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

Not yet recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

180

Phase

  • Not Applicable

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

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:

  • 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
Intervention / Treatment
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

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

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

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)

December 28, 2025

Primary Completion (Estimated)

April 1, 2026

Study Completion (Estimated)

May 1, 2026

Study Registration Dates

First Submitted

December 27, 2025

First Submitted That Met QC Criteria

January 16, 2026

First Posted (Actual)

January 22, 2026

Study Record Updates

Last Update Posted (Actual)

January 22, 2026

Last Update Submitted That Met QC Criteria

January 16, 2026

Last Verified

January 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID 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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