Intravesical onabotulinumtoxinA injections in patients on antiplatelet and anticoagulation therapy.

Aims: To determine the bleeding risk in patients taking anticoagulants (AC) and antiplatelets (AP) before onabotulinumtoxinA (BoNT-A) injections and improve peri-operative decision making and counseling.

Methods: We performed a retrospective review of patients having intravesical BoNT-A in three teaching hospitals from January 2016 to July 2018. Demographic data, indication for intravesical BoNT-A injection, and side-effects of significant bleeding requiring intervention were recorded.

Results: Five hundred and thirty-two patients had intravesical BoNT-A injections during this time. Sixty-three patients of mean age 69 years (range 19-89) had a total of 114 separate rounds of BoNT-A injections whilst on treatment dose AC/AP therapy. Of the 63, there were 33 males, with 46 having idiopatic detrusor overactivity and 17 with neurogenic detrusor overactivity. Each patient had between 1 and 7 repeat injections during the studied period. AC/AP use across the 114 episodes included; aspirin 44, clopidogrel 37, warfarin 19, and NOAC (novel/non-vitamin K oral anticoagulant) 14. Patients on warfarin who had point of care testing all had international normalized ratio less than 3. BoNT-A dose varied from 100U to 300U-modal dosage was 200U.1/114(0.88%) injection episodes resulted in postinjection hematuria requiring overnight admission. This resolved spontaneously, with an overnight catheter. This patient was on rivaroxaban and had 300U of BoNT-A injected through 20 sites, on a background of previous prostate radiotherapy and self-catheterization.

Conclusions: Continuation of AP/AC therapy during intravesical BoNT-A injection treatment appears to be safe-with a 0.88% rate of spontaneously resolving hematuria.