibility.