Patients skipping repeat onabotA injections despite benefits

Despite reported symptomatic improvement, a significant proportion of patients who receive intra-detrusor onabotulinumtoxinA (onabotA [Botox]) for overactive bladder may not follow up for repeat injections, according to new data presented at the AUA annual meeting in San Francisco.

Studies have shown that onabotA injections are highly efficacious for treating overactive bladder (OAB). However, it appears that many patients who have a good response to initial injections and subjective improvement fail to return for subsequent injections, according to a new retrospective study.

“At our institution, 86% of patients had subjective improvement after the first injection. However, only 54% of those patients with improvement went on to receive a second injection. In addition, only 24% with no improvement went to receive a second injection,” said study investigator Justina Tam, MD, Stony Brook Medicine, Stony Brook, NY, working with Jason Kim, MD, and colleagues.

Read: Ablation of the trigone shows efficacy, safety for OAB

Dr. Tam and her colleagues examined the outcomes of onabotA injections at their own institution and evaluated factors that appear to correlate with continuation of maintenance onabotA injection. They conducted a retrospective chart review on all patients who received onabotA injections from April 2013 to October 2017. For this investigation, the authors compared patients who received one injection to those patients who received more than one injection.

The team identified 175 patients who received at least one onabotA injection. They found that 150 patients (86%) reported subjective symptom improvement after their first injection. Of those who reported improvement, only 81 patients (54%) returned for a second injection. Among those patients who reported no improvement, six patients (24%) also received a second injection. Dr. Tam said in total 87 patients (50%) returned for a second injection.

Next - Dr. Tam: Study results "pretty surprising"“The results from this study were pretty surprising to us,” said Dr. Tam, who presented the research at the meeting.

She said patients who received multiple injections were more likely to have perceived symptomatic improvement (p=.034). In addition, those patients who received multiple injections also were found to be less likely to have side effects following their first injection (p=.027).

“We also found that neurologic disorders may influence the discontinuation of treatment. Studies suggest that patients with neurogenic DO detritional activity have greater improvement with Botox than those who have idiopathic DO activity. So these may play a role,” said Dr. Tam.

Also see: How does onabotA affect brain activity?

She said there were no significant differences found when the authors looked at age, gender, body mass index, or distance to clinic between those who returned for a second injection compared to those who did not.

“Further long-term prospective studies are necessary to evaluate and improve our understanding of why maintenance rates are so low and how these rates can be improved,” said Dr. Tam.

She said because of these study results, her group now utilizes nurse navigators who call patients at 1, 3, and 6 months after their first injection to see if the patients are experiencing any benefits and discuss any adverse side effects they may be experiencing.

“Hopefully, in the future we can see if this improves our rates of maintenance therapy,” said Dr. Tam.