Alkalinised lidocaine as an anaesthetic before onabotulinumtoxinA injections. a randomised trial

Abstract

ObjectivesTo evaluate the effect of intravesical alkalinised lidocaine as an anaesthetic treatment on procedural pain during intradetrusor onabotulinumtoxinA (BTX‐A) injections for overactive bladder.Patients and MethodsThis single‐centre, randomised, double‐blind, placebo‐controlled two period crossover trial was conducted on women scheduled for BTX‐A injections at our outpatient urogynaecology clinic between September 2022 and May 2024. Patients were randomly assigned (1:1) to receive either alkalinised lidocaine or placebo during the first treatment period. Alkalinised lidocaine solution comprised lidocaine hydrochloride (20 mg/mL, 20 mL), sodium hydrogen carbonate (1 mmoL/mL, 10 mL), and sodium chloride (9 g/L, 10 mL). The matching placebo was sodium chloride (9 g/L, 40 mL). The primary outcome measure was procedural pain rated on a 100‐mm visual analogue scale (VAS). Secondary outcomes included adverse effects such as post‐void residual urine volumes requiring catheterisation, urinary tract infection, haematuria 1 week after treatment, and patient satisfaction measured on a 5‐point scale. During the second treatment period, patients received the alternative intervention.ResultsWe enrolled 50 patients, of which 41 were eligible for per‐protocol analyses. The mean VAS score was significantly lower following intravesical alkalinised lidocaine (mean 21.3 mm, 95% confidence interval [CI] 14.7–27.8 mm) compared to placebo (mean 41.6 mm, 95% CI 35.0–48.1 mm) with a mean difference of −20.3 mm (95% CI −29.2 to −11.5 mm; P < 0.001). Adverse events and patient satisfaction did not significantly differ between the alkalinised lidocaine and placebo treatments (P = 0.825 and P = 0.138, respectively).ConclusionsIntravesical instillation of alkalinised lidocaine before BTX‐A injections significantly reduced VAS pain scores compared to placebo (ClinicalTrials.gov identifier: NCT05415865).