OAB patients continue medical therapy unnecessarily

November 20, 2018

A recent study found that sacral neuromodulation monotherapy was efficacious as a third-line treatment.

San Francisco-Findings of a retrospective review of patients treated with sacral neuromodulation (SNM) for overactive bladder (OAB) speak to the modality’s efficacy as third-line therapy, but also point to a need to better understand why some patients continue concurrent medical therapy, said Katherine Amin, MD, at the AUA annual meeting in San Francisco.

In a study that included data from 78 patients followed for a median of approximately 16 months after the SNM procedure, the authors found that 64 patients (82.1%) stopped and never restarted their OAB medications. Comparisons with the group of individuals who continued to consistently fill an OAB medication prescription for 1 year or more showed the two cohorts differed significantly only in age, with the patients remaining on medical therapy being older than their counterparts utilizing SNM alone (74.5 vs. 64.9 years, p=.004).

Other comparisons showed the two groups were similar with respect to body mass index, sex, SNM revision rate, urodynamic parameters, patient-perceived percentage of improvement, and Patient Global Impression of Improvement (PGI-I) score.

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“Considering that symptom improvement and patient satisfaction were equivalent in the groups that discontinued and remained on OAB medications, we believe that SNM can successfully treat OAB and avoid the adverse effects of OAB medications, which may include detrimental cognitive effects with long-term usage of agents with anticholinergic activity,” said Dr. Amin, fellow in female pelvic reconstructive medicine and surgery at Virginia Mason, Seattle.

Next:Reasons for medication use unclearReasons for medication use unclear

“Further study is needed to understand the reasons why some patients continued on their OAB medications. Perhaps their condition is extremely refractory to treatment or maybe they were not adequately informed about the potential to stop their medications. Meanwhile, at our institution we are trying to ensure that patients are fully counseled so that they realize they may have the opportunity to discontinue their medication after SNM surgery,” said Dr. Amin, working with Alvaro Lucioni, MD, and colleagues.

Patients undergoing SNM during the study period were excluded from the analysis if they had the procedure for urinary retention or subsequently underwent SNM removal. Data about patient demographics, baseline characteristics, and improvement after SNM were extracted from the patients’ electronic medical records. Information on medication use was identified using an external prescription database.

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“The prescription database at our institution allows for complete tracking of when patients refill their medications,” Dr. Amin said.

Patients were categorized as remaining on concurrent medication therapy if they filled a prescription for an OAB medication for at least 11 consecutive months in the first year after SNM. Of the 10 patients remaining on concurrent medication therapy, seven were using an anticholinergic agent, one patient was on a beta-3 agonist, and two patients had filled prescriptions for both types of medications.

The majority of patients included in the study were female. For the overall population, mean body mass index was about 29 kg/m2, and mean maximum cystometric capacity was 320 mL. Detrusor overactivity was present in 75% of patients remaining on concurrent therapy and 48% of those who utilized SNM alone, but the difference between groups was not statistically significant.

SNM revision was performed in 10% to 11% of patients in the two groups.

At last follow-up, mean PGI-I score was 2 (much better) in the patients who used SNM alone versus 3 (a little better) in the concurrent group. Mean patient-perceived percentage of improvement was 60% in the SNM-alone group and 30% in the concurrent group. The between-group difference was not statistically significant for either endpoint.