Treatment of Overactive Bladder in the Elderly Female: The Case for Trospium, Oxybutynin, Fesoterodine and Darifenacin.

Overactive bladder (OAB) is a common constellation of lower urinary tract storage symptoms that causes a significant impact on a person's quality of life. The elderly may be disproportionally impacted by these symptoms due to concomitant poor mobility, comorbid conditions such as diabetes and heart failure, and polypharmacy. While behavioral modification and pelvic floor muscle training should be considered first-line treatment options, pharmacotherapy remains the backbone of the therapeutic regimen. Trospium, oxybutynin, fesoterodine, and darifenacin all have unique properties that may confer certain advantages in the elderly population. The hydrophilicity and quaternary amine structure of trospium may limit its ability to cross the blood-brain barrier and thus minimize impact on cognition in the elderly. In its oral form, oxybutynin may have the most significant effect on cognition; however, the transdermal preparations may be favorable in the elderly population due to the ability to avoid first-pass metabolism and its limited antimuscarinic adverse effects. Fesoterodine may be the most extensively studied OAB medication in the elderly population. Darifenacin has a strong affinity for the M3 receptor in the bladder, while having a weak affinity for the M1 receptor commonly found in the brain. It must be noted that all muscarinic receptor antagonists are associated with common adverse effects to some degree, and frequent re-evaluation of the elderly patient is necessary to confirm the proper benefit-to-risk profile.