More than 50% of patients taking an anticholinergic drug for symptoms of overactive bladder (OAB) stop taking their medicine—and at least half of those stop within the first 6 months. Two-thirds of patients never start again. That’s according to a study by researchers from Beaumont Hospital in Royal Oak, Michigan; Xcenda, LLC in Palm Harbor, Florida; and Allergan, Inc. in Irvine, California, who analyzed medical, pharmacy, and other data from the IMS LifeLink Health Plan Claims Database of 103,250 patients with OAB.
Anticholinergic drugs included oxybutynin, tolterodine, trospium, fesoterodine, and solifenacin, but 42% of patients received tolterodine extended release (ER) as their index prescription. To be considered a discontinuation, the patient had to have a gap of at least 45 days in therapy, based on fill dates and days’ supply. The corresponding time to treatment failure (TTF) was estimated as the number of days between the index date and the date of the first medication switch or estimated discontinuation date. Treatment reinitiation was defined as the documentation of a filled prescription for any anticholinergic agent after a discontinuation period of at least 45 days. The researchers in this study used claims data to avoid the problem of self-reported adherence, since patients often overstate their adherence to medications.
Initial treatment with the index drug failed in nearly all (92%) patients. Of those, only 6% were associated with switching drugs. More than half had permanently stopped all anticholinergic drugs at 24 months. Moreover, 33% of patients filled only 1 prescription, suggesting early failure (within the first 30 days).
The proportion of treatment failures was high across all primary diagnoses, ranging from 89% to 97%. Failure was also high regardless of the therapy. For instance, 90% of 43,902 patients on tolterodine ER and 96% of 2,246 patients on oxybutynin transdermal did not meet treatment goals. The researchers then took those numbers and pooled outcomes across all drugs to estimate the overall impact of anticholinergic treatment for patients with OAB and found that the mean TTF was 159 days.
Many patients (81%) who switched treatment during the 24-month study period also had no luck with the second drug. Treatment also failed for 29% who tried a third drug. Treatment failure didn’t always stop them from trying, though: About one-third started treatment again after a gap of at least 45 days, and about one-fifth restarted after 1 year.
Empirical studies of medications to treat chronic conditions have found persistence to OAB medications to be very low, the researchers say. When compared with oral antidiabetic drugs, angiotensin receptor blockers, statins, bisphosphonates, and prostaglandins, OAB medications had the lowest persistence rates at 6 months: 32% compared with 72% for oral antidiabetes drugs.
In research of patients with OAB, achievement of treatment goals is a strong predictor of treatment satisfaction, and dissatisfaction with treatment outcomes is the most common reason for patients stopping their treatment. Poor adherence to OAB drugs can have a negative impact on quality of life and increase the risk of medical sequelae, such as urinary tract infections. Thus, when anticholinergics fail, the researchers say, it’s important to give patients options, such as botulinum toxin A, sacral neuromodulation, and percutaneous tibial nerve stimulation.
Despite the “potential for better adherence” with some anticholinergic drugs, their findings suggest that the benefits of anticholinergic use in OAB are not being realized, and many patients may end up without any drug therapy at all.
Source
Chancellor MB, Migliaccio-Walle K, Bramley TJ, Chaudhari SL, Corbell C, Globe D. Clin Ther. 2013;35(11):1744-1751.
doi: 10.1016/j.clinthera.2013.08.017.