A Randomized, Double-Blind, Placebo-Controlled Trial of Anrikefon for Postoperative Analgesia After Percutaneous Nephrolithotomy (ARK-PCNL)

A Single-Center, Randomized, Double-Blind, Placebo-Controlled Study of Anrikefon for Perioperative Analgesia in Patients Undergoing Percutaneous Nephrolithotomy (PCNL)

This study evaluates whether a single dose of anrikefon, given intravenously shortly before the end of kidney stone removal surgery (PCNL), can reduce opioid-related side effects such as nausea, vomiting, itching, oversedation, and breathing problems in the first 24 hours after surgery. All participants receive the same standard pain control regimen (flurbiprofen axetil plus a sufentanil patient-controlled pump). In addition, half receive anrikefon and half receive a placebo (saline), decided by random allocation, with neither patients nor doctors knowing who receives which. A total of 160 adults (18-75 years) undergoing elective PCNL at Beijing Tsinghua Changgung Hospital will take part. Pain scores, opioid use, recovery, satisfaction, kidney function and side effects will be followed for up to 3 days after surgery.

Study Overview

• Status: Not yet recruiting
• Conditions: Nephrolithiasis; Postoperative Pain
• Intervention / Treatment: Drug: Anrikefon; Drug: 0.9% Sodium Chloride Injection as Placebo

• Study Type: Interventional
• Enrollment (Estimated): 160
• Phase: Phase 4

Contacts and Locations

• Study Contact: Name: Haotian Wu, MD; Phone Number: +86 17600809297; Email: tatabox@163.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Age 18-75 years, either sex
• Scheduled elective unilateral percutaneous nephrolithotomy (PCNL) under general anesthesia (stone diameter >2 cm, meeting PCNL indications)
• ASA classification I-III
• Body mass index (BMI) 18-35 kg/m2
• Preoperative estimated glomerular filtration rate (eGFR) >=60 mL/min/1.73 m2
• Resting pain NRS score <=2 within 24 h before surgery
• Voluntary participation with written informed consent signed by the patient
• Ability to cooperate with postoperative pain assessment, follow-up and examinations

Exclusion Criteria:

• Allergy to anrikefon, sufentanil, flurbiprofen axetil or their excipients
• Use of opioids, NSAIDs, glucocorticoids or other analgesics within 7 days before surgery
• Renal dysfunction (eGFR <60 mL/min/1.73 m2) or severe hepatic dysfunction (ALT/AST >3 times upper limit of normal)
• Severe cardiovascular or respiratory disease (e.g., COPD, respiratory failure)
• History of gastrointestinal ulcer or bleeding, or coagulation disorders
• Pregnant or lactating women
• History of cognitive impairment or drug/alcohol dependence
• Concurrent participation in other clinical trials

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Anrikefon; Anrikefon 0.1 mg IV (diluted to 5 mL) 15-30 min before the end of surgery, added to standard multimodal analgesia: flurbiprofen axetil 50 mg IV plus sufentanil PCIA.	Drug: Anrikefon; Single IV dose of anrikefon 0.1 mg diluted to 5 mL with 0.9% saline, administered 15-30 min before the end of surgery.
Placebo Comparator: Placebo; 0.9% saline 5 mL IV 15-30 min before the end of surgery, identical in appearance, added to the same standard multimodal analgesia: flurbiprofen axetil 50 mg IV plus sufentanil PCIA.	Drug: 0.9% Sodium Chloride Injection as Placebo; 5 mL IV, administered 15-30 min before the end of surgery; identical in appearance to anrikefon; used as placebo comparator.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Incidence of composite opioid-related adverse events (ORAEs) within 24 h after surgery	Postoperative hours 0-6, 6-12, and 12-24; composite endpoint assessed over the 24-hour period immediately after surgery

Secondary Outcome Measures

Outcome Measure	Time Frame
Cumulative sufentanil consumption	Postoperative hours 0-24 and 24-48
Pain intensity by numeric rating scale (NRS), 0-10 score	Postoperative hours 0.5, 1, 2, 4, 8, 12, and 24
Total and effective patient-controlled analgesia (PCA) bolus counts (number)	Within the first 24 hours after surgery
PCA effective bolus ratio (%)	Within the first 24 hours after surgery
Rate of patients requiring rescue analgesia (%)	Within the first 24 hours after surgery
Number of rescue analgesic doses (count)	Within the first 24 hours after surgery
Time to first flatus (hours)	From surgery until the date of first documented flatus, assessed up to 7 days after surgery
Time to first ambulation (hours)	From surgery until the date of first ambulation, assessed up to 7 days after surgery
Duration of postoperative hospital stay (days)	From surgery until the date of hospital discharge, assessed up to 7 days after surgery
Analgesia satisfaction score (0-10)	At postoperative hour 24
Serum creatinine and blood urea nitrogen (mg/dL)	Baseline (preoperative) and at postoperative hours 24, 48, and 72
Estimated glomerular filtration rate (eGFR, mL/min/1.73 m²)	Baseline (preoperative) and at postoperative hours 24, 48, and 72
Incidence of acute kidney injury per KDIGO criteria (%)	Baseline (preoperative) through postoperative hour 72
Incidence of adverse events (%)	From study drug administration through postoperative hour 72
Area under the curve of NRS scores over 24 hours (AUC₀-₂₄ₕ, score-hours)	Postoperative hours 0-24

Collaborators and Investigators

• Sponsor: Beijing Tsinghua Chang Gung Hospital

Study record dates

Study Major Dates

• Study Start (Estimated): October 12, 2026
• Primary Completion (Estimated): July 1, 2029
• Study Completion (Estimated): December 30, 2029

Study Registration Dates

• First Submitted: September 10, 2026
• First Submitted That Met QC Criteria: September 16, 2026
• First Posted (Actual): September 17, 2026

Study Record Updates

• Last Update Posted (Actual): September 17, 2026
• Last Update Submitted That Met QC Criteria: September 16, 2026
• Last Verified: September 1, 2026

More Information

Terms related to this study

• Keywords: Perioperative analgesia; Multimodal analgesia; PCNL; Percutaneous Nephrolithotomy; Anrikefon; Opioid-related adverse events; Peripheral kappa opioid receptor agonist
• Additional Relevant MeSH Terms: Urogenital Diseases; Pain; Neurologic Manifestations; Postoperative Complications; Pathologic Processes; Male Urogenital Diseases; Kidney Diseases; Urologic Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Urolithiasis; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Pain, Postoperative; Nephrolithiasis; Inorganic Chemicals; Chlorine Compounds; Sodium Compounds; Chlorides; Hydrochloric Acid; Sodium Chloride
• Other Study ID Numbers: 27024-0-01 (Other Grant/Funding Number: Beijing Tsinghua Changgung Hospital Medical Ethics Committee)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Individual participant data will not be shared due to patient privacy considerations; de-identified aggregate results will be published in peer-reviewed journals.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No