Laparoscopic SurgeryPhase 4NCT07246785
Anrikefon-based Patient-controlled Intravenous Analgesia After Laparoscopic Surgery
A Phase 4 study testing High-dose anrikefon, Medium-dose anrikefon and Low-dose anrikefon in people with Laparoscopic Surgery and Visceral Pain, Postoperative, run by Peking University First Hospital at 1 site in China.
Trial summary
Visceral pain following laparoscopic surgery is frequently underestimated, yet it is associated with a range of adverse outcomes. Effective visceral pain management should constitute an essential component of postoperative analgesic strategies following laparoscopic procedures. Read more about this study
- Who is it for?
- Ages 18 to 74 years
- Conditions the study is for
- Laparoscopic Surgery, Visceral Pain, Postoperative, Anrikefon
- What is being tested?
- High-dose anrikefon, Medium-dose anrikefon and Low-dose anrikefon
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 13 participants
- Where
- 1 siteChina
- Study dates
- 25 Dec 2025to 11 Mar 2026
- Phase
- Phase 4
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 74 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Aged ≥ 18 years but < 75 years;
- Scheduled to undergo elective laparoscopic gastrointestinal surgery with an expected duration of ≥1 hour;
- The incisional pain can be covered by the transversus abdominis plane block or rectus sheath block; yet patients still require postoperative patient-controlled intravenous analgesia.
Who cannot join
- Presence of preoperative cognitive impairment (Mini-Mental State Examination [MMSE] score < 27), or inability to communicate due to language barrier;
- Body mass index (BMI) > 30 kg/m² or < 18 kg/m²;
- Presence of poorly controlled or untreated comorbidities, including but not limited to the following: hypertension characterized by a resting systolic blood pressure (SBP) > 180 mmHg and/or diastolic blood pressure (DBP) > 110 mmHg, coronary artery disease with unstable angina or myocardial infarction within 6 months, heart failure rated as New York Heart Association classification ≥ III, severe chronic obstructive pulmonary disease (or in a state of acute exacerbation), severe hepatic insufficiency (Child-Pugh grade C), severe renal insufficiency (estimated glomerular filtration rate < 30 ml/min/1.73m²), or American Society of Anesthesiologists (ASA) physical status classification ≥ IV;
- Continuous use of opioid analgesics for more than 10 days for any reason, or alcohol abuse (average daily intake of pure alcohol > 36 g) within 3 months before screening;
- Preoperative use of opioid or non-opioid analgesics with the interval between the last administration and randomization shorter than five half-lives of the drug or the duration of drug action (whichever is longer);
- Known allergies or contraindications to opiates or other medications that may be used in this study, such as anesthetics, antiemetics, and nonsteroidal anti-inflammatory drugs (NSAIDs);
- Anticipated need for postoperative mechanical ventilation；
- Other conditions that are considered unsuitable for study participation.
Trial locations and contacts
1 site in 1 country.
China1 site
Peking University First Hospital
Beijing, Beijing Municipality, 100034
About this study
Official title: Efficacy of Anrikefon-based Patient-controlled Intravenous Analgesia for Pain Management After Laparoscopic Surgery: a Randomized, Double-blind, Active-controlled Pilot Trial
Visceral pain following laparoscopic surgery is frequently underestimated, yet it is associated with a range of adverse outcomes. Effective visceral pain management should constitute an essential component of postoperative analgesic strategies following laparoscopic procedures. However, conventional analgesic agents, including μ-opioid receptor agonists, lack specificity for visceral pain. Anrikefon, a novel selective peripheral κ-opioid receptor agonist, demonstrates unique efficacy in alleviating visceral pain with a favorable safety profile. Preliminary studies showed that a single intravenous dose of anrikefon effectively alleviates postoperative pain after abdominal surgery with a low risk of adverse effects. The investigators hypothesize that an appropriate dosing regimen of anrikefon administered via patient-controlled intravenous analgesia (PCIA) pump, as part of a multimodal analgesic strategy, can specifically target and alleviate visceral pain after laparoscopic surgery, thereby achieving comprehensive postoperative analgesia.
Read the detailed description
Approximately 50% to 90% of patients undergoing abdominal surgery experience moderate or severe acute postoperative pain, which primarily comprises somatic, visceral, and inflammatory pain components, with peak intensity typically occurring within the first 24 to 72 hours after surgery. Inadequate management of acute postoperative pain not only increases patients' suffering and impairs their sleep quality, but also increases the risk of postoperative complications, delays postsurgical recovery, prolongs hospital stay, elevates healthcare costs, and even contributes to the development of chronic neuropathic pain.
With advances in minimally invasive techniques and the widespread application of laparoscopic surgery, surgical incisions on the body surface have been significantly reduced, leading to diminished somatic pain. However, the intra-abdominal visceral injury is not necessarily reduced and can even be more substantial in this context, leading to prominent postoperative visceral pain that perioperative clinicians often underestimate. Consequently, effective management of visceral pain should be an essential component of postoperative analgesic strategies following laparoscopic procedures.
Opioids, renowned for their potent analgesic efficacy, serve as the cornerstone of perioperative acute pain management and constitute a critical element of multimodal analgesic regimens. Nevertheless, due to the sparse expression of μ-opioid receptors in visceral pain pathways and their weak modulation of visceral pain afferent signaling, the conventional μ-opioid receptor agonists, such as morphine, exhibit limited effectiveness against visceral pain. Anrikefon is a novel selective peripheral κ-opioid receptor agonist. Due to the high expression levels of κ-opioid receptors within visceral pain pathways, anrikefon exerts an unique therapeutic effect in alleviating visceral pain with a relatively low risk of adverse effects.
Preliminary studies indicate that a single intravenous dose of Anrikefon effectively alleviates pain after abdominal surgery with a low incidence of adverse effects. Additional evidence suggests that patient-controlled intravenous administration of anrikefon provides effective analgesia after orthopedic surgery without respiratory depression or other severe adverse effects. However, the appropriate dosing regimen of anrikefon for patient-controlled intravenous analgesia (PCIA) following laparoscopic surgery remains to be established.
The investigators hypothesize that administering appropriate doses of anrikefon via PCIA pump, as part of a multimodal analgesic regimen that comprises regional nerve blocks targeting somatic pain and nonsteroidal anti-inflammatory drugs (NSAIDs) targeting inflammatory pain, will specifically and effectively alleviate visceral pain following laparoscopic surgery. This pilot trial aims to explore the preliminary efficacy and optimal dosing regimen of anrikefon administered via PCIA after laparoscopic surgery, assess the feasibility of conducting a larger-scale randomized controlled trial, and provide essential parameters for sample size estimation in subsequent investigations.
- Conditions
- Laparoscopic Surgery, Visceral Pain, Postoperative, Anrikefon, Patient-controlled Intravenous Analgesia
- Being tested
- High-dose anrikefon, Medium-dose anrikefon, Low-dose anrikefon, Morphine
- Keywords
- Laparoscopic surgery, Visceral pain, Postoperative, Anrikefon, Patient-controlled intravenous analgesia
- Medical subject headings
- Visceral Pain
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
High-dose anrikefonDrug
Also called High-dose anrikefon-based patient-controlled analgesia
Patients in this group receive postoperative patient-controlled intravenous analgesia for 48 hours. The formula comprises anrikefon (10 μg/ml), diluted with normal saline to 100 ml. The analgesic pump is set to deliver an initial loading dose of 8 ml, followed by patient-controlled boluses of 4 ml with a 10-minute lockout interval and no background infusion.
Medium-dose anrikefonDrug
Also called Medium-dose anrikefon-based patient-controlled analgesia
Patients in this group receive postoperative patient-controlled intravenous analgesia for 48 hours. The formula comprises anrikefon (7.5 μg/ml), diluted with normal saline to 100 ml. The analgesic pump is set to deliver an initial loading dose of 8 ml, followed by patient-controlled boluses of 4 ml with a 10-minute lockout interval and no background infusion.
Low-dose anrikefonDrug
Also called Low-dose anrikefon-based patient-controlled analgesia
Patients in this group receive postoperative patient-controlled intravenous analgesia for 48 hours. The formula comprises anrikefon (5 μg/ml), diluted with normal saline to 100 ml. The analgesic pump is set to deliver an initial loading dose of 8 ml, followed by patient-controlled boluses of 4 ml with a 10-minute lockout interval and no background infusion.
MorphineDrug
Also called Morphine-based patient-controlled analgesia
Patients in this group receive postoperative patient-controlled intravenous analgesia for 48 hours. The formula comprises morphine (0.5 mg/ml), diluted with normal saline to 100 ml. The analgesic pump is set to deliver an initial loading dose of 8 ml, followed by patient-controlled boluses of 4 ml with a 10-minute lockout interval and no background infusion.
| Study group | Role | What they receive |
|---|---|---|
| High-dose anrikefon group | Experimental | Postoperative patient-controlled intravenous analgesia is established with anrikefon 1000 μg, diluted with normal saline to 100 ml, and programmed to administer an initial loading dose of 8 ml, followed by 4-ml boluses with a lockout interval of 10 minutes and no continuous background infusion. Receives: Drug: High-dose anrikefon |
| Medium-dose anrikefon group | Experimental | Postoperative patient-controlled intravenous analgesia is established with anrikefon 750 μg, diluted with normal saline to 100 ml, and programmed to administer an initial loading dose of 8 ml, followed by 4-ml boluses with a lockout interval of 10 minutes and no continuous background infusion. Receives: Drug: Medium-dose anrikefon |
| Low-dose anrikefon group | Experimental | Postoperative patient-controlled intravenous analgesia is established with anrikefon 500 μg, diluted with normal saline to 100 ml, and programmed to administer an initial loading dose of 8 ml, followed by 4-ml boluses with a lockout interval of 10 minutes and no continuous background infusion. Receives: Drug: Low-dose anrikefon |
| Morphine group | Active comparator | Postoperative patient-controlled intravenous analgesia is established with morphine 50 mg, diluted with normal saline to 100 ml, and programmed to administer an initial loading dose of 8 ml, followed by 4-ml boluses with a lockout interval of 10 minutes and no continuous background infusion. Receives: Drug: Morphine |
What is being measured
The primary outcome is the main question the study is designed to answer.
Time-weighted sum of pain intensity difference (SPID) of movement-evoked visceral pain within 48 hours
Time-weighted SPID is defined as the cumulative sum of the product obtained by multiplying the pain intensity difference at each time point (calculated by subtracting the baseline pain intensity score from the current pain intensity score) by the time difference (the current time point minus the previous time point). Movement-evoked visceral pain intensity will be assessed before intervention and at 0.5, 1, 2, 6, 12, 24, 36, and 48 hours after intervention using an 11-point Numeric Rating Scale (0 = no pain, 10 = the worst pain).
Measured: Within 48 hours after intervention.
Secondary outcomes (5)
Time-weighted SPID of visceral pain at rest within 48 hours
Time-weighted SPID is defined as the cumulative sum of the product obtained by multiplying the pain intensity difference at each time point (calculated by subtracting the baseline pain intensity score from the current pain intensity score) by the time difference (the current time point minus the previous time point). The intensity of visceral pain at rest will be assessed before intervention and at 0.5, 1, 2, 6, 12, 24, 36, and 48 hours after intervention using an 11-point Numeric Rating Scale (0 = no pain, 10 = the worst pain).
Measured: Within 48 hours after intervention.
Time-weighted SPID of movement-evoked somatic pain within 48 hours
Time-weighted SPID is defined as the cumulative sum of the product obtained by multiplying the pain intensity difference at each time point (calculated by subtracting the baseline pain intensity score from the current pain intensity score) by the time difference (the current time point minus the previous time point). Movement-evoked somatic pain intensity will be assessed before intervention and at 0.5, 1, 2, 6, 12, 24, 36, and 48 hours after intervention using an 11-point Numeric Rating Scale (0 = no pain, 10 = the worst pain).
Measured: Within 48 hours after intervention.
Time-weighted SPID of somatic pain at rest within 48 hours
Time-weighted SPID is defined as the cumulative sum of the product obtained by multiplying the pain intensity difference at each time point (calculated by subtracting the baseline pain intensity score from the current pain intensity score) by the time difference (the current time point minus the previous time point). The intensity of somatic pain at rest will be assessed before intervention and at 0.5, 1, 2, 6, 12, 24, 36, and 48 hours after intervention using an 11-point Numeric Rating Scale (0 = no pain, 10 = the worst pain).
Measured: Within 48 hours after intervention.
Time-weighted SPID of movement-evoked overall pain within 48 hours
Time-weighted SPID is defined as the cumulative sum of the product obtained by multiplying the pain intensity difference at each time point (calculated by subtracting the baseline pain intensity score from the current pain intensity score) by the time difference (the current time point minus the previous time point). Movement-evoked overall pain intensity will be assessed before intervention and at 0.5, 1, 2, 6, 12, 24, 36, and 48 hours after intervention using an 11-point Numeric Rating Scale (0 = no pain, 10 = the worst pain).
Measured: Within 48 hours after intervention.
Time-weighted SPID of overall pain at rest within 48 hours
Time-weighted SPID is defined as the cumulative sum of the product obtained by multiplying the pain intensity difference at each time point (calculated by subtracting the baseline pain intensity score from the current pain intensity score) by the time difference (the current time point minus the previous time point). The intensity of overall pain at rest will be assessed before intervention and at 0.5, 1, 2, 6, 12, 24, 36, and 48 hours after intervention using an 11-point Numeric Rating Scale (0 = no pain, 10 = the worst pain).
Measured: Within 48 hours after intervention.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted24 Nov 2025
- Study start25 Dec 2025
- Primary completion11 Feb 2026
- Study completion11 Mar 2026
Why it stopped: The study was terminated due to substantial protocol amendments involving changes in the target population and primary endpoint, rendering previously collected data incompatible with the revised study objective.
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (23)Papers the sponsor has linked to this study.
- Other trials for Laparoscopic SurgeryStudies of the same condition, open and under way.
- More trials run by Peking University First HospitalThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 4
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 13 participants (actual)
Sponsor and investigators
- Lead sponsor
- Peking University First Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Dong-Xin Wang, Peking University First Hospital
- Investigators
- Dong-Xin Wang, MD, PhD, Principal investigator, Peking University First Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07246785
- Sponsor's protocol ID
- 2025R0444
- Status last verified
- Apr 2026
- First submitted
- 14 Nov 2025
- Last updated
- 9 Apr 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Liu Y, Xiao S, Yang H, Lv X, Hou A, Ma Y, Jiang Y, Duan C, Mi W; CAPOPS Group. Postoperative pain-related outcomes and perioperative pain management in China: a population-based study. Lancet Reg Health West Pac. 2023 Jun 10;39:100822. doi: 10.1016/j.lanwpc.2023.100822. eCollection 2023 Oct.
PubMed 37927993Armstrong RA, Fayaz A, Manning GLP, Moonesinghe SR; Peri-operative Quality Improvement Programme (PQIP) delivery team; Oliver CM; PQIP collaborative. Predicting severe pain after major surgery: a secondary analysis of the Peri-operative Quality Improvement Programme (PQIP) dataset. Anaesthesia. 2023 Jul;78(7):840-852. doi: 10.1111/anae.15984. Epub 2023 Mar 2.
PubMed 36862937Glare P, Aubrey KR, Myles PS. Transition from acute to chronic pain after surgery. Lancet. 2019 Apr 13;393(10180):1537-1546. doi: 10.1016/S0140-6736(19)30352-6.
PubMed 30983589Wildbrett P, Oh A, Naundorf D, Volk T, Jacobi CA. Impact of laparoscopic gases on peritoneal microenvironment and essential parameters of cell function. Surg Endosc. 2003 Jan;17(1):78-82. doi: 10.1007/s00464-002-9015-3. Epub 2002 Sep 30.
PubMed 12360379Papparella A, Noviello C, Romano M, Parmeggiani P, Paciello O, Papparella S. Local and systemic impact of pneumoperitoneum on prepuberal rats. Pediatr Surg Int. 2007 May;23(5):453-7. doi: 10.1007/s00383-006-1860-z.
PubMed 17333216Hatipoglu S, Akbulut S, Hatipoglu F, Abdullayev R. Effect of laparoscopic abdominal surgery on splanchnic circulation: historical developments. World J Gastroenterol. 2014 Dec 28;20(48):18165-76. doi: 10.3748/wjg.v20.i48.18165.
PubMed 25561784de Lacy FB, Taura P, Arroyave MC, Trepanier JS, Rios J, Bravo R, Ibarzabal A, Pena R, Deulofeu R, Lacy AM. Impact of pneumoperitoneum on intra-abdominal microcirculation blood flow: an experimental randomized controlled study of two insufflator models during transanal total mesorectal excision : An experimental randomized multi-arm trial with parallel treatment design. Surg Endosc. 2020 Oct;34(10):4494-4503. doi: 10.1007/s00464-019-07236-5. Epub 2019 Nov 7.
PubMed 31701284Cheong JY, Keshava A, Witting P, Young CJ. Effects of Intraoperative Insufflation With Warmed, Humidified CO2 during Abdominal Surgery: A Review. Ann Coloproctol. 2018 Jun;34(3):125-137. doi: 10.3393/ac.2017.09.26. Epub 2018 Jun 30.
PubMed 29991201Sikandar S, Dickenson AH. Visceral pain: the ins and outs, the ups and downs. Curr Opin Support Palliat Care. 2012 Mar;6(1):17-26. doi: 10.1097/SPC.0b013e32834f6ec9.
PubMed 22246042Kendall GP. Visceral pain. Br J Surg. 1985 Sep;72 Suppl:S4-5. doi: 10.1002/bjs.1800721304. No abstract available.
PubMed 3899257Golzari SE, Nader ND, Mahmoodpoor A. Underlying Mechanisms of Postoperative Pain After Laparoscopic Surgery. JAMA Surg. 2016 Mar;151(3):295-6. doi: 10.1001/jamasurg.2015.3934. No abstract available.
PubMed 26535957Choi JB, Kang K, Song MK, Seok S, Kim YH, Kim JE. Pain Characteristics after Total Laparoscopic Hysterectomy. Int J Med Sci. 2016 Jul 5;13(8):562-8. doi: 10.7150/ijms.15875. eCollection 2016.
PubMed 27499688Blichfeldt-Eckhardt MR, Ording H, Andersen C, Licht PB, Toft P. Early visceral pain predicts chronic pain after laparoscopic cholecystectomy. Pain. 2014 Nov;155(11):2400-7. doi: 10.1016/j.pain.2014.09.019. Epub 2014 Sep 22.
PubMed 25250720Ruiz-Tovar J, Garcia A, Ferrigni C, Duran M. Application of Vitamin E Acetate on Staple Lines and Anastomoses of Roux-en-Y Gastric Bypass: Impact on Postoperative Pain and Acute Phase Reactants. Obes Surg. 2020 Aug;30(8):2988-2993. doi: 10.1007/s11695-020-04635-9.
PubMed 32342266Koh JC, Kong HJ, Kim MH, Hong JH, Seong H, Kim NY, Bai SJ. Comparison of Analgesic and Adverse Effects of Oxycodone- and Fentanyl-Based Patient-Controlled Analgesia in Patients Undergoing Robot-Assisted Laparoscopic Gastrectomy Using a 55:1 Potency Ratio of Oxycodone to Fentanyl: A Retrospective Study. J Pain Res. 2020 Sep 4;13:2197-2204. doi: 10.2147/JPR.S264764. eCollection 2020.
PubMed 32943912
Study at a glance
From the registry record, last updated by the sponsor on 9 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Efficacy of Anrikefon-based Patient-controlled Intravenous Analgesia for Pain Management After Laparoscopic Surgery: a Randomized, Double-blind, Active-controlled Pilot Trial
- ClinicalTrials.gov ID
- NCT07246785
- Acronym / sponsor ID
- 2025R0444
- Conditions
- Laparoscopic Surgery, Visceral Pain, Postoperative, Anrikefon, Patient-controlled Intravenous Analgesia
- Keywords
- Laparoscopic surgery, Visceral pain, Postoperative, Anrikefon, Patient-controlled intravenous analgesia
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- TerminatedReason stopped: The study was terminated due to substantial protocol amendments involving changes in the target population and primary endpoint, rendering previously collected data incompatible with the revised study objective.
- Enrolment
- 13 participants (actual)
- Lead sponsor
- Peking University First HospitalUniversity, hospital or other
- Study start
- 25 Dec 2025 (actual)
- Primary completion
- 11 Feb 2026 (actual)
- Study completion
- 11 Mar 2026 (actual)
- First posted
- 24 Nov 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Visceral pain following laparoscopic surgery is frequently underestimated, yet it is associated with a range of adverse outcomes. Effective visceral pain management should constitute an essential component of postoperative analgesic strategies following laparoscopic procedures. However, conventional analgesic agents, including μ-opioid receptor agonists, lack specificity for visceral pain. Anrikefon, a novel selective peripheral κ-opioid receptor agonist, demonstrates unique efficacy in alleviating visceral pain with a favorable safety profile. Preliminary studies showed that a single intravenous dose of anrikefon effectively alleviates postoperative pain after abdominal surgery with a low risk of adverse effects. The investigators hypothesize that an appropriate dosing regimen of anrikefon administered via patient-controlled intravenous analgesia (PCIA) pump, as part of a multimodal analgesic strategy, can specifically target and alleviate visceral pain after laparoscopic surgery, thereby achieving comprehensive postoperative analgesia.
Detailed description
Approximately 50% to 90% of patients undergoing abdominal surgery experience moderate or severe acute postoperative pain, which primarily comprises somatic, visceral, and inflammatory pain components, with peak intensity typically occurring within the first 24 to 72 hours after surgery. Inadequate management of acute postoperative pain not only increases patients' suffering and impairs their sleep quality, but also increases the risk of postoperative complications, delays postsurgical recovery, prolongs hospital stay, elevates healthcare costs, and even contributes to the development of chronic neuropathic pain.
With advances in minimally invasive techniques and the widespread application of laparoscopic surgery, surgical incisions on the body surface have been significantly reduced, leading to diminished somatic pain. However, the intra-abdominal visceral injury is not necessarily reduced and can even be more substantial in this context, leading to prominent postoperative visceral pain that perioperative clinicians often underestimate. Consequently, effective management of visceral pain should be an essential component of postoperative analgesic strategies following laparoscopic procedures.
Opioids, renowned for their potent analgesic efficacy, serve as the cornerstone of perioperative acute pain management and constitute a critical element of multimodal analgesic regimens. Nevertheless, due to the sparse expression of μ-opioid receptors in visceral pain pathways and their weak modulation of visceral pain afferent signaling, the conventional μ-opioid receptor agonists, such as morphine, exhibit limited effectiveness against visceral pain. Anrikefon is a novel selective peripheral κ-opioid receptor agonist. Due to the high expression levels of κ-opioid receptors within visceral pain pathways, anrikefon exerts an unique therapeutic effect in alleviating visceral pain with a relatively low risk of adverse effects.
Preliminary studies indicate that a single intravenous dose of Anrikefon effectively alleviates pain after abdominal surgery with a low incidence of adverse effects. Additional evidence suggests that patient-controlled intravenous administration of anrikefon provides effective analgesia after orthopedic surgery without respiratory depression or other severe adverse effects. However, the appropriate dosing regimen of anrikefon for patient-controlled intravenous analgesia (PCIA) following laparoscopic surgery remains to be established.
The investigators hypothesize that administering appropriate doses of anrikefon via PCIA pump, as part of a multimodal analgesic regimen that comprises regional nerve blocks targeting somatic pain and nonsteroidal anti-inflammatory drugs (NSAIDs) targeting inflammatory pain, will specifically and effectively alleviate visceral pain following laparoscopic surgery. This pilot trial aims to explore the preliminary efficacy and optimal dosing regimen of anrikefon administered via PCIA after laparoscopic surgery, assess the feasibility of conducting a larger-scale randomized controlled trial, and provide essential parameters for sample size estimation in subsequent investigations.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| High-dose anrikefon group | Experimental | Drug: High-dose anrikefonPostoperative patient-controlled intravenous analgesia is established with anrikefon 1000 μg, diluted with normal saline to 100 ml, and programmed to administer an initial loading dose of 8 ml, followed by 4-ml boluses with a lockout interval of 10 minutes and no continuous background infusion. |
| Medium-dose anrikefon group | Experimental | Drug: Medium-dose anrikefonPostoperative patient-controlled intravenous analgesia is established with anrikefon 750 μg, diluted with normal saline to 100 ml, and programmed to administer an initial loading dose of 8 ml, followed by 4-ml boluses with a lockout interval of 10 minutes and no continuous background infusion. |
| Low-dose anrikefon group | Experimental | Drug: Low-dose anrikefonPostoperative patient-controlled intravenous analgesia is established with anrikefon 500 μg, diluted with normal saline to 100 ml, and programmed to administer an initial loading dose of 8 ml, followed by 4-ml boluses with a lockout interval of 10 minutes and no continuous background infusion. |
| Morphine group | Active comparator | Drug: MorphinePostoperative patient-controlled intravenous analgesia is established with morphine 50 mg, diluted with normal saline to 100 ml, and programmed to administer an initial loading dose of 8 ml, followed by 4-ml boluses with a lockout interval of 10 minutes and no continuous background infusion. |
Who may qualify
- Ages
- 18 to 74 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- Aged ≥ 18 years but < 75 years;
- Scheduled to undergo elective laparoscopic gastrointestinal surgery with an expected duration of ≥1 hour;
- The incisional pain can be covered by the transversus abdominis plane block or rectus sheath block; yet patients still require postoperative patient-controlled intravenous analgesia.
Key exclusion criteria (8 listed)
- Presence of preoperative cognitive impairment (Mini-Mental State Examination [MMSE] score < 27), or inability to communicate due to language barrier;
- Body mass index (BMI) > 30 kg/m² or < 18 kg/m²;
- Presence of poorly controlled or untreated comorbidities, including but not limited to the following: hypertension characterized by a resting systolic blood pressure (SBP) > 180 mmHg and/or diastolic blood pressure (DBP) > 110 mmHg, coronary artery disease with unstable angina or myocardial infarction within 6 months, heart failure rated as New York Heart Association classification ≥ III, severe chronic obstructive pulmonary disease (or in a state of acute exacerbation), severe hepatic insufficiency (Child-Pugh grade C), severe renal insufficiency (estimated glomerular filtration rate < 30 ml/min/1.73m²), or American Society of Anesthesiologists (ASA) physical status classification ≥ IV;
- Continuous use of opioid analgesics for more than 10 days for any reason, or alcohol abuse (average daily intake of pure alcohol > 36 g) within 3 months before screening;
- Preoperative use of opioid or non-opioid analgesics with the interval between the last administration and randomization shorter than five half-lives of the drug or the duration of drug action (whichever is longer);
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| High-dose anrikefonAlso: High-dose anrikefon-based patient-controlled analgesiaPatients in this group receive postoperative patient-controlled intravenous analgesia for 48 hours. The formula comprises anrikefon (10 μg/ml), diluted with normal saline to 100 ml. The analgesic pump is set to deliver an initial loading dose of 8 ml, followed by patient-controlled boluses of 4 ml with a 10-minute lockout interval and no background infusion. | Drug | High-dose anrikefon group |
| Medium-dose anrikefonAlso: Medium-dose anrikefon-based patient-controlled analgesiaPatients in this group receive postoperative patient-controlled intravenous analgesia for 48 hours. The formula comprises anrikefon (7.5 μg/ml), diluted with normal saline to 100 ml. The analgesic pump is set to deliver an initial loading dose of 8 ml, followed by patient-controlled boluses of 4 ml with a 10-minute lockout interval and no background infusion. | Drug | Medium-dose anrikefon group |
| Low-dose anrikefonAlso: Low-dose anrikefon-based patient-controlled analgesiaPatients in this group receive postoperative patient-controlled intravenous analgesia for 48 hours. The formula comprises anrikefon (5 μg/ml), diluted with normal saline to 100 ml. The analgesic pump is set to deliver an initial loading dose of 8 ml, followed by patient-controlled boluses of 4 ml with a 10-minute lockout interval and no background infusion. | Drug | Low-dose anrikefon group |
| MorphineAlso: Morphine-based patient-controlled analgesiaPatients in this group receive postoperative patient-controlled intravenous analgesia for 48 hours. The formula comprises morphine (0.5 mg/ml), diluted with normal saline to 100 ml. The analgesic pump is set to deliver an initial loading dose of 8 ml, followed by patient-controlled boluses of 4 ml with a 10-minute lockout interval and no background infusion. | Drug | Morphine group |
Primary outcome
Time-weighted sum of pain intensity difference (SPID) of movement-evoked visceral pain within 48 hours
Time frame: Within 48 hours after intervention.
Time-weighted SPID is defined as the cumulative sum of the product obtained by multiplying the pain intensity difference at each time point (calculated by subtracting the baseline pain intensity score from the current pain intensity score) by the time difference (the current time point minus the previous time point). Movement-evoked visceral pain intensity will be assessed before intervention and at 0.5, 1, 2, 6, 12, 24, 36, and 48 hours after intervention using an 11-point Numeric Rating Scale (0 = no pain, 10 = the worst pain).
5 secondary outcomes
Time-weighted SPID of visceral pain at rest within 48 hours
Time frame: Within 48 hours after intervention.
Time-weighted SPID of movement-evoked somatic pain within 48 hours
Time frame: Within 48 hours after intervention.
Time-weighted SPID of somatic pain at rest within 48 hours
Time frame: Within 48 hours after intervention.
Time-weighted SPID of movement-evoked overall pain within 48 hours
Time frame: Within 48 hours after intervention.
Time-weighted SPID of overall pain at rest within 48 hours
Time frame: Within 48 hours after intervention.
Results and safety
The study was stopped early (reason given: The study was terminated due to substantial protocol amendments involving changes in the target population and primary endpoint, rendering previously collected data incompatible with the revised study objective.). Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 9 Apr 2026.
- Background: PubMed 37927993Liu Y, Xiao S, Yang H, Lv X, Hou A, Ma Y, Jiang Y, Duan C, Mi W; CAPOPS Group. Postoperative pain-related outcomes and perioperative pain management in China: a population-based study. Lancet Reg Health West Pac. 2023 Jun 10;39:100822. doi: 10.1016/j.lanwpc.2023.100822. eCollection 2023 Oct.
- Background: PubMed 36862937Armstrong RA, Fayaz A, Manning GLP, Moonesinghe SR; Peri-operative Quality Improvement Programme (PQIP) delivery team; Oliver CM; PQIP collaborative. Predicting severe pain after major surgery: a secondary analysis of the Peri-operative Quality Improvement Programme (PQIP) dataset. Anaesthesia. 2023 Jul;78(7):840-852. doi: 10.1111/anae.15984. Epub 2023 Mar 2.
- Background: PubMed 30983589Glare P, Aubrey KR, Myles PS. Transition from acute to chronic pain after surgery. Lancet. 2019 Apr 13;393(10180):1537-1546. doi: 10.1016/S0140-6736(19)30352-6.
- Background: PubMed 12360379Wildbrett P, Oh A, Naundorf D, Volk T, Jacobi CA. Impact of laparoscopic gases on peritoneal microenvironment and essential parameters of cell function. Surg Endosc. 2003 Jan;17(1):78-82. doi: 10.1007/s00464-002-9015-3. Epub 2002 Sep 30.
- Background: PubMed 17333216Papparella A, Noviello C, Romano M, Parmeggiani P, Paciello O, Papparella S. Local and systemic impact of pneumoperitoneum on prepuberal rats. Pediatr Surg Int. 2007 May;23(5):453-7. doi: 10.1007/s00383-006-1860-z.
- Background: PubMed 25561784Hatipoglu S, Akbulut S, Hatipoglu F, Abdullayev R. Effect of laparoscopic abdominal surgery on splanchnic circulation: historical developments. World J Gastroenterol. 2014 Dec 28;20(48):18165-76. doi: 10.3748/wjg.v20.i48.18165.
- Background: PubMed 31701284de Lacy FB, Taura P, Arroyave MC, Trepanier JS, Rios J, Bravo R, Ibarzabal A, Pena R, Deulofeu R, Lacy AM. Impact of pneumoperitoneum on intra-abdominal microcirculation blood flow: an experimental randomized controlled study of two insufflator models during transanal total mesorectal excision : An experimental randomized multi-arm trial with parallel treatment design. Surg Endosc. 2020 Oct;34(10):4494-4503. doi: 10.1007/s00464-019-07236-5. Epub 2019 Nov 7.
- Background: PubMed 29991201Cheong JY, Keshava A, Witting P, Young CJ. Effects of Intraoperative Insufflation With Warmed, Humidified CO2 during Abdominal Surgery: A Review. Ann Coloproctol. 2018 Jun;34(3):125-137. doi: 10.3393/ac.2017.09.26. Epub 2018 Jun 30.
- Background: PubMed 22246042Sikandar S, Dickenson AH. Visceral pain: the ins and outs, the ups and downs. Curr Opin Support Palliat Care. 2012 Mar;6(1):17-26. doi: 10.1097/SPC.0b013e32834f6ec9.
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- Background: PubMed 27499688Choi JB, Kang K, Song MK, Seok S, Kim YH, Kim JE. Pain Characteristics after Total Laparoscopic Hysterectomy. Int J Med Sci. 2016 Jul 5;13(8):562-8. doi: 10.7150/ijms.15875. eCollection 2016.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Dong-Xin Wang, MD, PhD principal investigator
Peking University First Hospital
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 4 study testing High-dose anrikefon, Medium-dose anrikefon and Low-dose anrikefon in people with Laparoscopic Surgery and Visceral Pain, Postoperative, run by Peking University First Hospital at 1 site in China.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: stopped early, as of the sponsor's last update on 9 Apr 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in China. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study was stopped early (reason given: The study was terminated due to substantial protocol amendments involving changes in the target population and primary endpoint, rendering previously collected data incompatible with the revised study objective.). Results are not available in the source record.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Time-weighted sum of pain intensity difference (SPID) of movement-evoked visceral pain within 48 hours (time frame: Within 48 hours after intervention.). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07246785, which also lists 23 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 9 Apr 2026.