Efficacy and Safety of Anrikefon for Postoperative Analgesia in Ophthalmic Surgery

March 31, 2026 updated by: Xiaoliang Gan, Zhongshan Ophthalmic Center, Sun Yat-sen University

Efficacy and Safety of Anrikefon for Postoperative Analgesia in Ophthalmic Surgery: A Multicenter, Randomized, Parallel-Control, Non-Inferiority Trial

The goal of this clinical trial is to learn if Anrikefon works as well as nalbuphine to control postoperative pain in adults undergoing ophthalmic surgery under general anesthesia. It will also learn about the safety and recovery outcomes of using Anrikefon.

The main questions it aims to answer are:

  • Does Anrikefon provide pain relief that is not inferior to nalbuphine after ophthalmic surgery?
  • Does Anrikefon cause fewer central side effects, such as sedation or dizziness, compared with nalbuphine?
  • Does Anrikefon help patients recover and get discharged faster after day-surgery procedures? Researchers will compare Anrikefon to nalbuphine to see if Anrikefon can offer effective and safer perioperative analgesia for ophthalmic day-surgery patients.

Participants will:

  • Receive either an intravenous dose of Anrikefon or nalbuphine during surgery.
  • Be monitored for pain scores, side effects, and recovery parameters after surgery.
  • Complete follow-up assessments.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

204

Phase

  • Phase 4

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

  • China
      • Shanghai, China, 200031
        • Not yet recruiting
        • Eye & ENT Hospital of Fudan University
        • Contact:
        • Contact:
    • Guangdong
      • Guangzhou, Guangdong, China, 510060
        • Recruiting
        • Zhongshan Ophthalmic Center, Sun Yat-sen University
        • Contact:
        • Contact:
    • Yunnan
      • Kunming, Yunnan, China, 650000
        • Not yet recruiting
        • The Affiliated Hospital of Yunnan University
        • Contact:
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Scheduled for ophthalmic surgery under general anesthesia.
  • Aged 18 to 70 years.
  • With American Society of Anesthesiologists (ASA) physical status I to III.
  • Body mass index (BMI) between 18 and 30 kg/m²
  • Agree to participate in the trial and provide written informed consent.

Exclusion Criteria:

  • History of cardiovascular or cerebrovascular events within the past 6 months, including unstable angina, ischemic myocardial infarction, or heart failure; or current presence of uncontrolled hypertension (>180/110 mmHg), aneurysm, or severe cardiac arrhythmia.
  • Severe respiratory diseases such as pulmonary fibrosis, severe pulmonary abscess, cor pulmonale, or advanced chronic obstructive pulmonary disease (COPD).
  • Significant neurological disorders such as brain injury or seizures, as well as severe psychiatric illnesses.
  • Known allergy to kappa opioid receptor agonists or to general anesthetic agents used in this study.
  • Current peptic ulcer disease, gastrointestinal bleeding, or known hypersensitivity to nonsteroidal anti-inflammatory drugs (NSAIDs), such as flurbiprofen axetil or paracetamol.
  • Prior use of opioid or non-opioid analgesics, with the last administration occurring within five half-life periods of the drug.
  • Continuous use of opioid analgesics for more than 10 days within the 3 months prior to screening.
  • Use of drugs with unknown half-life periods that may affect analgesic efficacy within 14 days before randomization.
  • History of major surgery within the past 3 months that may interfere with postoperative pain assessment.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

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

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: The Anrikefon Group
Intravenous injection of Anrikefon 1 μg/kg will be administered 15 minutes before the end of surgery
Drug: Anrikefon
Anrikefon is a novel peripherally KOR agonist independently developed in China. In this study, anrikefon will be administered intravenously at a dose of 1 μg/kg, 15 minutes before the end of surgery.
Active Comparator: The Nalbuphine Group
Intravenous injection of nalbuphine 0.1 mg/kg will be administered 15 minutes before the end of surgery
Drug: Nalbuphine
Nalbuphine is a traditional central KOR agonist with mixed μ-opioid receptor antagonist activity. In this study, nalbuphine will be administered intravenously at a dose of 0.1 mg/kg, 15 minutes before the end of surgery.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Cumulative pain severity at rest during the first 6 hours after surgery, measured with the Numeric Rating Scale (0-10, higher scores = worse pain)
Time Frame: In the PACU and at 1 , 2 , 4 and 6 hours after surgery
Pain intensity at rest is recorded with the Numeric Rating Scale (NRS: 0 = no pain, 10 = worst possible pain). The area under the curve (AUC) for these scores will be calculated with the trapezoidal rule, using assessments performed in the PACU and at 1 , 2 , 4 and 6 hours post-operatively. A higher AUC indicates greater cumulative pain over the 6-hour period.
In the PACU and at 1 , 2 , 4 and 6 hours after surgery

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Pain severity at rest and during eye movement, measured with the Numeric Rating Scale (0-10, higher scores = worse pain)
Time Frame: In the PACU and at 1, 2, 4, 6, 12 and 24 hours, as well as 1 week and 1 month postoperatively
Participants rate their pain intensity at rest and again during voluntary eye movement using the Numeric Rating Scale (NRS: 0 = no pain, 10 = worst possible pain). Assessments are performed in the PACU and at 1, 2, 4, 6, 12, 24 hours, 1 week, and 1 month post-operatively. Higher scores indicate greater pain.
In the PACU and at 1, 2, 4, 6, 12 and 24 hours, as well as 1 week and 1 month postoperatively
Cumulative pain severity during eye movement (0-6 hours) and at rest/during eye movement (0-12 hours and 0-24 hours), measured with the Numeric Rating Scale
Time Frame: In the PACU and at 1, 2, 4, 6, 12, and 24 hours postoperatively
The area under the curve (AUC) is computed with the trapezoidal rule, multiplying the average Numeric Rating Scale within each interval by its duration and summing the products; a higher AUC indicates greater cumulative pain.
In the PACU and at 1, 2, 4, 6, 12, and 24 hours postoperatively
Cumulative consumption of rescue analgesics (flurbiprofen axetil in the PACU and paracetamol after discharge from the PACU) within 6, 12, and 24 hours postoperatively, as well as the time to first use
Time Frame: At 6, 12, and 24 hours postoperatively
In-hospital, participants with resting NRS ≥4 will receive intravenous flurbiprofen axetil 1 mg/kg. Additional doses can be given if ≥3 hours have passed since the previous flurbiprofen dose and ≥1 hour since the last study drug. Breakthrough pain (NRS ≥7) may be treated immediately. Out-of-hospital, participants with resting NRS ≥4 will receive paracetamol 500 mg per dose, up to 2 g per day.
At 6, 12, and 24 hours postoperatively
Percentage of patients not requiring rescue analgesics
Time Frame: At 6, 12, and 24 hours postoperatively
During the 6-, 12-, and 24-hour postoperative periods, each patient's use of rescue analgesics (flurbiprofen axetil or paracetamol) is recorded. Patients not receiving rescue analgesics are classified as 'not used,' and the percentage is calculated for each group to evaluate postoperative analgesia adequacy.
At 6, 12, and 24 hours postoperatively
Satisfaction score of analgesia within 24 hours postoperatively
Time Frame: Within 24 hours postoperatively
A trained study assistant assessed satisfaction score of analgesia at rest using a 0 to 10 NRS scale, where 0 indicates 'completely dissatisfied' and 10 indicates 'completely satisfied.'
Within 24 hours postoperatively
Emergence time
Time Frame: Through surgery completion, an average of 1 hour.
Emergence time is defined as the interval from stopping anesthetics to eye opening or following simple commands.
Through surgery completion, an average of 1 hour.
PACU stay time
Time Frame: Through surgery completion, an average of 2 hours.
PACU stay time is defined as the duration from arrival in PACU to the time of a modified Aldrete score of 9 or 10.
Through surgery completion, an average of 2 hours.
Time to first ambulation
Time Frame: Through surgery completion, an average of 24 hours.
Time to first ambulation is defined as the interval from the completion of surgery to the patient's first episode of spontaneous mobilization (i.e., getting out of bed and initiating independent movement).
Through surgery completion, an average of 24 hours.
Postoperative hospital stay
Time Frame: Through surgery completion, an average of 24 hours
Postoperative hospital stay (or in-hospital stay for day-surgery patients) is defined as the interval from the completion of surgery to formal discharge from the hospital.
Through surgery completion, an average of 24 hours
Incidence of postoperative complications in the PACU and within 24 hours postoperatively
Time Frame: In the PACU and within 24 hours postoperatively
All assessments of adverse events and medication records will be conducted under double-blind conditions, with evaluators blinded to participant group assignment. The incidence of adverse events will be calculated based on the total number of enrolled participants in each group.
In the PACU and within 24 hours postoperatively
Postoperative 24-hour recovery quality assessed using the 15-item Quality of Recovery questionnaire (QoR-15)
Time Frame: At 24 hours postoperatively
Postoperative recovery was assessed using the QoR-15 questionnaire.
At 24 hours postoperatively
Intraocular pressure (IOP) [mmHg]
Time Frame: At 24 hours, 1 week, and 1 month postoperatively
Measured with non-contact tonometer; higher values indicate elevated IOP.
At 24 hours, 1 week, and 1 month postoperatively
Orbital pressure [digital palpation grade]
Time Frame: At 24 hours, 1 week, and 1 month postoperatively
Graded by single examiner via digital palpation.
At 24 hours, 1 week, and 1 month postoperatively
Uncorrected visual acuity (UCVA) [LogMAR]
Time Frame: At 24 hours, 1 week, and 1 month postoperatively
Assessed with standard LogMAR chart; lower LogMAR indicates better acuity.
At 24 hours, 1 week, and 1 month postoperatively
Best-corrected visual acuity (BCVA) [LogMAR]
Time Frame: At 24 hours, 1 week, and 1 month postoperatively
Assessed with standard LogMAR chart after refraction; lower LogMAR indicates better acuity.
At 24 hours, 1 week, and 1 month postoperatively

Other Outcome Measures

Outcome Measure
Measure Description
Time Frame
Mechanical pain threshold of the operative eye at 2 and 24 hours postoperatively
Time Frame: At 2 and 24 hours postoperatively
Quantitative assessment around the periocular area of the operative eye using electronic Von Frey test.
At 2 and 24 hours postoperatively

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Zhongshan Ophthalmic Center, Sun Yat-sen University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

January 22, 2026

Primary Completion (Estimated)

December 31, 2027

Study Completion (Estimated)

December 31, 2027

Study Registration Dates

First Submitted

November 17, 2025

First Submitted That Met QC Criteria

December 4, 2025

First Posted (Actual)

December 8, 2025

Study Record Updates

Last Update Posted (Actual)

April 1, 2026

Last Update Submitted That Met QC Criteria

March 31, 2026

Last Verified

March 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • IIT2025115

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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