Multidrug therapy effective in neurogenic bladder

Nov 01, 2009

Alpha-blockers, tricyclic antidepressants, or both can improve compliance, lower pressures at bladder capacity, and improve reflux, incontinence, and detrusor overactivity in neurogenic bladder patients.

Key Points

Ann Arbor, MI-Alpha-blockers, tricyclic antidepressants, or both can improve compliance, lower pressures at bladder capacity, and improve reflux, incontinence, and detrusor overactivity in neurogenic bladder patients, according to researchers from the University of Michigan, Ann Arbor.

Researchers retrospectively evaluated their neurogenic bladder population, comparing patients' urodynamic status at presentation and after starting them on additional drugs, in line with what has become standard practice at the University of Michigan, based on the research of Edward McGuire, MD. The approach differs from what is still mostly standard: antimuscarinic agents only.

But with this multidrug approach, said lead author Anne Pelletier-Cameron, MD, she and her colleagues are avoiding having to perform augmentation cystoplasty or use botulinum toxin A (Botox) injections.

As reported at the AUA annual meeting in Chicago, the 77 neurogenic bladder patients in the study were severely neurologically affected: 72% were either quadriplegic or paraplegic, with most having spinal cord injury or spina bifida. All underwent fluoroscopic urodynamics when they received either no drug or antimuscarinics alone as well as after their medical therapy was optimized.

A typical regimen was either extended-release oxybutynin (Ditropan XL), 15 mg daily, or extended-release tolterodine (Detrol LA), 4 mg daily, and/or imipramine (Tofranil), 10 mg three times per day and/or terazosin (Hytrin), 2 mg once per day. Doses are titrated based on tolerability, explained Dr. Pelletier-Cameron, assistant professor of urology at the University of Michigan.

She said her typical starting regimen for a neurogenic bladder patient may include one of the newer-generation antimuscarinics-darifenacin (Enablex), 15 mg, for example-imipramine, 10 mg twice per day; and terazosin, 2 mg once per day.

Analysis was done on three groups: those receiving no drug therapy on presentation who were then increased to two drugs, those receiving no drug therapy and then increased to three, and those receiving antimuscarinics at presentation who were then increased to three drugs.

In the first group (zero to two drugs), maximum cystometric capacity increased from 160 mL to 251 mL; the second (zero to three drugs), from 156 mL to 263 mL; and there was no significant change in the third group (antimuscarinics going to three drugs). Pressure at maximum capacity and compliance, however, improved significantly in all groups. Pressure at maximum capacity decreased 52% in the first, 67% in the second, and 60% in the third group. Compliance increased five-fold in the first, 9.7-fold in the second, and three-fold in the third group. Incontinence episodes between catheterization, detrusor overactivity, and reflux also improved.

Which drug to use depends very much on the patient, explained Dr. Pelletier-Cameron.

"Typically we place spinal cord-injured patients on the alpha-blocker first because it can improve autonomic dysreflexia symptoms as well, and then imipramine," she said. "If a patient has an open bladder neck, we tend to start them on the imipramine first because the alpha-blocker may increase their incontinence."