A Phase 4 interventional study of Oxybutynin and Placebo in Ureteropelvic Junction Obstruction and Hypospadias, sponsored by University of Calgary. Not yet recruiting at 1 site in Canada. Open to participants aged Up to 17 Years. Per ClinicalTrials.gov, last updated 2026-11-02.
Sponsored by University of Calgary · Phase 4, Interventional, and Treatment
The goal of this clinical trial is to determine whether giving oxybutynin before urologic reconstruction surgery reduces the amount of opioid pain medication needed in children. Oxybutynin is a medication that helps reduce bladder spasms, which can cause pain and discomfort after surgery.
The main question this study aims to answer is:
Does giving oxybutynin before surgery reduce the amount of opioid pain medication children need during the first 6 hours after surgery?
Researchers will compare oxybutynin with a placebo (a tablet containing no active medication) to see whether oxybutynin reduces opioid use after surgery.
Background
Children undergoing pediatric urologic reconstruction, such as pyeloplasty and hypospadias repair, frequently require urinary drainage via ureteral stent and/or urethral catheter. These tools cause the bladder to contract involuntarily, mediated by muscarinic receptors (i.e., bladder spasms). This leads to increased catheter-related bladder discomfort (CRBD), bladder spasm-associated pain and postoperative opioid use.
Oxybutynin, an antimuscarinic agent, reduces the occurrence of bladder spasms and thus the number and severity of CRBD events and bladder spasm-related pain. This reduction in discomfort/pain may contribute to decreased postoperative opioid use, as suggested by retrospective pediatric data.
Postoperative management of urologic reconstruction surgeries includes PRN administration of opioids and oxybutynin to treat bladder spasm-related discomfort/pain according to institutional practice and prior pediatric urology literature. Oxybutynin takes 1 hour to reach its maximal plasma concentration, during which time significant bladder spasm-related symptoms may already be present when the child is awake. However, opioids such as morphine achieve their maximal effects within 10 minutes. Because opioids are much faster-acting than oxybutynin, this may increase the likelihood of concomitant administration when the child is awake with discomfort/pain. We are therefore considering using oxybutynin preoperatively, rather than just postoperatively PRN, since its plasma concentration will already be maximal or near-maximal upon waking, which may lead to less CRBD, bladder spasm-related pain, and postoperative opioid use.
This study aims to reduce the use of opioids to treat pediatric patients undergoing urologic reconstruction. Opioids carry significant side effects that include nausea, vomiting, respiratory depression, addiction, urinary retention, tolerance, and constipation. Combined with the ongoing opioid epidemic, there is an increased effort among caregivers, including nurses and physicians, to find other means to reduce pain in pediatric patients.
Opioid therapy has also been shown not to be effective in treating bladder spasm-related symptoms (e.g., CRBD, bladder spasm-related pain). As opposed to opioids, oxybutynin directly targets bladder spasm-associated symptoms, and may reduce the severity of side effects. Side effects of oxybutynin include dry mouth, constipation, dizziness, urinary retention, and blurry vision.
Emerging pediatric urology data suggest that a single preoperative dose may reduce early postoperative opioid requirements. However, current evidence is retrospective and non-randomized. There is no high-quality randomized pediatric study evaluating the opioid sparing effects of preoperative oxybutynin administration in pediatric patients undergoing urologic reconstruction.
Study Need, Importance, and Hypothesis
Urologic reconstruction surgeries requiring a stent and/or catheter can be associated with significant CRBD, bladder-spasm associated pain and morbidity. With the growing recognition of the need to decrease opioid medication, our primary objective is to assess whether the administration of preoperative oxybutynin reduces opioid use. We hypothesize that preoperative oxybutynin reduces early postoperative opioid use in children undergoing pyeloplasty or hypospadias repair.
26 studies on the registry are indexed under Multicystic renal dysplasia, bilateral; 9 are open to participants now.
This study's planned enrollment of 200 is above the median of 40 across 20 interventional studies indexed under Multicystic renal dysplasia, bilateral.
Browse Multicystic renal dysplasia, bilateral studies →University of Calgary is the lead sponsor of 703 studies on the registry; 196 are open to participants now.
Of its 10 completed or terminated interventional studies of FDA-regulated products, 2 (20%) have results posted.
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Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
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Participants will receive oxybutynin 0.2 mg/kg (to a maximum dose of 5 mg), orally administered by the day surgery nurse in the day surgery holding area prior to surgery.
Drug: Oxybutynin
Participants will receive a matching placebo tablet, orally administered by the day surgery nurse in the day surgery holding area prior to surgery.
Drug: Placebo
Participants will receive oxybutynin 0.2 mg/kg (to a maximum dose of 5 mg), orally administered by the day surgery nurse in the day surgery holding area prior to surgery.
Participants will receive a matching placebo tablet, orally administered by the day surgery nurse in the day surgery holding area prior to surgery.
Total Cumulative Postoperative Opioid Consumption (MME/kg)
Total cumulative morphine milligram equivalents per kilogram (MME/kg) administered within 6 hours after surgery
Time frame: From the end of surgery through 6 hours postoperatively
Proportion of Participants Receiving Postoperative Opioids
Whether any opioid medication was administered within 6 hours after surgery (yes/no)
Time frame: From the end of surgery through 6 hours postoperatively
Postoperative Pain Scores (NRS/FLACC)
Pain assessed using age-appropriate validated scales: the Numeric Rating Scale (NRS; 0-10) or the Face, Legs, Activity, Cry, Consolability (FLACC; 0-10) scale. Higher scores indicate greater pain.
Time frame: At 15 minutes, 30 minutes, 1 hour, 2 hours, 3 hours, and 6 hours following postoperative removal of the laryngeal mask airway or endotracheal tube
Proportion of Participants Receiving Postoperative Rescue Oxybutynin
Whether oxybutynin was administered as needed (PRN) within 6 hours after surgery (yes/no).
Time frame: From the end of surgery through 6 hours postoperatively
Total Cumulative Postoperative Oxybutynin Consumption (mg/kg)
Total cumulative dose of oxybutynin administered per kilogram of body weight during the first 6 hours after surgery.
Time frame: From the end of surgery through 6 hours postoperatively
Incidence of Adverse Events
Occurrence of adverse events, including dry mouth, flushing, tachycardia, agitation, sedation, and urinary retention.
Time frame: From preoperative study medication administration through postoperative discharge
Plan to share: Undecided
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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Studies of the drug tested here: Oxybutynin
Multicystic renal dysplasia, bilateral →