The purpose of this study is to investigate the effect of Lidocaine solution versus placebo (isotonic Sodium Chloride NaCl) disposed inside the urinary bladder as intravesical anesthesia prior to onabotulinum toxin A injections in the treatment of urgency urinary incontinence.

The aim of the study is to investigate if bladder installed Lidocaine solution have an effect on reported pain during BTX-A injections compared to placebo.

The study participants will be recruited from the existing patient populations enrolled in the BTX-A program of the tertiary Urogynaecological Clinic of Herlev University Hospital.

The participants are randomized to:

1. Active drug: Lidocaine Hydrochloride and Sodium hydrogen carbonate
2. Placebo: Sodium Chloride

The study includes 5 study visits:

Visit 1:

• First treatment day
• Randomization
• Registration of pre-treatment pain relief medications: paracetamol, ibuprofen, or other medications. If pre-treatment pain relief is taken before first treatment, same pain relief should be taken before second treatment day (visit 4) in order to reduce bias
• Registration of antibiotic treatment: current antibiotic treatment or long-term prophylactic antibiotic for prevention of recurrent UTI The participant receives the active treatment or placebo, double-blinded
• The participant is asked to grade the intensity of pain according to VAS score immediately after, and when participant has been dressed after the BTX-A injections

Visit 2 (by telephone):

• Phone consultation 1 week after treatment:
• The participant's experience on the procedure on a 5-point ordinal scale: "1- very unsatisfied", "2- unsatisfied", "3- neither unsatisfied or satisfied", "4- satisfied", "5-very satisfied"

Side effects:

• Questions on symptoms of UTI: dysuria, cloudy urine, pollakiuria, nocturia
• Hematuria
• Inability to empty the bladder
• Other symptoms

(Visit 3:)

• The participant contacts the Clinic for next treatment approximately 6-12 months later
• Sponsor or investigator from the Urogynecological Clinic reach out for the participant asking on symptoms of UUI if the participant has not contacted the clinic within 12 months

Visit 4:

• Second treatment day
• The participant receives the opposite treatment, still double-blinded
• Registration of pre-treatment pain relief medications: paracetamol, ibuprofen, or other medications
• Registration of antibiotic treatment: current antibiotic treatment or long-term prophylactic antibiotic for prevention of recurrent UTI
• The participant is asked to grade the intensity of pain according to VAS score immediately after, and when participant has been dressed after the BTX-A injections

Visit 5(by telephone):

• Phone consultation 1 week after treatment:
• The participant's experience on the procedure on a 5-point scale: "1- very unsatisfied", "2- unsatisfied", "3- neither unsatisfied or satisfied", "4- satisfied", "5-very satisfied"

Side effects:

• Questions on symptoms of UTI: dysuria, cloudy urine, pollakiuria nocturia,
• Hematuria
• Inability to empty the bladder
• Other symptoms

Inclusion criteria:

• Female, age ≥18 years
• Admitted to treatment with BTX-A injections at the Urogynecological Clinic at Herlev Hospital due to UUI
• Able to read and understand Danish
• The female accepts to receive BTX-A injections as an outpatient treatment without the option of receiving sedative drugs

Exclusion criteria:

• BTX-A allergy
• Neurological disorder that may affect bladder function (e.g. Multiple sclerosis or spinal cord inju-ry)
• Neurological disorder with neuromuscular transmission failure (i.e. Mystenia Gravis)
• Ongoing UTI or symptoms of UTI prior to treatment, assessed by principal investigator
• Any other bladder pathology at the time of cystoscopy if identified (includes trauma, stones, tu-mor)
• Pregnancy/breastfeeding women

Region Hovedstadens Apotek, Herlev Hospital produces the Lidocaine solution and the matching placebo solution, performs the randomization, and packages the blinded dosing kits with the order of Lidocaine and placebo in a balanced design (50% Lidocaine at the first treatment). Participants will get consecutive randomization numbers, which specify the dosing kit. Neither the participant, the operator, or the healthcare professional interviewing the participant about her pain score know what solution the participant gets administered.