Alkalinized lidocaine versus lidocaine gel as local anesthesia prior to intra-vesical botulinum toxin (BoNTA) injections: A prospective, single center, randomized, double-blind, parallel group trial of efficacy and morbidity.

[AIMS] To assess the efficacy and morbidity of alkalinized lidocaine solution compared to lidocaine gel for intra-vesical anesthesia during botulinum toxin (BoNTA) injections in a statistically powered, prospective, parallel group, double-blind randomized controlled trial.

[METHODS] Fifty-four patients of either sex were randomized to receive either alkalinized lidocaine (AL) solution (10 ml 8.4% sodium bicarbonate + 20 ml 2% lidocaine solution + 22 ml sterile Aquagel®) or lidocaine gel (LG) (22 ml standard 2% lidocaine gel Instillagel® + 30 ml 0.9% normal saline solution). Primary outcome was average pain (assessed by 100 mm visual analog score) felt during intra-vesical BoNTA injections performed at least 20 min after instillation. Secondary outcome was the rate of adverse events.

[RESULTS] Of 60 randomized patients 54 received the allocated intervention and were analyzed. Mean pain score in the AL group was 17.11 mm (95%CI 8.65-25.57 mm) and in the LG group was 19.53 mm (95%CI 13.03-26.03mm) with no significant difference between the groups. Cost of interventional medication in the AL group was almost double that of the LG group. No adverse events were attributable to local anesthetic instillation in either group.

[CONCLUSIONS] Alkalinized lidocaine solution is not superior to lidocaine gel for anesthesia during intra-vesical BoNTA injections, and the higher cost precludes its use over lidocaine gel at our centre. We have used the results of this study to adapt our local protocol for BoNTA injections and continue to use lidocaine gel as the local anesthetic of choice. Neurourol. Urodynam. 35:522-527, 2016. © 2015 Wiley Periodicals, Inc.