Commonly prescribed incontinence drug may help control symptoms of overactive bladder

May 22 2005

A commonly prescribed incontinence drug may help patients in more than one way, according to research completed by the University of Pittsburgh.

When taken orally, trospium chloride not only helps control symptoms of overactive bladder systemically, but according to this study, it also may help control symptoms in the bladder itself when it comes into contact with the bladder walls. Results of this study are being presented today at the annual meeting of the American Urological Association (AUA) in San Antonio, and are published in abstract 542 in the AUA proceedings.

"When taken orally, certain classes of drugs can control the muscle contractions that cause conditions like overactive bladder. In this study, we have found one drug, trospium, reacts with the bladder muscle as urine is stored in the bladder," said Michael Chancellor, M.D., professor, department of urology, University of Pittsburgh School of Medicine. "It is exciting to see that this drug could be helping the same patients in more ways than we had previously thought."

In the study, urine samples from human subjects taking the anti-muscarinic drugs trospium, tolterodine LA and oxybutynin XL and from control subjects were instilled into the bladders of animal models.

Researchers induced bladder overactivity using carbachol. The trospium bladder did not react to the carbachol, indicating that the trospium had a topical effect on controlling the muscle contractions. In the control, tolterodine- and oxybutynin-treated bladders, the length of time between bladder contractions and the bladder's capacity were decreased - representing overactive bladder-type conditions and indicating no topical effect.

Anti-muscarinic drugs block receptors in the bladder responsible for smooth muscle contractions; by easing the muscle contractions, the number of incontinence episodes are reduced and bladder capacity is increased. Common urologic conditions like overactive bladder are caused by involuntary contractions of the detrusor muscle, which controls the bladder.

More than 17 million Americans suffer from overactive bladder, a condition that significantly affects the patient's quality of life. An estimated 80 percent of these patients do not seek help or treatment for this condition. Overactive bladder is characterized by the following conditions: frequency - urinating more than eight times in a 24 hour period; urgency - the immediate and strong urge to urinate; and urge incontinence - the inability to suppress urgency, resulting in the leaking or loss of urine.