Comparing N-Acetylcysteine (NAC) Versus Alpha-Lipoic Acid (ALA) as Adjuncts for Postoperative Pain Management After Laparoscopic Appendectomy

January 16, 2026 updated by: Eman Mohamed El Mokadem, Ain Shams University

Postoperative pain remains a major concern following laparoscopic appendectomy, despite advances in minimally invasive surgery and multimodal analgesia. Inadequate pain control delays recovery, prolongs hospital stay, and increases opioid consumption with associated adverse effects. Therefore, identifying safe adjunct therapies that enhance analgesia and reduce opioid requirements is an important clinical goal.

Oxidative stress and inflammation play a critical role in the development and maintenance of postoperative pain. Surgical trauma induces the generation of reactive oxygen species, which sensitize peripheral nociceptors and enhance central pain transmission.

Antioxidants capable of modulating oxidative stress and inflammatory pathways may therefore offer analgesic benefits beyond conventional analgesics.

N-Acetylcysteine (NAC), a glutathione precursor, has demonstrated anti-inflammatory and analgesic properties in both experimental and clinical settings. It reduces oxidative stress, improves microcirculation, and modulates nociceptive signaling.

Alpha-Lipoic Acid (ALA) is another potent antioxidant that acts as a cofactor in mitochondrial metabolism and has proven efficacy in neuropathic pain conditions. However, its role in acute postoperative pain has not been fully investigated.

To our knowledge, no clinical trial has directly compared NAC and ALA in the perioperative setting, and their effects following laparoscopic appendectomy remain unstudied. This randomized controlled trial aims to evaluate the efficacy and safety of NAC and ALA as adjuncts to standard analgesia, with the goal of estimating their effect on postoperative opioid consumption and pain intensity. The results will provide preliminary data to guide larger definitive studies.

Aim of the study The aim of this study is to evaluate and compare the efficacy and safety of N-acetylcysteine (NAC) and alpha-lipoic acid (ALA) as adjuncts to standard postoperative analgesia in patients undergoing laparoscopic appendectomy. Specifically, the study seeks to determine their effects on postoperative pain intensity, opioid consumption, and recovery profile in the early postoperative period.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
180

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

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Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Age 18-65 years, either sex

    • ASA physical status I-III
    • Undergoing laparoscopic appendectomy
    • Able to provide informed consent and take oral medications postoperatively

Exclusion Criteria:

  • Chronic opioid use or chronic pain disorder
  • Pregnancy or lactation
  • Hepatic or renal impairment
  • Known hypersensitivity to NAC or ALA
  • Complicated appendicitis requiring open surgery or ICU admission

Exclusion Criteria:

-

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: Other
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Active Comparator: N- acetyl cysteine
Patients of this group will receive 600 mg oral N-acetylcysteine 1-2 hours preoperatively
Dietary supplement: N Acetyl Cysteine
600 mg oral N-acetylcysteine 1-2 hours preoperatively
Active Comparator: Alpha Lipoic acid
Patients of this group will receive 600 mg oral Alpha lipoic acid 1-2 hours preoperatively
Dietary supplement: Alpha-Lipoic Acid (ALA)
600 mg oral alpha-lipoic acid 1-2 hours preoperatively.
Placebo Comparator: Placebo
Matching placebo capsules given at identical intervals.
Other: Placebo
Matching placebo capsules given at identical intervals.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Visual analogue scale (VAS)
Time Frame: At 2 hours, 6 hours, 12 hours , 24 hours , and 48 hours post-surgery
Pain intensity: VAS at 2, 6, 12, 24, and 48 hours post-surgery (0 = no pain, 10 = worst pain)
At 2 hours, 6 hours, 12 hours , 24 hours , and 48 hours post-surgery

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Incidence of Nausea and vomiting
Time Frame: Assessed at 2 hours, 6 hours, 12 hours, 24 hours, and 48 hours post-surgery
assessed on a 3-point scale (0 = none, 1 = mild, 2 = severe)
Assessed at 2 hours, 6 hours, 12 hours, 24 hours, and 48 hours post-surgery
Rescue analgesia
Time Frame: in 24 and 48 hours post surgery
time to first opioid request will be assessed
in 24 and 48 hours post surgery
Occurrence of Adverse effects
Time Frame: Occurrence of adverse effects will be assessed at baseline of the study and at 24 hours and 48 hours post surgery.
Occurrence of adverse effects like dizziness, headache, rash, or gastrointestinal discomfort will be recorded and graded for severity.
Occurrence of adverse effects will be assessed at baseline of the study and at 24 hours and 48 hours post surgery.
Total opioid use
Time Frame: at baseline of the study and at 24 hours and 48 hours post surgery
Total opioid use will be assessed throughout the study period
at baseline of the study and at 24 hours and 48 hours post surgery

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Ain Shams University

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 (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
December 28, 2025

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
April 1, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
May 1, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
December 27, 2025

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
January 16, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
January 22, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
January 22, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
January 16, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
January 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • HM000209

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

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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